from __future__ import annotations

from dataclasses import dataclass

from fastapi import HTTPException

from app.enums.celery_queue import CeleryQueue
from app.enums.common import ModuleEventTypeEnum
from app.services.module_async_recovery_service import (
    TASK_MODULE_V2_VIDEO_PROMPT,
    register_module_step_task,
)
from app.services.module_generation_log_service import log_module_error, log_module_event_file
from app.services.llm_billing import (
    LlmBillingContext,
    log_celery_dispatch_failure,
    log_celery_dispatch_start,
    log_celery_dispatch_success,
)
from app.services.module_generation_v2.config import VIDEO_PROMPT_OPTIMIZE, ModuleGenerationV2Config
from app.tasks.celery_app import celery_app
from app.tasks.module_generation_v2_tasks import start_video_prompt_optimize_v2


@dataclass(frozen=True)
class VideoPromptDispatchResult:
    registry_success: bool
    celery_success: bool
    registry_error: str | None = None
    celery_error: str | None = None

    @property
    def recoverable(self) -> bool:
        return self.registry_success or self.celery_success


def ensure_v2_celery_enabled() -> None:
    if celery_app is None:
        raise HTTPException(status_code=503, detail="Celery未启用")


async def dispatch_video_prompt_v2(
    *,
    config: ModuleGenerationV2Config,
    project_id: str,
    step_id: str,
    billing_context: LlmBillingContext,
) -> VideoPromptDispatchResult:
    """注册并投递 V2 视频提词任务。

    Redis 注册成功但 Celery 直投失败时，由周期恢复任务补投；Celery 成功但
    Redis 注册失败时任务仍可正常执行。只有两个通道都失败时由 API 补偿落库为失败。
    """
    log_celery_dispatch_start(billing_context)
    registry_error: Exception | None = None
    try:
        await register_module_step_task(
            module=config.module,
            project_id=project_id,
            step_id=step_id,
            step_code=VIDEO_PROMPT_OPTIMIZE,
            task_name=TASK_MODULE_V2_VIDEO_PROMPT,
        )
    except Exception as exc:
        registry_error = exc
        log_module_error(
            module=config.module,
            event_type=ModuleEventTypeEnum.V2_VIDEO_PROMPT_REGISTRY_FAILED.value,
            project_id=project_id,
            step_id=step_id,
            message="V2 视频提词 Redis 活跃注册失败，将继续尝试 Celery 直投",
            exc=exc,
        )

    celery_error: Exception | None = None
    try:
        start_video_prompt_optimize_v2.apply_async(
            args=[project_id, step_id],
            queue=CeleryQueue.GEN_CHATAPI_CREATE.value,
            countdown=0,
            task_id=f"module-v2-video-prompt:{step_id}",
        )
    except Exception as exc:
        celery_error = exc
        log_module_error(
            module=config.module,
            event_type=ModuleEventTypeEnum.V2_VIDEO_PROMPT_DISPATCH_FAILED.value,
            project_id=project_id,
            step_id=step_id,
            message="V2 视频提词 Celery 投递失败",
            detail={"redis_registry_available": registry_error is None},
            exc=exc,
        )

    result = VideoPromptDispatchResult(
        registry_success=registry_error is None,
        celery_success=celery_error is None,
        registry_error=str(registry_error) if registry_error else None,
        celery_error=str(celery_error) if celery_error else None,
    )
    if result.celery_success:
        log_celery_dispatch_success(billing_context)
        log_module_event_file(
            module=config.module,
            event_type=ModuleEventTypeEnum.V2_VIDEO_PROMPT_DISPATCHED.value,
            project_id=project_id,
            step_id=step_id,
            message="V2 视频提词任务已投递",
            detail={
                "queue": CeleryQueue.GEN_CHATAPI_CREATE.value,
                "redis_registry_available": result.registry_success,
            },
        )
    if not result.celery_success:
        log_celery_dispatch_failure(
            billing_context,
            error=result.celery_error or "Celery direct dispatch failed; waiting for registry recovery",
        )
    return result