// Package executor provides runtime execution capabilities for various AI service providers.
// This file implements the Antigravity executor that proxies requests to the antigravity
// upstream using OAuth credentials.
package executor

import (
	"bufio"
	"bytes"
	"context"
	"crypto/sha256"
	"crypto/tls"
	"encoding/binary"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"math/rand"
	"net/http"
	"net/url"
	"strconv"
	"strings"
	"sync"
	"time"

	"github.com/google/uuid"
	"github.com/router-for-me/CLIProxyAPI/v6/internal/config"
	"github.com/router-for-me/CLIProxyAPI/v6/internal/registry"
	"github.com/router-for-me/CLIProxyAPI/v6/internal/thinking"
	"github.com/router-for-me/CLIProxyAPI/v6/internal/util"
	sdkAuth "github.com/router-for-me/CLIProxyAPI/v6/sdk/auth"
	cliproxyauth "github.com/router-for-me/CLIProxyAPI/v6/sdk/cliproxy/auth"
	cliproxyexecutor "github.com/router-for-me/CLIProxyAPI/v6/sdk/cliproxy/executor"
	sdktranslator "github.com/router-for-me/CLIProxyAPI/v6/sdk/translator"
	log "github.com/sirupsen/logrus"
	"github.com/tidwall/gjson"
	"github.com/tidwall/sjson"
)

const (
	antigravityBaseURLDaily        = "https://daily-cloudcode-pa.googleapis.com"
	antigravitySandboxBaseURLDaily = "https://daily-cloudcode-pa.sandbox.googleapis.com"
	antigravityBaseURLProd         = "https://cloudcode-pa.googleapis.com"
	antigravityCountTokensPath     = "/v1internal:countTokens"
	antigravityStreamPath          = "/v1internal:streamGenerateContent"
	antigravityGeneratePath        = "/v1internal:generateContent"
	antigravityModelsPath          = "/v1internal:fetchAvailableModels"
	antigravityClientID            = "1071006060591-tmhssin2h21lcre235vtolojh4g403ep.apps.googleusercontent.com"
	antigravityClientSecret        = "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"
	defaultAntigravityAgent        = "antigravity/1.18.4 windows/amd64"
	antigravityAuthType            = "antigravity"
	refreshSkew                    = 3000 * time.Second
	systemInstruction              = "<identity> You are Antigravity, a powerful agentic AI coding assistant designed by the Google Deepmind team working on Advanced Agentic Coding. You are pair programming with a USER to solve their coding task. The task may require creating a new codebase, modifying or debugging an existing codebase, or simply answering a question. The USER will send you requests, which you must always prioritize addressing. Along with each USER request, we will attach additional metadata about their current state, such as what files they have open and where their cursor is. This information may or may not be relevant to the coding task, it is up for you to decide. </identity>"
)

var (
	randSource      = rand.New(rand.NewSource(time.Now().UnixNano()))
	randSourceMutex sync.Mutex
)

// AntigravityExecutor proxies requests to the antigravity upstream.
type AntigravityExecutor struct {
	cfg *config.Config
}

// NewAntigravityExecutor creates a new Antigravity executor instance.
//
// Parameters:
//   - cfg: The application configuration
//
// Returns:
//   - *AntigravityExecutor: A new Antigravity executor instance
func NewAntigravityExecutor(cfg *config.Config) *AntigravityExecutor {
	return &AntigravityExecutor{cfg: cfg}
}

// antigravityTransport is a singleton HTTP/1.1 transport shared by all Antigravity requests.
// It is initialized once via antigravityTransportOnce to avoid leaking a new connection pool
// (and the goroutines managing it) on every request.
var (
	antigravityTransport     *http.Transport
	antigravityTransportOnce sync.Once
)

// initAntigravityTransport creates the shared HTTP/1.1 transport exactly once.
func initAntigravityTransport() {
	base, ok := http.DefaultTransport.(*http.Transport)
	if !ok {
		base = &http.Transport{}
	}
	antigravityTransport = base.Clone()
	antigravityTransport.ForceAttemptHTTP2 = false
	// Wipe TLSNextProto to prevent implicit HTTP/2 upgrade
	antigravityTransport.TLSNextProto = make(map[string]func(authority string, c *tls.Conn) http.RoundTripper)
	// Crucial: actively advertise only HTTP/1.1 in the ALPN handshake
	if antigravityTransport.TLSClientConfig == nil {
		antigravityTransport.TLSClientConfig = &tls.Config{}
	}
	antigravityTransport.TLSClientConfig.NextProtos = []string{"http/1.1"}
}

// newAntigravityHTTPClient creates an HTTP client specifically for Antigravity,
// enforcing HTTP/1.1 by disabling HTTP/2 to perfectly mimic Node.js https defaults.
// The underlying Transport is a singleton to avoid leaking connection pools.
func newAntigravityHTTPClient(ctx context.Context, cfg *config.Config, auth *cliproxyauth.Auth, timeout time.Duration) *http.Client {
	antigravityTransportOnce.Do(initAntigravityTransport)

	client := newProxyAwareHTTPClient(ctx, cfg, auth, timeout)
	// If the proxy helper didn't set a custom transport (e.g. SOCKS5), use
	// the shared HTTP/1.1 transport. Custom proxy transports are left as-is
	// because they already carry their own dialer configuration.
	if client.Transport == nil {
		client.Transport = antigravityTransport
	} else if _, isDefault := client.Transport.(*http.Transport); isDefault {
		client.Transport = antigravityTransport
	}
	return client
}

// Identifier returns the executor identifier.
func (e *AntigravityExecutor) Identifier() string { return antigravityAuthType }

// PrepareRequest injects Antigravity credentials into the outgoing HTTP request.
func (e *AntigravityExecutor) PrepareRequest(req *http.Request, auth *cliproxyauth.Auth) error {
	if req == nil {
		return nil
	}
	token, _, errToken := e.ensureAccessToken(req.Context(), auth)
	if errToken != nil {
		return errToken
	}
	if strings.TrimSpace(token) == "" {
		return statusErr{code: http.StatusUnauthorized, msg: "missing access token"}
	}
	req.Header.Set("Authorization", "Bearer "+token)
	return nil
}

// HttpRequest injects Antigravity credentials into the request and executes it.
func (e *AntigravityExecutor) HttpRequest(ctx context.Context, auth *cliproxyauth.Auth, req *http.Request) (*http.Response, error) {
	if req == nil {
		return nil, fmt.Errorf("antigravity executor: request is nil")
	}
	if ctx == nil {
		ctx = req.Context()
	}
	httpReq := req.WithContext(ctx)
	if err := e.PrepareRequest(httpReq, auth); err != nil {
		return nil, err
	}
	httpReq.Close = true
	httpReq.Header.Del("Accept")
	scrubProxyAndFingerprintHeaders(httpReq)
	httpClient := newAntigravityHTTPClient(ctx, e.cfg, auth, 0)
	return httpClient.Do(httpReq)
}

