from __future__ import annotations

from datetime import datetime
from typing import ClassVar

from pydantic import BaseModel, Field, validator

from app.keyboards.admin import BROADCAST_BUTTONS, DEFAULT_BROADCAST_BUTTONS


class BroadcastMedia(BaseModel):
    type: str = Field(pattern=r'^(photo|video|document)$')
    file_id: str
    caption: str | None = None


class BroadcastCreateRequest(BaseModel):
    target: str
    message_text: str = Field(..., min_length=1, max_length=4000)
    selected_buttons: list[str] = Field(default_factory=lambda: list(DEFAULT_BROADCAST_BUTTONS))
    media: BroadcastMedia | None = None

    _ALLOWED_TARGETS: ClassVar[set[str]] = {
        'all',
        'active',
        'trial',
        'no',
        'expiring',
        'expired',
        'active_zero',
        'trial_zero',
        'zero',
    }
    _CUSTOM_TARGETS: ClassVar[set[str]] = {
        'today',
        'week',
        'month',
        'active_today',
        'inactive_week',
        'inactive_month',
        'referrals',
        'direct',
    }
    _TARGET_ALIASES: ClassVar[dict[str, str]] = {
        'no_sub': 'no',
    }

    @validator('target')
    def validate_target(cls, value: str) -> str:
        normalized = value.strip().lower()
        normalized = cls._TARGET_ALIASES.get(normalized, normalized)

        if normalized in cls._ALLOWED_TARGETS:
            return normalized

        if normalized.startswith('custom_'):
            criteria = normalized[len('custom_') :]
            if criteria in cls._CUSTOM_TARGETS:
                return normalized

        raise ValueError('Unsupported target value')

    @validator('selected_buttons', pre=True)
    def validate_selected_buttons(cls, value):
        if value is None:
            return []
        if not isinstance(value, (list, tuple)):
            raise TypeError('selected_buttons must be an array')

        seen = set()
        ordered: list[str] = []
        for raw_button in value:
            button = str(raw_button).strip()
            if not button:
                continue
            if button not in BROADCAST_BUTTONS:
                raise ValueError(f"Unsupported button '{button}'")
            if button in seen:
                continue
            ordered.append(button)
            seen.add(button)
        return ordered


class BroadcastResponse(BaseModel):
    id: int
    target_type: str
    message_text: str
    has_media: bool
    media_type: str | None = None
    media_file_id: str | None = None
    media_caption: str | None = None
    total_count: int
    sent_count: int
    failed_count: int
    status: str
    admin_id: int | None = None
    admin_name: str | None = None
    created_at: datetime
    completed_at: datetime | None = None


class BroadcastListResponse(BaseModel):
    items: list[BroadcastResponse]
    total: int
    limit: int
    offset: int