"""export.py — POST /api/v1/export/doc"""

from pathlib import Path

from fastapi import APIRouter, Depends
from sqlalchemy.ext.asyncio import AsyncSession

from app.api.v1 import ok
from app.config import settings
from app.core.dependencies import get_db
from app.core.exceptions import ExportError
from app.schemas.export import ExportDocRequest, ExportDocResponse
from app.services.content_db import ContentDB
from app.services.document_service import DocumentService
from app.services.export_record_service import ExportRecordService
from app.services.export_service import (
    build_style_map,
    load_style_file,
    blocks_to_docx_bytes,
    _make_filename,
    update_document_fields,
)
from app.services.storage_monitor import check_quota

router = APIRouter(tags=["Export"])


@router.post("/export/doc", summary="导出 .doc 文件")
async def export_document(
    body: ExportDocRequest,
    db: AsyncSession = Depends(get_db),
) -> dict:
    doc_svc = DocumentService(db)
    rec_svc = ExportRecordService(db)

    # 1. 读取文档
    doc = await doc_svc.get_document(body.document_id)
    user_id = doc.created_by or "default-user"

    # 2. 检查是否有最新记录可复用
    latest = await rec_svc.get_latest_record(body.document_id)
    if latest and doc.updated_at <= latest.created_at:
        # 文档未更新，直接复用已有记录
        warning = check_quota(user_id)
        return ok(ExportDocResponse(
            record_id=latest.id,
            download_url=latest.download_url,
            file_name=latest.file_name,
            style_id=latest.style_id,
            warning=warning,
        ).model_dump(by_alias=True))

    # 3. 加载样式
    style_data = load_style_file(body.style_id)
    style_map = build_style_map(style_data)
    actual_style_id = body.style_id or "default"

    # 4. 从 SQLite 读取 blocks 并生成 .doc 字节流
    try:
        with ContentDB(doc.content_db_path) as content_db:
            blocks = content_db.get_blocks()
        
        # Blocks → Word
        doc_bytes = blocks_to_docx_bytes(blocks, style_map, style_data)
    except Exception as exc:
        raise ExportError(f"文档转换失败: {exc}") from exc

    # 5. 写入文件：./tmp/{user_id}/{YYYY-MM-DD}/{name}.doc
    from datetime import date
    file_stem = _make_filename(blocks)
    file_name = f"{file_stem}.doc"
    today = date.today().strftime("%Y-%m-%d")
    user_dir = Path(settings.temp_dir) / user_id / today
    user_dir.mkdir(parents=True, exist_ok=True)
    file_path = user_dir / file_name

    try:
        file_path.write_bytes(doc_bytes)
    except OSError as exc:
        raise ExportError(f"文件写入失败: {exc}") from exc

    # 5.5. 如果文档包含 TOC，使用 WPS/Word 更新域（目录和页码）
    has_toc = any(block.get('type') == 'toc' for block in blocks)
    if has_toc:
        update_success = update_document_fields(str(file_path))
        if update_success:
            # 域更新成功后，重新读取文件大小（可能略有变化）
            file_size = file_path.stat().st_size
    
    # 获取最终文件大小
    file_size = file_path.stat().st_size

    # 6. 写入数据库记录（先占位 download_url，再回写）
    record = await rec_svc.create_record(
        user_id=user_id,
        file_name=file_name,
        file_path=str(file_path),
        file_size=file_size,
        download_url="",
        document_id=doc.id,
        style_id=actual_style_id,
    )
    download_url = (
        f"{settings.base_url.rstrip('/')}/api/v1/export/records/{record.id}/download"
        f"?userId={user_id}"
    )
    record.download_url = download_url
    await db.commit()

    # 7. 配额检查
    warning = check_quota(user_id)

    return ok(ExportDocResponse(
        record_id=record.id,
        download_url=download_url,
        file_name=file_name,
        style_id=actual_style_id,
        warning=warning,
    ).model_dump(by_alias=True))