// Execute performs a non-streaming request to the Antigravity API.
func (e *AntigravityExecutor) Execute(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (resp cliproxyexecutor.Response, err error) {
	if opts.Alt == "responses/compact" {
		return resp, statusErr{code: http.StatusNotImplemented, msg: "/responses/compact not supported"}
	}
	baseModel := thinking.ParseSuffix(req.Model).ModelName
	isClaude := strings.Contains(strings.ToLower(baseModel), "claude")

	if isClaude || strings.Contains(baseModel, "gemini-3-pro") {
		return e.executeClaudeNonStream(ctx, auth, req, opts)
	}

	token, updatedAuth, errToken := e.ensureAccessToken(ctx, auth)
	if errToken != nil {
		return resp, errToken
	}
	if updatedAuth != nil {
		auth = updatedAuth
	}

	reporter := newUsageReporter(ctx, e.Identifier(), baseModel, auth)
	defer reporter.trackFailure(ctx, &err)

	from := opts.SourceFormat
	to := sdktranslator.FromString("antigravity")

	originalPayloadSource := req.Payload
	if len(opts.OriginalRequest) > 0 {
		originalPayloadSource = opts.OriginalRequest
	}
	originalPayload := originalPayloadSource
	originalTranslated := sdktranslator.TranslateRequest(from, to, baseModel, originalPayload, false)
	translated := sdktranslator.TranslateRequest(from, to, baseModel, req.Payload, false)

	translated, err = thinking.ApplyThinking(translated, req.Model, from.String(), to.String(), e.Identifier())
	if err != nil {
		return resp, err
	}

	requestedModel := payloadRequestedModel(opts, req.Model)
	translated = applyPayloadConfigWithRoot(e.cfg, baseModel, "antigravity", "request", translated, originalTranslated, requestedModel)

	baseURLs := antigravityBaseURLFallbackOrder(auth)
	httpClient := newAntigravityHTTPClient(ctx, e.cfg, auth, 0)

	attempts := antigravityRetryAttempts(auth, e.cfg)

attemptLoop:
	for attempt := 0; attempt < attempts; attempt++ {
		var lastStatus int
		var lastBody []byte
		var lastErr error

		for idx, baseURL := range baseURLs {
			httpReq, errReq := e.buildRequest(ctx, auth, token, baseModel, translated, false, opts.Alt, baseURL)
			if errReq != nil {
				err = errReq
				return resp, err
			}

			httpResp, errDo := httpClient.Do(httpReq)
			if errDo != nil {
				recordAPIResponseError(ctx, e.cfg, errDo)
				if errors.Is(errDo, context.Canceled) || errors.Is(errDo, context.DeadlineExceeded) {
					return resp, errDo
				}
				lastStatus = 0
				lastBody = nil
				lastErr = errDo
				if idx+1 < len(baseURLs) {
					log.Debugf("antigravity executor: request error on base url %s, retrying with fallback base url: %s", baseURL, baseURLs[idx+1])
					continue
				}
				err = errDo
				return resp, err
			}

			recordAPIResponseMetadata(ctx, e.cfg, httpResp.StatusCode, httpResp.Header.Clone())
			bodyBytes, errRead := io.ReadAll(httpResp.Body)
			if errClose := httpResp.Body.Close(); errClose != nil {
				log.Errorf("antigravity executor: close response body error: %v", errClose)
			}
			if errRead != nil {
				recordAPIResponseError(ctx, e.cfg, errRead)
				err = errRead
				return resp, err
			}
			appendAPIResponseChunk(ctx, e.cfg, bodyBytes)

			if httpResp.StatusCode < http.StatusOK || httpResp.StatusCode >= http.StatusMultipleChoices {
				log.Debugf("antigravity executor: upstream error status: %d, body: %s", httpResp.StatusCode, summarizeErrorBody(httpResp.Header.Get("Content-Type"), bodyBytes))
				lastStatus = httpResp.StatusCode
				lastBody = append([]byte(nil), bodyBytes...)
				lastErr = nil
				if httpResp.StatusCode == http.StatusTooManyRequests && idx+1 < len(baseURLs) {
					log.Debugf("antigravity executor: rate limited on base url %s, retrying with fallback base url: %s", baseURL, baseURLs[idx+1])
					continue
				}
				if antigravityShouldRetryNoCapacity(httpResp.StatusCode, bodyBytes) {
					if idx+1 < len(baseURLs) {
						log.Debugf("antigravity executor: no capacity on base url %s, retrying with fallback base url: %s", baseURL, baseURLs[idx+1])
						continue
					}
					if attempt+1 < attempts {
						delay := antigravityNoCapacityRetryDelay(attempt)
						log.Debugf("antigravity executor: no capacity for model %s, retrying in %s (attempt %d/%d)", baseModel, delay, attempt+1, attempts)
						if errWait := antigravityWait(ctx, delay); errWait != nil {
							return resp, errWait
						}
						continue attemptLoop
					}
				}
				sErr := statusErr{code: httpResp.StatusCode, msg: string(bodyBytes)}
				if httpResp.StatusCode == http.StatusTooManyRequests {
					if retryAfter, parseErr := parseRetryDelay(bodyBytes); parseErr == nil && retryAfter != nil {
						sErr.retryAfter = retryAfter
					}
				}
				err = sErr
				return resp, err
			}

			reporter.publish(ctx, parseAntigravityUsage(bodyBytes))
			var param any
			converted := sdktranslator.TranslateNonStream(ctx, to, from, req.Model, opts.OriginalRequest, translated, bodyBytes, &param)
			resp = cliproxyexecutor.Response{Payload: []byte(converted), Headers: httpResp.Header.Clone()}
			reporter.ensurePublished(ctx)
			return resp, nil
		}

		switch {
		case lastStatus != 0:
			sErr := statusErr{code: lastStatus, msg: string(lastBody)}
			if lastStatus == http.StatusTooManyRequests {
				if retryAfter, parseErr := parseRetryDelay(lastBody); parseErr == nil && retryAfter != nil {
					sErr.retryAfter = retryAfter
				}
			}
			err = sErr
		case lastErr != nil:
			err = lastErr
		default:
			err = statusErr{code: http.StatusServiceUnavailable, msg: "antigravity executor: no base url available"}
		}
		return resp, err
	}

	return resp, err
}

// executeClaudeNonStream performs a claude non-streaming request to the Antigravity API.
func (e *AntigravityExecutor) executeClaudeNonStream(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (resp cliproxyexecutor.Response, err error) {
	baseModel := thinking.ParseSuffix(req.Model).ModelName

	token, updatedAuth, errToken := e.ensureAccessToken(ctx, auth)
	if errToken != nil {
		return resp, errToken
	}
	if updatedAuth != nil {
		auth = updatedAuth
	}

	reporter := newUsageReporter(ctx, e.Identifier(), baseModel, auth)
	defer reporter.trackFailure(ctx, &err)

	from := opts.SourceFormat
	to := sdktranslator.FromString("antigravity")

	originalPayloadSource := req.Payload
	if len(opts.OriginalRequest) > 0 {
		originalPayloadSource = opts.OriginalRequest
	}
	originalPayload := originalPayloadSource
	originalTranslated := sdktranslator.TranslateRequest(from, to, baseModel, originalPayload, true)
	translated := sdktranslator.TranslateRequest(from, to, baseModel, req.Payload, true)

	translated, err = thinking.ApplyThinking(translated, req.Model, from.String(), to.String(), e.Identifier())
	if err != nil {
		return resp, err
	}

	requestedModel := payloadRequestedModel(opts, req.Model)
	translated = applyPayloadConfigWithRoot(e.cfg, baseModel, "antigravity", "request", translated, originalTranslated, requestedModel)

	baseURLs := antigravityBaseURLFallbackOrder(auth)
	httpClient := newAntigravityHTTPClient(ctx, e.cfg, auth, 0)

	attempts := antigravityRetryAttempts(auth, e.cfg)

attemptLoop:
	for attempt := 0; attempt < attempts; attempt++ {
		var lastStatus int
		var lastBody []byte
		var lastErr error

		for idx, baseURL := range baseURLs {
			httpReq, errReq := e.buildRequest(ctx, auth, token, baseModel, translated, true, opts.Alt, baseURL)
			if errReq != nil {
				err = errReq
				return resp, err
			}

