from __future__ import annotations

import logging
from pathlib import Path

from django.conf import settings
from openpyxl import Workbook

from review_agent.models import ExportedSummaryFile, FileSummaryBatch


logger = logging.getLogger("review_agent.file_summary.export_excel")


def _exports_dir(batch: FileSummaryBatch) -> Path:
    root = Path(batch.work_dir) if batch.work_dir else Path(settings.MEDIA_ROOT) / "file_summary" / batch.batch_no
    export_dir = root / "exports"
    export_dir.mkdir(parents=True, exist_ok=True)
    return export_dir


def generate_excel_export(batch: FileSummaryBatch) -> ExportedSummaryFile:
    logger.info("Excel export generation started", extra={"batch_id": batch.pk})
    workbook = Workbook()
    summary = workbook.active
    summary.title = "汇总信息"
    summary.append(["批次号", batch.batch_no])
    summary.append(["产品名称", batch.product_name or "-"])
    summary.append(["文件总数", batch.total_files])
    summary.append(["统计成功", batch.success_files])
    summary.append(["统计失败", batch.failed_files])
    summary.append(["不支持", batch.unsupported_files])
    summary.append(["不确定", batch.uncertain_files])
    summary.append(["总页数", batch.total_pages])

    detail = workbook.create_sheet("文件明细")
    detail.append(["序号", "目录层级", "文件名", "类型", "页数", "路径", "状态", "重试次数", "异常说明"])
    for item in batch.items.order_by("file_index"):
        detail.append(
            [
                item.file_index,
                item.directory_level,
                item.file_name,
                item.file_type,
                item.page_count,
                item.relative_path,
                item.statistics_status,
                item.retry_count,
                item.error_message,
            ]
        )

    path = _exports_dir(batch) / f"{batch.batch_no}-summary.xlsx"
    workbook.save(path)
    exported = ExportedSummaryFile.objects.create(
        batch=batch,
        export_type=ExportedSummaryFile.ExportType.EXCEL,
        file_name=path.name,
        storage_path=str(path),
    )
    logger.info(
        "Excel export generation finished",
        extra={"batch_id": batch.pk, "export_id": exported.pk, "path": str(path)},
    )
    return exported