from __future__ import annotations

from .shared import *

class TaskBriefSeedHistoryMixin:
    @staticmethod
    def _extract_markdown_section_lines(content: str, *, heading: str) -> list[str]:
        target = f"## {heading}".lower()
        lines = content.splitlines()
        in_section = False
        collected: list[str] = []
        for raw in lines:
            line = raw.strip()
            if line.lower().startswith("## "):
                if line.lower() == target:
                    in_section = True
                    continue
                if in_section:
                    break
            if in_section and line:
                collected.append(line)
        return collected

    @staticmethod
    def _extract_markdown_meta_value(content: str, *, key: str) -> str | None:
        prefix = f"- {key}:"
        for raw in content.splitlines():
            line = raw.strip()
            if line.startswith(prefix):
                return line.split(":", 1)[1].strip() or None
        return None

    @classmethod
    def _normalize_generated_at(cls, raw_generated: str | None, fallback: datetime) -> str:
        if not raw_generated:
            return fallback.isoformat()
        for fmt in ("%Y-%m-%d %H:%M:%S %z",):
            try:
                return datetime.strptime(raw_generated, fmt).isoformat()
            except Exception:
                pass
        try:
            return datetime.fromisoformat(raw_generated).isoformat()
        except Exception:
            return raw_generated

    @classmethod
    def _load_seed_history(cls) -> tuple[list[dict[str, Any]], list[dict[str, Any]]]:
        docs_dir = cls._project_root() / "docs/task_briefs"
        if not docs_dir.exists():
            return [], []

        briefs: list[dict[str, Any]] = []
        runs: list[dict[str, Any]] = []
        for file_path in sorted(docs_dir.glob("task_brief_*.md")):
            try:
                content = file_path.read_text(encoding="utf-8")
            except Exception:
                continue
            if not content.strip():
                continue

            stem = "".join(ch for ch in file_path.stem if ch.isalnum() or ch in {"_", "-"})
            brief_id = f"brief_seed_{stem}"[:64]
            run_id = f"run_seed_{stem}"[:64]
            fallback_time = datetime.fromtimestamp(file_path.stat().st_mtime)
            generated_at = cls._normalize_generated_at(
                cls._extract_markdown_meta_value(content, key="Generated At"),
                fallback=fallback_time,
            )

            title = "导入任务包"
            for line in content.splitlines():
                if line.strip().startswith("# "):
                    title = line.strip()[2:].strip() or title
                    break

            changed_section = cls._extract_markdown_section_lines(content, heading="Changed Files")
            changed_files = [line[2:].strip() for line in changed_section if line.startswith("- ") and line[2:].strip()]

            scope_section = cls._extract_markdown_section_lines(content, heading="Scope")
            scope_items = [line[2:].strip() if line.startswith("- ") else line for line in scope_section]
            scope_summary = "；".join([item for item in scope_items if item][:2]).strip()
            if not scope_summary:
                scope_summary = "从 docs/task_briefs 自动导入"

            run = {
                "id": run_id,
                "brief_id": brief_id,
                "title": title,
                "template_id": DEFAULT_TEMPLATE_ID,
                "template_name": DEFAULT_TEMPLATE_NAME,
                "generated_at": generated_at,
                "generated_by": 0,
                "status": "imported",
                "changed_files": changed_files,
                "scope_summary": scope_summary,
            }
            brief = {
                "id": brief_id,
                "title": title,
                "status": "ready",
                "created_at": generated_at,
                "updated_at": generated_at,
                "latest_run_id": run_id,
                "template_id": DEFAULT_TEMPLATE_ID,
                "template_name": DEFAULT_TEMPLATE_NAME,
                "summary": scope_summary,
                "content": content.strip(),
                "changed_files": changed_files,
            }
            runs.append(run)
            briefs.append(brief)
        return briefs, runs