			httpResp, errDo := httpClient.Do(httpReq)
			if errDo != nil {
				recordAPIResponseError(ctx, e.cfg, errDo)
				if errors.Is(errDo, context.Canceled) || errors.Is(errDo, context.DeadlineExceeded) {
					return resp, errDo
				}
				lastStatus = 0
				lastBody = nil
				lastErr = errDo
				if idx+1 < len(baseURLs) {
					log.Debugf("antigravity executor: request error on base url %s, retrying with fallback base url: %s", baseURL, baseURLs[idx+1])
					continue
				}
				err = errDo
				return resp, err
			}
			recordAPIResponseMetadata(ctx, e.cfg, httpResp.StatusCode, httpResp.Header.Clone())
			if httpResp.StatusCode < http.StatusOK || httpResp.StatusCode >= http.StatusMultipleChoices {
				bodyBytes, errRead := io.ReadAll(httpResp.Body)
				if errClose := httpResp.Body.Close(); errClose != nil {
					log.Errorf("antigravity executor: close response body error: %v", errClose)
				}
				if errRead != nil {
					recordAPIResponseError(ctx, e.cfg, errRead)
					if errors.Is(errRead, context.Canceled) || errors.Is(errRead, context.DeadlineExceeded) {
						err = errRead
						return resp, err
					}
					if errCtx := ctx.Err(); errCtx != nil {
						err = errCtx
						return resp, err
					}
					lastStatus = 0
					lastBody = nil
					lastErr = errRead
					if idx+1 < len(baseURLs) {
						log.Debugf("antigravity executor: read error on base url %s, retrying with fallback base url: %s", baseURL, baseURLs[idx+1])
						continue
					}
					err = errRead
					return resp, err
				}
				appendAPIResponseChunk(ctx, e.cfg, bodyBytes)
				lastStatus = httpResp.StatusCode
				lastBody = append([]byte(nil), bodyBytes...)
				lastErr = nil
				if httpResp.StatusCode == http.StatusTooManyRequests && idx+1 < len(baseURLs) {
					log.Debugf("antigravity executor: rate limited on base url %s, retrying with fallback base url: %s", baseURL, baseURLs[idx+1])
					continue
				}
				if antigravityShouldRetryNoCapacity(httpResp.StatusCode, bodyBytes) {
					if idx+1 < len(baseURLs) {
						log.Debugf("antigravity executor: no capacity on base url %s, retrying with fallback base url: %s", baseURL, baseURLs[idx+1])
						continue
					}
					if attempt+1 < attempts {
						delay := antigravityNoCapacityRetryDelay(attempt)
						log.Debugf("antigravity executor: no capacity for model %s, retrying in %s (attempt %d/%d)", baseModel, delay, attempt+1, attempts)
						if errWait := antigravityWait(ctx, delay); errWait != nil {
							return resp, errWait
						}
						continue attemptLoop
					}
				}
				sErr := statusErr{code: httpResp.StatusCode, msg: string(bodyBytes)}
				if httpResp.StatusCode == http.StatusTooManyRequests {
					if retryAfter, parseErr := parseRetryDelay(bodyBytes); parseErr == nil && retryAfter != nil {
						sErr.retryAfter = retryAfter
					}
				}
				err = sErr
				return resp, err
			}

			out := make(chan cliproxyexecutor.StreamChunk)
			go func(resp *http.Response) {
				defer close(out)
				defer func() {
					if errClose := resp.Body.Close(); errClose != nil {
						log.Errorf("antigravity executor: close response body error: %v", errClose)
					}
				}()
				scanner := bufio.NewScanner(resp.Body)
				scanner.Buffer(nil, streamScannerBuffer)
				for scanner.Scan() {
					line := scanner.Bytes()
					appendAPIResponseChunk(ctx, e.cfg, line)

					// Filter usage metadata for all models
					// Only retain usage statistics in the terminal chunk
					line = FilterSSEUsageMetadata(line)

					payload := jsonPayload(line)
					if payload == nil {
						continue
					}

					if detail, ok := parseAntigravityStreamUsage(payload); ok {
						reporter.publish(ctx, detail)
					}

					out <- cliproxyexecutor.StreamChunk{Payload: payload}
				}
				if errScan := scanner.Err(); errScan != nil {
					recordAPIResponseError(ctx, e.cfg, errScan)
					reporter.publishFailure(ctx)
					out <- cliproxyexecutor.StreamChunk{Err: errScan}
				} else {
					reporter.ensurePublished(ctx)
				}
			}(httpResp)

			var buffer bytes.Buffer
			for chunk := range out {
				if chunk.Err != nil {
					return resp, chunk.Err
				}
				if len(chunk.Payload) > 0 {
					_, _ = buffer.Write(chunk.Payload)
					_, _ = buffer.Write([]byte("\n"))
				}
			}
			resp = cliproxyexecutor.Response{Payload: e.convertStreamToNonStream(buffer.Bytes())}

			reporter.publish(ctx, parseAntigravityUsage(resp.Payload))
			var param any
			converted := sdktranslator.TranslateNonStream(ctx, to, from, req.Model, opts.OriginalRequest, translated, resp.Payload, &param)
			resp = cliproxyexecutor.Response{Payload: []byte(converted), Headers: httpResp.Header.Clone()}
			reporter.ensurePublished(ctx)

			return resp, nil
		}

		switch {
		case lastStatus != 0:
			sErr := statusErr{code: lastStatus, msg: string(lastBody)}
			if lastStatus == http.StatusTooManyRequests {
				if retryAfter, parseErr := parseRetryDelay(lastBody); parseErr == nil && retryAfter != nil {
					sErr.retryAfter = retryAfter
				}
			}
			err = sErr
		case lastErr != nil:
			err = lastErr
		default:
			err = statusErr{code: http.StatusServiceUnavailable, msg: "antigravity executor: no base url available"}
		}
		return resp, err
	}

	return resp, err
}

func (e *AntigravityExecutor) convertStreamToNonStream(stream []byte) []byte {
	responseTemplate := ""
	var traceID string
	var finishReason string
	var modelVersion string
	var responseID string
	var role string
	var usageRaw string
	parts := make([]map[string]interface{}, 0)
	var pendingKind string
	var pendingText strings.Builder
	var pendingThoughtSig string

	flushPending := func() {
		if pendingKind == "" {
			return
		}
		text := pendingText.String()
		switch pendingKind {
		case "text":
			if strings.TrimSpace(text) == "" {
				pendingKind = ""
				pendingText.Reset()
				pendingThoughtSig = ""
				return
			}
			parts = append(parts, map[string]interface{}{"text": text})
		case "thought":
			if strings.TrimSpace(text) == "" && pendingThoughtSig == "" {
				pendingKind = ""
				pendingText.Reset()
				pendingThoughtSig = ""
				return
			}
			part := map[string]interface{}{"thought": true}
			part["text"] = text
			if pendingThoughtSig != "" {
				part["thoughtSignature"] = pendingThoughtSig
			}
			parts = append(parts, part)
		}
		pendingKind = ""
		pendingText.Reset()
		pendingThoughtSig = ""
	}

	normalizePart := func(partResult gjson.Result) map[string]interface{} {
		var m map[string]interface{}
		_ = json.Unmarshal([]byte(partResult.Raw), &m)
		if m == nil {
			m = map[string]interface{}{}
		}
		sig := partResult.Get("thoughtSignature").String()
		if sig == "" {
			sig = partResult.Get("thought_signature").String()
		}
		if sig != "" {
			m["thoughtSignature"] = sig
			delete(m, "thought_signature")
		}
		if inlineData, ok := m["inline_data"]; ok {
			m["inlineData"] = inlineData
			delete(m, "inline_data")
		}
		return m
	}

	for _, line := range bytes.Split(stream, []byte("\n")) {
		trimmed := bytes.TrimSpace(line)
		if len(trimmed) == 0 || !gjson.ValidBytes(trimmed) {
			continue
		}

		root := gjson.ParseBytes(trimmed)
		responseNode := root.Get("response")
		if !responseNode.Exists() {
			if root.Get("candidates").Exists() {
				responseNode = root
			} else {
				continue
			}
		}
		responseTemplate = responseNode.Raw

		if traceResult := root.Get("traceId"); traceResult.Exists() && traceResult.String() != "" {
			traceID = traceResult.String()
		}

		if roleResult := responseNode.Get("candidates.0.content.role"); roleResult.Exists() {
			role = roleResult.String()
		}

		if finishResult := responseNode.Get("candidates.0.finishReason"); finishResult.Exists() && finishResult.String() != "" {
			finishReason = finishResult.String()
		}

