from __future__ import annotations

import logging
from pathlib import Path

from django.conf import settings

from review_agent.models import ExportedSummaryFile, FileSummaryBatch


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


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 build_summary_table(batch: FileSummaryBatch) -> str:
    lines = [
        "| 序号 | 目录层级 | 文件名 | 类型 | 页数 | 状态 | 异常说明 |",
        "| --- | --- | --- | --- | --- | --- | --- |",
    ]
    for item in batch.items.order_by("file_index"):
        lines.append(
            "| {index} | {directory} | {name} | {file_type} | {pages} | {status} | {error} |".format(
                index=item.file_index,
                directory=item.directory_level or "-",
                name=item.file_name,
                file_type=item.file_type,
                pages=item.page_count if item.page_count is not None else "-",
                status=item.statistics_status,
                error=item.error_message or "-",
            )
        )
    return "\n".join(lines)


def build_markdown_report(batch: FileSummaryBatch) -> str:
    return "\n\n".join(
        [
            f"# 文件目录与页数汇总报告\n\n批次号：{batch.batch_no}",
            (
                "## 汇总信息\n\n"
                f"- 产品名称：{batch.product_name or '-'}\n"
                f"- 文件总数：{batch.total_files}\n"
                f"- 统计成功：{batch.success_files}\n"
                f"- 统计失败：{batch.failed_files}\n"
                f"- 不支持：{batch.unsupported_files}\n"
                f"- 不确定：{batch.uncertain_files}\n"
                f"- 总页数：{batch.total_pages}"
            ),
            "## 文件明细\n\n" + build_summary_table(batch),
            "## 处理说明\n\n单文件失败不会阻断批次，失败与不确定文件已在明细中标注。",
        ]
    )


def generate_markdown_report(batch: FileSummaryBatch) -> tuple[ExportedSummaryFile, str]:
    logger.info("Markdown report generation started", extra={"batch_id": batch.pk})
    content = build_markdown_report(batch)
    path = _exports_dir(batch) / f"{batch.batch_no}-summary.md"
    path.write_text(content, encoding="utf-8")
    exported = ExportedSummaryFile.objects.create(
        batch=batch,
        workflow_type="file_summary",
        workflow_batch_id=batch.pk,
        export_category="summary",
        export_type=ExportedSummaryFile.ExportType.MARKDOWN,
        file_name=path.name,
        storage_path=str(path),
    )
    logger.info(
        "Markdown report generation finished",
        extra={"batch_id": batch.pk, "export_id": exported.pk, "path": str(path)},
    )
    return exported, build_summary_table(batch)