		if modelResult := responseNode.Get("modelVersion"); modelResult.Exists() && modelResult.String() != "" {
			modelVersion = modelResult.String()
		}
		if responseIDResult := responseNode.Get("responseId"); responseIDResult.Exists() && responseIDResult.String() != "" {
			responseID = responseIDResult.String()
		}
		if usageResult := responseNode.Get("usageMetadata"); usageResult.Exists() {
			usageRaw = usageResult.Raw
		} else if usageMetadataResult := root.Get("usageMetadata"); usageMetadataResult.Exists() {
			usageRaw = usageMetadataResult.Raw
		}

		if partsResult := responseNode.Get("candidates.0.content.parts"); partsResult.IsArray() {
			for _, part := range partsResult.Array() {
				hasFunctionCall := part.Get("functionCall").Exists()
				hasInlineData := part.Get("inlineData").Exists() || part.Get("inline_data").Exists()
				sig := part.Get("thoughtSignature").String()
				if sig == "" {
					sig = part.Get("thought_signature").String()
				}
				text := part.Get("text").String()
				thought := part.Get("thought").Bool()

				if hasFunctionCall || hasInlineData {
					flushPending()
					parts = append(parts, normalizePart(part))
					continue
				}

				if thought || part.Get("text").Exists() {
					kind := "text"
					if thought {
						kind = "thought"
					}
					if pendingKind != "" && pendingKind != kind {
						flushPending()
					}
					pendingKind = kind
					pendingText.WriteString(text)
					if kind == "thought" && sig != "" {
						pendingThoughtSig = sig
					}
					continue
				}

				flushPending()
				parts = append(parts, normalizePart(part))
			}
		}
	}
	flushPending()

	if responseTemplate == "" {
		responseTemplate = `{"candidates":[{"content":{"role":"model","parts":[]}}]}`
	}

	partsJSON, _ := json.Marshal(parts)
	responseTemplate, _ = sjson.SetRaw(responseTemplate, "candidates.0.content.parts", string(partsJSON))
	if role != "" {
		responseTemplate, _ = sjson.Set(responseTemplate, "candidates.0.content.role", role)
	}
	if finishReason != "" {
		responseTemplate, _ = sjson.Set(responseTemplate, "candidates.0.finishReason", finishReason)
	}
	if modelVersion != "" {
		responseTemplate, _ = sjson.Set(responseTemplate, "modelVersion", modelVersion)
	}
	if responseID != "" {
		responseTemplate, _ = sjson.Set(responseTemplate, "responseId", responseID)
	}
	if usageRaw != "" {
		responseTemplate, _ = sjson.SetRaw(responseTemplate, "usageMetadata", usageRaw)
	} else if !gjson.Get(responseTemplate, "usageMetadata").Exists() {
		responseTemplate, _ = sjson.Set(responseTemplate, "usageMetadata.promptTokenCount", 0)
		responseTemplate, _ = sjson.Set(responseTemplate, "usageMetadata.candidatesTokenCount", 0)
		responseTemplate, _ = sjson.Set(responseTemplate, "usageMetadata.totalTokenCount", 0)
	}

	output := `{"response":{},"traceId":""}`
	output, _ = sjson.SetRaw(output, "response", responseTemplate)
	if traceID != "" {
		output, _ = sjson.Set(output, "traceId", traceID)
	}
	return []byte(output)
}

// ExecuteStream performs a streaming request to the Antigravity API.
func (e *AntigravityExecutor) ExecuteStream(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (_ *cliproxyexecutor.StreamResult, err error) {
	if opts.Alt == "responses/compact" {
		return nil, statusErr{code: http.StatusNotImplemented, msg: "/responses/compact not supported"}
	}
	baseModel := thinking.ParseSuffix(req.Model).ModelName

	ctx = context.WithValue(ctx, "alt", "")

	token, updatedAuth, errToken := e.ensureAccessToken(ctx, auth)
	if errToken != nil {
		return nil, errToken
	}
	if updatedAuth != nil {
		auth = updatedAuth
	}

	reporter := newUsageReporter(ctx, e.Identifier(), baseModel, auth)
	defer reporter.trackFailure(ctx, &err)

	from := opts.SourceFormat
	to := sdktranslator.FromString("antigravity")

	originalPayloadSource := req.Payload
	if len(opts.OriginalRequest) > 0 {
		originalPayloadSource = opts.OriginalRequest
	}
	originalPayload := originalPayloadSource
	originalTranslated := sdktranslator.TranslateRequest(from, to, baseModel, originalPayload, true)
	translated := sdktranslator.TranslateRequest(from, to, baseModel, req.Payload, true)

	translated, err = thinking.ApplyThinking(translated, req.Model, from.String(), to.String(), e.Identifier())
	if err != nil {
		return nil, err
	}

	requestedModel := payloadRequestedModel(opts, req.Model)
	translated = applyPayloadConfigWithRoot(e.cfg, baseModel, "antigravity", "request", translated, originalTranslated, requestedModel)

	baseURLs := antigravityBaseURLFallbackOrder(auth)
	httpClient := newAntigravityHTTPClient(ctx, e.cfg, auth, 0)

	attempts := antigravityRetryAttempts(auth, e.cfg)

attemptLoop:
	for attempt := 0; attempt < attempts; attempt++ {
		var lastStatus int
		var lastBody []byte
		var lastErr error

		for idx, baseURL := range baseURLs {
			httpReq, errReq := e.buildRequest(ctx, auth, token, baseModel, translated, true, opts.Alt, baseURL)
			if errReq != nil {
				err = errReq
				return nil, err
			}
			httpResp, errDo := httpClient.Do(httpReq)
			if errDo != nil {
				recordAPIResponseError(ctx, e.cfg, errDo)
				if errors.Is(errDo, context.Canceled) || errors.Is(errDo, context.DeadlineExceeded) {
					return nil, errDo
				}
				lastStatus = 0
				lastBody = nil
				lastErr = errDo
				if idx+1 < len(baseURLs) {
					log.Debugf("antigravity executor: request error on base url %s, retrying with fallback base url: %s", baseURL, baseURLs[idx+1])
					continue
				}
				err = errDo
				return nil, err
			}
			recordAPIResponseMetadata(ctx, e.cfg, httpResp.StatusCode, httpResp.Header.Clone())
			if httpResp.StatusCode < http.StatusOK || httpResp.StatusCode >= http.StatusMultipleChoices {
				bodyBytes, errRead := io.ReadAll(httpResp.Body)
				if errClose := httpResp.Body.Close(); errClose != nil {
					log.Errorf("antigravity executor: close response body error: %v", errClose)
				}
				if errRead != nil {
					recordAPIResponseError(ctx, e.cfg, errRead)
					if errors.Is(errRead, context.Canceled) || errors.Is(errRead, context.DeadlineExceeded) {
						err = errRead
						return nil, err
					}
					if errCtx := ctx.Err(); errCtx != nil {
						err = errCtx
						return nil, err
					}
					lastStatus = 0
					lastBody = nil
					lastErr = errRead
					if idx+1 < len(baseURLs) {
						log.Debugf("antigravity executor: read error on base url %s, retrying with fallback base url: %s", baseURL, baseURLs[idx+1])
						continue
					}
					err = errRead
					return nil, err
				}
				appendAPIResponseChunk(ctx, e.cfg, bodyBytes)
				lastStatus = httpResp.StatusCode
				lastBody = append([]byte(nil), bodyBytes...)
				lastErr = nil
				if httpResp.StatusCode == http.StatusTooManyRequests && idx+1 < len(baseURLs) {
					log.Debugf("antigravity executor: rate limited on base url %s, retrying with fallback base url: %s", baseURL, baseURLs[idx+1])
					continue
				}
				if antigravityShouldRetryNoCapacity(httpResp.StatusCode, bodyBytes) {
					if idx+1 < len(baseURLs) {
						log.Debugf("antigravity executor: no capacity on base url %s, retrying with fallback base url: %s", baseURL, baseURLs[idx+1])
						continue
					}
					if attempt+1 < attempts {
						delay := antigravityNoCapacityRetryDelay(attempt)
						log.Debugf("antigravity executor: no capacity for model %s, retrying in %s (attempt %d/%d)", baseModel, delay, attempt+1, attempts)
						if errWait := antigravityWait(ctx, delay); errWait != nil {
							return nil, errWait
						}
						continue attemptLoop
					}
				}
				sErr := statusErr{code: httpResp.StatusCode, msg: string(bodyBytes)}
				if httpResp.StatusCode == http.StatusTooManyRequests {
					if retryAfter, parseErr := parseRetryDelay(bodyBytes); parseErr == nil && retryAfter != nil {
						sErr.retryAfter = retryAfter
					}
				}
				err = sErr
				return nil, err
			}

			out := make(chan cliproxyexecutor.StreamChunk)
			go func(resp *http.Response) {
				defer close(out)
				defer func() {
					if errClose := resp.Body.Close(); errClose != nil {
						log.Errorf("antigravity executor: close response body error: %v", errClose)
					}
				}()
				scanner := bufio.NewScanner(resp.Body)
				scanner.Buffer(nil, streamScannerBuffer)
				var param any
				for scanner.Scan() {
					line := scanner.Bytes()
					appendAPIResponseChunk(ctx, e.cfg, line)

					// Filter usage metadata for all models
					// Only retain usage statistics in the terminal chunk
					line = FilterSSEUsageMetadata(line)

					payload := jsonPayload(line)
					if payload == nil {
						continue
					}

					if detail, ok := parseAntigravityStreamUsage(payload); ok {
						reporter.publish(ctx, detail)
					}

					chunks := sdktranslator.TranslateStream(ctx, to, from, req.Model, opts.OriginalRequest, translated, bytes.Clone(payload), &param)
					for i := range chunks {
						out <- cliproxyexecutor.StreamChunk{Payload: []byte(chunks[i])}
					}
				}
				tail := sdktranslator.TranslateStream(ctx, to, from, req.Model, opts.OriginalRequest, translated, []byte("[DONE]"), &param)
				for i := range tail {
					out <- cliproxyexecutor.StreamChunk{Payload: []byte(tail[i])}
				}
				if errScan := scanner.Err(); errScan != nil {
					recordAPIResponseError(ctx, e.cfg, errScan)
					reporter.publishFailure(ctx)
					out <- cliproxyexecutor.StreamChunk{Err: errScan}
				} else {
					reporter.ensurePublished(ctx)
				}
			}(httpResp)
			return &cliproxyexecutor.StreamResult{Headers: httpResp.Header.Clone(), Chunks: out}, nil
		}

		switch {
		case lastStatus != 0:
			sErr := statusErr{code: lastStatus, msg: string(lastBody)}
			if lastStatus == http.StatusTooManyRequests {
				if retryAfter, parseErr := parseRetryDelay(lastBody); parseErr == nil && retryAfter != nil {
					sErr.retryAfter = retryAfter
				}
			}
			err = sErr
		case lastErr != nil:
			err = lastErr
		default:
			err = statusErr{code: http.StatusServiceUnavailable, msg: "antigravity executor: no base url available"}
		}
		return nil, err
	}

	return nil, err
}

// Refresh refreshes the authentication credentials using the refresh token.
func (e *AntigravityExecutor) Refresh(ctx context.Context, auth *cliproxyauth.Auth) (*cliproxyauth.Auth, error) {
	if auth == nil {
		return auth, nil
	}
	updated, errRefresh := e.refreshToken(ctx, auth.Clone())
	if errRefresh != nil {
		return nil, errRefresh
	}
	return updated, nil
}

// CountTokens counts tokens for the given request using the Antigravity API.
func (e *AntigravityExecutor) CountTokens(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (cliproxyexecutor.Response, error) {
	baseModel := thinking.ParseSuffix(req.Model).ModelName

	token, updatedAuth, errToken := e.ensureAccessToken(ctx, auth)
	if errToken != nil {
		return cliproxyexecutor.Response{}, errToken
	}
	if updatedAuth != nil {
		auth = updatedAuth
	}
	if strings.TrimSpace(token) == "" {
		return cliproxyexecutor.Response{}, statusErr{code: http.StatusUnauthorized, msg: "missing access token"}
	}

	from := opts.SourceFormat
	to := sdktranslator.FromString("antigravity")
	respCtx := context.WithValue(ctx, "alt", opts.Alt)

	// Prepare payload once (doesn't depend on baseURL)
	payload := sdktranslator.TranslateRequest(from, to, baseModel, req.Payload, false)

	payload, err := thinking.ApplyThinking(payload, req.Model, from.String(), to.String(), e.Identifier())
	if err != nil {
		return cliproxyexecutor.Response{}, err
	}

	payload = deleteJSONField(payload, "project")
	payload = deleteJSONField(payload, "model")
	payload = deleteJSONField(payload, "request.safetySettings")

	baseURLs := antigravityBaseURLFallbackOrder(auth)
	httpClient := newAntigravityHTTPClient(ctx, e.cfg, auth, 0)

	var authID, authLabel, authType, authValue string
	if auth != nil {
		authID = auth.ID
		authLabel = auth.Label
		authType, authValue = auth.AccountInfo()
	}

	var lastStatus int
	var lastBody []byte
	var lastErr error

	for idx, baseURL := range baseURLs {
		base := strings.TrimSuffix(baseURL, "/")
		if base == "" {
			base = buildBaseURL(auth)
		}

		var requestURL strings.Builder
		requestURL.WriteString(base)
		requestURL.WriteString(antigravityCountTokensPath)
		if opts.Alt != "" {
			requestURL.WriteString("?$alt=")
			requestURL.WriteString(url.QueryEscape(opts.Alt))
		}

		httpReq, errReq := http.NewRequestWithContext(ctx, http.MethodPost, requestURL.String(), bytes.NewReader(payload))
		if errReq != nil {
			return cliproxyexecutor.Response{}, errReq
		}
		httpReq.Close = true
		httpReq.Header.Set("Content-Type", "application/json")
		httpReq.Header.Set("Authorization", "Bearer "+token)
		httpReq.Header.Set("User-Agent", resolveUserAgent(auth))
		httpReq.Header.Del("X-Forwarded-For")
		httpReq.Header.Del("X-Forwarded-Host")
		httpReq.Header.Del("X-Forwarded-Proto")
		httpReq.Header.Del("X-Forwarded-Port")
		httpReq.Header.Del("X-Real-IP")
		httpReq.Header.Del("Forwarded")
		httpReq.Header.Del("Via")
		if host := resolveHost(base); host != "" {
			httpReq.Host = host
		}

		recordAPIRequest(ctx, e.cfg, upstreamRequestLog{
			URL:       requestURL.String(),
			Method:    http.MethodPost,
			Headers:   httpReq.Header.Clone(),
			Body:      payload,
			Provider:  e.Identifier(),
			AuthID:    authID,
			AuthLabel: authLabel,
			AuthType:  authType,
			AuthValue: authValue,
		})

		httpResp, errDo := httpClient.Do(httpReq)
		if errDo != nil {
			recordAPIResponseError(ctx, e.cfg, errDo)
			if errors.Is(errDo, context.Canceled) || errors.Is(errDo, context.DeadlineExceeded) {
				return cliproxyexecutor.Response{}, errDo
			}
			lastStatus = 0
			lastBody = nil
			lastErr = errDo
			if idx+1 < len(baseURLs) {
				log.Debugf("antigravity executor: request error on base url %s, retrying with fallback base url: %s", baseURL, baseURLs[idx+1])
				continue
			}
			return cliproxyexecutor.Response{}, errDo
		}

		recordAPIResponseMetadata(ctx, e.cfg, httpResp.StatusCode, httpResp.Header.Clone())
		bodyBytes, errRead := io.ReadAll(httpResp.Body)
		if errClose := httpResp.Body.Close(); errClose != nil {
			log.Errorf("antigravity executor: close response body error: %v", errClose)
		}
		if errRead != nil {
			recordAPIResponseError(ctx, e.cfg, errRead)
			return cliproxyexecutor.Response{}, errRead
		}
		appendAPIResponseChunk(ctx, e.cfg, bodyBytes)

		if httpResp.StatusCode >= http.StatusOK && httpResp.StatusCode < http.StatusMultipleChoices {
			count := gjson.GetBytes(bodyBytes, "totalTokens").Int()
			translated := sdktranslator.TranslateTokenCount(respCtx, to, from, count, bodyBytes)
			return cliproxyexecutor.Response{Payload: []byte(translated), Headers: httpResp.Header.Clone()}, nil
		}

		lastStatus = httpResp.StatusCode
		lastBody = append([]byte(nil), bodyBytes...)
		lastErr = nil
		if httpResp.StatusCode == http.StatusTooManyRequests && idx+1 < len(baseURLs) {
			log.Debugf("antigravity executor: rate limited on base url %s, retrying with fallback base url: %s", baseURL, baseURLs[idx+1])
			continue
		}
		sErr := statusErr{code: httpResp.StatusCode, msg: string(bodyBytes)}
		if httpResp.StatusCode == http.StatusTooManyRequests {
			if retryAfter, parseErr := parseRetryDelay(bodyBytes); parseErr == nil && retryAfter != nil {
				sErr.retryAfter = retryAfter
			}
		}
		return cliproxyexecutor.Response{}, sErr
	}

	switch {
	case lastStatus != 0:
		sErr := statusErr{code: lastStatus, msg: string(lastBody)}
		if lastStatus == http.StatusTooManyRequests {
			if retryAfter, parseErr := parseRetryDelay(lastBody); parseErr == nil && retryAfter != nil {
				sErr.retryAfter = retryAfter
			}
		}
		return cliproxyexecutor.Response{}, sErr
	case lastErr != nil:
		return cliproxyexecutor.Response{}, lastErr
	default:
		return cliproxyexecutor.Response{}, statusErr{code: http.StatusServiceUnavailable, msg: "antigravity executor: no base url available"}
	}
}

// FetchAntigravityModels retrieves available models using the supplied auth.
func FetchAntigravityModels(ctx context.Context, auth *cliproxyauth.Auth, cfg *config.Config) []*registry.ModelInfo {
	exec := &AntigravityExecutor{cfg: cfg}
	token, updatedAuth, errToken := exec.ensureAccessToken(ctx, auth)
	if errToken != nil || token == "" {
		return nil
	}
	if updatedAuth != nil {
		auth = updatedAuth
	}

	baseURLs := antigravityBaseURLFallbackOrder(auth)
	httpClient := newAntigravityHTTPClient(ctx, cfg, auth, 0)
	
	for idx, baseURL := range baseURLs {
		modelsURL := baseURL + antigravityModelsPath

		var payload []byte
		if auth != nil && auth.Metadata != nil {
			if pid, ok := auth.Metadata["project_id"].(string); ok && strings.TrimSpace(pid) != "" {
				payload = []byte(fmt.Sprintf(`{"project": "%s"}`, strings.TrimSpace(pid)))
			}
		}
		if len(payload) == 0 {
			payload = []byte(`{}`)
		}

		httpReq, errReq := http.NewRequestWithContext(ctx, http.MethodPost, modelsURL, bytes.NewReader(payload))
		if errReq != nil {
			return nil
		}
		httpReq.Close = true
		httpReq.Header.Set("Content-Type", "application/json")
		httpReq.Header.Set("Authorization", "Bearer "+token)
		httpReq.Header.Set("User-Agent", resolveUserAgent(auth))
		httpReq.Header.Del("X-Forwarded-For")
		httpReq.Header.Del("X-Forwarded-Host")
		httpReq.Header.Del("X-Forwarded-Proto")
		httpReq.Header.Del("X-Forwarded-Port")
		httpReq.Header.Del("X-Real-IP")
		httpReq.Header.Del("Forwarded")
		httpReq.Header.Del("Via")
		if host := resolveHost(baseURL); host != "" {
			httpReq.Host = host
		}

		httpResp, errDo := httpClient.Do(httpReq)
		if errDo != nil {
			if errors.Is(errDo, context.Canceled) || errors.Is(errDo, context.DeadlineExceeded) {
				return nil
			}
			if idx+1 < len(baseURLs) {
				log.Debugf("antigravity executor: models request error on base url %s, retrying with fallback base url: %s", baseURL, baseURLs[idx+1])
				continue
			}
			log.Errorf("antigravity executor: models request failed: %v", errDo)
			return nil
		}

		bodyBytes, errRead := io.ReadAll(httpResp.Body)
		if errClose := httpResp.Body.Close(); errClose != nil {
			log.Errorf("antigravity executor: close response body error: %v", errClose)
		}
		if errRead != nil {
			if idx+1 < len(baseURLs) {
				log.Debugf("antigravity executor: models read error on base url %s, retrying with fallback base url: %s", baseURL, baseURLs[idx+1])
				continue
			}
			log.Errorf("antigravity executor: models read body failed: %v", errRead)
			return nil
		}
		if httpResp.StatusCode < http.StatusOK || httpResp.StatusCode >= http.StatusMultipleChoices {
			if httpResp.StatusCode == http.StatusTooManyRequests && idx+1 < len(baseURLs) {
				log.Debugf("antigravity executor: models request rate limited on base url %s, retrying with fallback base url: %s", baseURL, baseURLs[idx+1])
				continue
			}
			log.Errorf("antigravity executor: models request error status %d: %s", httpResp.StatusCode, string(bodyBytes))
			return nil
		}

		result := gjson.GetBytes(bodyBytes, "models")
		if !result.Exists() {
			return nil
		}

		now := time.Now().Unix()
		modelConfig := registry.GetAntigravityModelConfig()
		models := make([]*registry.ModelInfo, 0, len(result.Map()))
		for originalName, modelData := range result.Map() {
			modelID := strings.TrimSpace(originalName)
			if modelID == "" {
				continue
			}
			switch modelID {
			case "chat_20706", "chat_23310", "gemini-2.5-flash-thinking", "gemini-3-pro-low", "gemini-2.5-pro":
				continue
			}
			modelCfg := modelConfig[modelID]

			// Extract displayName from upstream response, fallback to modelID
			displayName := modelData.Get("displayName").String()
			if displayName == "" {
				displayName = modelID
			}

			modelInfo := &registry.ModelInfo{
				ID:          modelID,
				Name:        modelID,
				Description: displayName,
				DisplayName: displayName,
				Version:     modelID,
				Object:      "model",
				Created:     now,
				OwnedBy:     antigravityAuthType,
				Type:        antigravityAuthType,
			}
			// Look up Thinking support from static config using upstream model name.
			if modelCfg != nil {
				if modelCfg.Thinking != nil {
					modelInfo.Thinking = modelCfg.Thinking
				}
				if modelCfg.MaxCompletionTokens > 0 {
					modelInfo.MaxCompletionTokens = modelCfg.MaxCompletionTokens
				}
			}
			models = append(models, modelInfo)
		}
		return models
	}
	return nil
}

func (e *AntigravityExecutor) ensureAccessToken(ctx context.Context, auth *cliproxyauth.Auth) (string, *cliproxyauth.Auth, error) {
	if auth == nil {
		return "", nil, statusErr{code: http.StatusUnauthorized, msg: "missing auth"}
	}
	accessToken := metaStringValue(auth.Metadata, "access_token")
	expiry := tokenExpiry(auth.Metadata)
	if accessToken != "" && expiry.After(time.Now().Add(refreshSkew)) {
		return accessToken, nil, nil
	}
	refreshCtx := context.Background()
	if ctx != nil {
		if rt, ok := ctx.Value("cliproxy.roundtripper").(http.RoundTripper); ok && rt != nil {
			refreshCtx = context.WithValue(refreshCtx, "cliproxy.roundtripper", rt)
		}
	}
	updated, errRefresh := e.refreshToken(refreshCtx, auth.Clone())
	if errRefresh != nil {
		return "", nil, errRefresh
	}
	return metaStringValue(updated.Metadata, "access_token"), updated, nil
}

func (e *AntigravityExecutor) refreshToken(ctx context.Context, auth *cliproxyauth.Auth) (*cliproxyauth.Auth, error) {
	if auth == nil {
		return nil, statusErr{code: http.StatusUnauthorized, msg: "missing auth"}
	}
	refreshToken := metaStringValue(auth.Metadata, "refresh_token")
	if refreshToken == "" {
		return auth, statusErr{code: http.StatusUnauthorized, msg: "missing refresh token"}
	}

	form := url.Values{}
	form.Set("client_id", antigravityClientID)
	form.Set("client_secret", antigravityClientSecret)
	form.Set("grant_type", "refresh_token")
	form.Set("refresh_token", refreshToken)

	httpReq, errReq := http.NewRequestWithContext(ctx, http.MethodPost, "https://oauth2.googleapis.com/token", strings.NewReader(form.Encode()))
	if errReq != nil {
		return auth, errReq
	}
	httpReq.Header.Set("Host", "oauth2.googleapis.com")
	httpReq.Header.Set("User-Agent", defaultAntigravityAgent)
	httpReq.Header.Set("Content-Type", "application/x-www-form-urlencoded")

	httpClient := newAntigravityHTTPClient(ctx, e.cfg, auth, 0)
	httpResp, errDo := httpClient.Do(httpReq)
	if errDo != nil {
		return auth, errDo
	}
	defer func() {
		if errClose := httpResp.Body.Close(); errClose != nil {
			log.Errorf("antigravity executor: close response body error: %v", errClose)
		}
	}()

	bodyBytes, errRead := io.ReadAll(httpResp.Body)
	if errRead != nil {
		return auth, errRead
	}

	if httpResp.StatusCode < http.StatusOK || httpResp.StatusCode >= http.StatusMultipleChoices {
		sErr := statusErr{code: httpResp.StatusCode, msg: string(bodyBytes)}
		if httpResp.StatusCode == http.StatusTooManyRequests {
			if retryAfter, parseErr := parseRetryDelay(bodyBytes); parseErr == nil && retryAfter != nil {
				sErr.retryAfter = retryAfter
			}
		}
		return auth, sErr
	}

	var tokenResp struct {
		AccessToken  string `json:"access_token"`
		RefreshToken string `json:"refresh_token"`
		ExpiresIn    int64  `json:"expires_in"`
		TokenType    string `json:"token_type"`
	}
	if errUnmarshal := json.Unmarshal(bodyBytes, &tokenResp); errUnmarshal != nil {
		return auth, errUnmarshal
	}

	if auth.Metadata == nil {
		auth.Metadata = make(map[string]any)
	}
	auth.Metadata["access_token"] = tokenResp.AccessToken
	if tokenResp.RefreshToken != "" {
		auth.Metadata["refresh_token"] = tokenResp.RefreshToken
	}
	auth.Metadata["expires_in"] = tokenResp.ExpiresIn
	now := time.Now()
	auth.Metadata["timestamp"] = now.UnixMilli()
	auth.Metadata["expired"] = now.Add(time.Duration(tokenResp.ExpiresIn) * time.Second).Format(time.RFC3339)
	auth.Metadata["type"] = antigravityAuthType
	if errProject := e.ensureAntigravityProjectID(ctx, auth, tokenResp.AccessToken); errProject != nil {
		log.Warnf("antigravity executor: ensure project id failed: %v", errProject)
	}
	return auth, nil
}

func (e *AntigravityExecutor) ensureAntigravityProjectID(ctx context.Context, auth *cliproxyauth.Auth, accessToken string) error {
	if auth == nil {
		return nil
	}

	if auth.Metadata["project_id"] != nil {
		return nil
	}

	token := strings.TrimSpace(accessToken)
	if token == "" {
		token = metaStringValue(auth.Metadata, "access_token")
	}
	if token == "" {
		return nil
	}

	httpClient := newAntigravityHTTPClient(ctx, e.cfg, auth, 0)
	projectID, errFetch := sdkAuth.FetchAntigravityProjectID(ctx, token, httpClient)
	if errFetch != nil {
		return errFetch
	}
	if strings.TrimSpace(projectID) == "" {
		return nil
	}
	if auth.Metadata == nil {
		auth.Metadata = make(map[string]any)
	}
	auth.Metadata["project_id"] = strings.TrimSpace(projectID)

	return nil
}

func (e *AntigravityExecutor) buildRequest(ctx context.Context, auth *cliproxyauth.Auth, token, modelName string, payload []byte, stream bool, alt, baseURL string) (*http.Request, error) {
	if token == "" {
		return nil, statusErr{code: http.StatusUnauthorized, msg: "missing access token"}
	}

	base := strings.TrimSuffix(baseURL, "/")
	if base == "" {
		base = buildBaseURL(auth)
	}
	path := antigravityGeneratePath
	if stream {
		path = antigravityStreamPath
	}
	var requestURL strings.Builder
	requestURL.WriteString(base)
	requestURL.WriteString(path)
	if stream {
		if alt != "" {
			requestURL.WriteString("?$alt=")
			requestURL.WriteString(url.QueryEscape(alt))
		} else {
			requestURL.WriteString("?alt=sse")
		}
	} else if alt != "" {
		requestURL.WriteString("?$alt=")
		requestURL.WriteString(url.QueryEscape(alt))
	}

	// Extract project_id from auth metadata if available
	projectID := ""
	if auth != nil && auth.Metadata != nil {
		if pid, ok := auth.Metadata["project_id"].(string); ok {
			projectID = strings.TrimSpace(pid)
		}
	}
	payload = geminiToAntigravity(modelName, payload, projectID)
	payload, _ = sjson.SetBytes(payload, "model", modelName)

	useAntigravitySchema := strings.Contains(modelName, "claude") || strings.Contains(modelName, "gemini-3-pro-high")
	payloadStr := string(payload)
	paths := make([]string, 0)
	util.Walk(gjson.Parse(payloadStr), "", "parametersJsonSchema", &paths)
	for _, p := range paths {
		payloadStr, _ = util.RenameKey(payloadStr, p, p[:len(p)-len("parametersJsonSchema")]+"parameters")
	}

	if useAntigravitySchema {
		payloadStr = util.CleanJSONSchemaForAntigravity(payloadStr)
	} else {
		payloadStr = util.CleanJSONSchemaForGemini(payloadStr)
	}

	if useAntigravitySchema {
		systemInstructionPartsResult := gjson.Get(payloadStr, "request.systemInstruction.parts")
		payloadStr, _ = sjson.Set(payloadStr, "request.systemInstruction.role", "user")
		payloadStr, _ = sjson.Set(payloadStr, "request.systemInstruction.parts.0.text", systemInstruction)
		payloadStr, _ = sjson.Set(payloadStr, "request.systemInstruction.parts.1.text", fmt.Sprintf("Please ignore following [ignore]%s[/ignore]", systemInstruction))

		if systemInstructionPartsResult.Exists() && systemInstructionPartsResult.IsArray() {
			for _, partResult := range systemInstructionPartsResult.Array() {
				payloadStr, _ = sjson.SetRaw(payloadStr, "request.systemInstruction.parts.-1", partResult.Raw)
			}
		}
	}

	if strings.Contains(modelName, "claude") {
		payloadStr, _ = sjson.Set(payloadStr, "request.toolConfig.functionCallingConfig.mode", "VALIDATED")
	} else {
		payloadStr, _ = sjson.Delete(payloadStr, "request.generationConfig.maxOutputTokens")
	}

	httpReq, errReq := http.NewRequestWithContext(ctx, http.MethodPost, requestURL.String(), strings.NewReader(payloadStr))
	if errReq != nil {
		return nil, errReq
	}
	httpReq.Close = true
	httpReq.Header.Set("Content-Type", "application/json")
	httpReq.Header.Set("Authorization", "Bearer "+token)
	httpReq.Header.Set("User-Agent", resolveUserAgent(auth))
	scrubProxyAndFingerprintHeaders(httpReq)
	if host := resolveHost(base); host != "" {
		httpReq.Host = host
	}

	var authID, authLabel, authType, authValue string
	if auth != nil {
		authID = auth.ID
		authLabel = auth.Label
		authType, authValue = auth.AccountInfo()
	}
	var payloadLog []byte
	if e.cfg != nil && e.cfg.RequestLog {
		payloadLog = []byte(payloadStr)
	}
	recordAPIRequest(ctx, e.cfg, upstreamRequestLog{
		URL:       requestURL.String(),
		Method:    http.MethodPost,
		Headers:   httpReq.Header.Clone(),
		Body:      payloadLog,
		Provider:  e.Identifier(),
		AuthID:    authID,
		AuthLabel: authLabel,
		AuthType:  authType,
		AuthValue: authValue,
	})

	return httpReq, nil
}

func tokenExpiry(metadata map[string]any) time.Time {
	if metadata == nil {
		return time.Time{}
	}
	if expStr, ok := metadata["expired"].(string); ok {
		expStr = strings.TrimSpace(expStr)
		if expStr != "" {
			if parsed, errParse := time.Parse(time.RFC3339, expStr); errParse == nil {
				return parsed
			}
		}
	}
	expiresIn, hasExpires := int64Value(metadata["expires_in"])
	tsMs, hasTimestamp := int64Value(metadata["timestamp"])
	if hasExpires && hasTimestamp {
		return time.Unix(0, tsMs*int64(time.Millisecond)).Add(time.Duration(expiresIn) * time.Second)
	}
	return time.Time{}
}

func metaStringValue(metadata map[string]any, key string) string {
	if metadata == nil {
		return ""
	}
	if v, ok := metadata[key]; ok {
		switch typed := v.(type) {
		case string:
			return strings.TrimSpace(typed)
		case []byte:
			return strings.TrimSpace(string(typed))
		}
	}
	return ""
}

func int64Value(value any) (int64, bool) {
	switch typed := value.(type) {
	case int:
		return int64(typed), true
	case int64:
		return typed, true
	case float64:
		return int64(typed), true
	case json.Number:
		if i, errParse := typed.Int64(); errParse == nil {
			return i, true
		}
	case string:
		if strings.TrimSpace(typed) == "" {
			return 0, false
		}
		if i, errParse := strconv.ParseInt(strings.TrimSpace(typed), 10, 64); errParse == nil {
			return i, true
		}
	}
	return 0, false
}

func buildBaseURL(auth *cliproxyauth.Auth) string {
	if baseURLs := antigravityBaseURLFallbackOrder(auth); len(baseURLs) > 0 {
		return baseURLs[0]
	}
	return antigravityBaseURLDaily
}

func resolveHost(base string) string {
	parsed, errParse := url.Parse(base)
	if errParse != nil {
		return ""
	}
	if parsed.Host != "" {
		return parsed.Host
	}
	return strings.TrimPrefix(strings.TrimPrefix(base, "https://"), "http://")
}

func resolveUserAgent(auth *cliproxyauth.Auth) string {
	if auth != nil {
		if auth.Attributes != nil {
			if ua := strings.TrimSpace(auth.Attributes["user_agent"]); ua != "" {
				return ua
			}
		}
		if auth.Metadata != nil {
			if ua, ok := auth.Metadata["user_agent"].(string); ok && strings.TrimSpace(ua) != "" {
				return strings.TrimSpace(ua)
			}
		}
	}
	return defaultAntigravityAgent
}

func antigravityRetryAttempts(auth *cliproxyauth.Auth, cfg *config.Config) int {
	retry := 0
	if cfg != nil {
		retry = cfg.RequestRetry
	}
	if auth != nil {
		if override, ok := auth.RequestRetryOverride(); ok {
			retry = override
		}
	}
	if retry < 0 {
		retry = 0
	}
	attempts := retry + 1
	if attempts < 1 {
		return 1
	}
	return attempts
}

func antigravityShouldRetryNoCapacity(statusCode int, body []byte) bool {
	if statusCode != http.StatusServiceUnavailable {
		return false
	}
	if len(body) == 0 {
		return false
	}
	msg := strings.ToLower(string(body))
	return strings.Contains(msg, "no capacity available")
}

func antigravityNoCapacityRetryDelay(attempt int) time.Duration {
	if attempt < 0 {
		attempt = 0
	}
	delay := time.Duration(attempt+1) * 250 * time.Millisecond
	if delay > 2*time.Second {
		delay = 2 * time.Second
	}
	return delay
}

func antigravityWait(ctx context.Context, wait time.Duration) error {
	if wait <= 0 {
		return nil
	}
	timer := time.NewTimer(wait)
	defer timer.Stop()
	select {
	case <-ctx.Done():
		return ctx.Err()
	case <-timer.C:
		return nil
	}
}

func antigravityBaseURLFallbackOrder(auth *cliproxyauth.Auth) []string {
	if base := resolveCustomAntigravityBaseURL(auth); base != "" {
		return []string{base}
	}
	return []string{
		antigravityBaseURLDaily,
		antigravitySandboxBaseURLDaily,
		// antigravityBaseURLProd,
	}
}

func resolveCustomAntigravityBaseURL(auth *cliproxyauth.Auth) string {
	if auth == nil {
		return ""
	}
	if auth.Attributes != nil {
		if v := strings.TrimSpace(auth.Attributes["base_url"]); v != "" {
			return strings.TrimSuffix(v, "/")
		}
	}
	if auth.Metadata != nil {
		if v, ok := auth.Metadata["base_url"].(string); ok {
			v = strings.TrimSpace(v)
			if v != "" {
				return strings.TrimSuffix(v, "/")
			}
		}
	}
	return ""
}

func geminiToAntigravity(modelName string, payload []byte, projectID string) []byte {
	template, _ := sjson.Set(string(payload), "model", modelName)
	template, _ = sjson.Set(template, "userAgent", "antigravity")
	template, _ = sjson.Set(template, "requestType", "agent")

	// Use real project ID from auth if available, otherwise generate random (legacy fallback)
	if projectID != "" {
		template, _ = sjson.Set(template, "project", projectID)
	} else {
		template, _ = sjson.Set(template, "project", generateProjectID())
	}
	template, _ = sjson.Set(template, "requestId", generateRequestID())
	template, _ = sjson.Set(template, "request.sessionId", generateStableSessionID(payload))

	template, _ = sjson.Delete(template, "request.safetySettings")
	if toolConfig := gjson.Get(template, "toolConfig"); toolConfig.Exists() && !gjson.Get(template, "request.toolConfig").Exists() {
		template, _ = sjson.SetRaw(template, "request.toolConfig", toolConfig.Raw)
		template, _ = sjson.Delete(template, "toolConfig")
	}
	return []byte(template)
}

func generateRequestID() string {
	return "agent-" + uuid.NewString()
}

func generateSessionID() string {
	randSourceMutex.Lock()
	n := randSource.Int63n(9_000_000_000_000_000_000)
	randSourceMutex.Unlock()
	return "-" + strconv.FormatInt(n, 10)
}

func generateStableSessionID(payload []byte) string {
	contents := gjson.GetBytes(payload, "request.contents")
	if contents.IsArray() {
		for _, content := range contents.Array() {
			if content.Get("role").String() == "user" {
				text := content.Get("parts.0.text").String()
				if text != "" {
					h := sha256.Sum256([]byte(text))
					n := int64(binary.BigEndian.Uint64(h[:8])) & 0x7FFFFFFFFFFFFFFF
					return "-" + strconv.FormatInt(n, 10)
				}
			}
		}
	}
	return generateSessionID()
}

func generateProjectID() string {
	adjectives := []string{"useful", "bright", "swift", "calm", "bold"}
	nouns := []string{"fuze", "wave", "spark", "flow", "core"}
	randSourceMutex.Lock()
	adj := adjectives[randSource.Intn(len(adjectives))]
	noun := nouns[randSource.Intn(len(nouns))]
	randSourceMutex.Unlock()
	randomPart := strings.ToLower(uuid.NewString())[:5]
	return adj + "-" + noun + "-" + randomPart
}