#!/usr/bin/env python3
"""Validate the structure and evidence links of the AI distillate."""

from __future__ import annotations

import re
import sys
from pathlib import Path


ROOT = Path(__file__).resolve().parent.parent
LEARNINGS = ROOT / "learnings"
REQUIRED_FILES = (
    ROOT / "README.md",
    ROOT / "AGENTS.md",
    ROOT / "TASTE.md",
    LEARNINGS / "README.md",
)
RECORD_NAME = re.compile(
    r"^(?P<date>\d{4}-\d{2}-\d{2})-(?P<number>\d{3})-"
    r"(?P<slug>[a-z0-9][a-z0-9-]*)\.md$"
)
RECORD_HEADINGS = (
    "# ",
    "## 原始输入",
    "## 内容蒸馏",
    "## Taste 信号",
    "### 明确偏好",
    "### 推断信号",
    "### 领域知识",
    "## 边界与反例",
    "## 可执行影响",
    "## 画像更新",
)
PROFILE_LABELS = ("状态", "适用范围", "规则", "证据", "边界")
PROFILE_STATUSES = {"确认", "暂定", "有条件", "已取代"}
EVIDENCE_LINK = re.compile(r"\]\((learnings/[^)#]+\.md)(?:#[^)]+)?\)")


def parse_front_matter(text: str) -> dict[str, str] | None:
    if not text.startswith("---\n"):
        return None
    closing = text.find("\n---\n", 4)
    if closing == -1:
        return None

    fields: dict[str, str] = {}
    for line in text[4:closing].splitlines():
        if ":" in line and not line.startswith((" ", "\t")):
            key, value = line.split(":", 1)
            fields[key.strip()] = value.strip()
    return fields


def validate_record(record: Path) -> list[str]:
    errors: list[str] = []
    match = RECORD_NAME.fullmatch(record.name)
    if match is None:
        return [f"{record.relative_to(ROOT)}: 文件名不符合约定"]

    text = record.read_text(encoding="utf-8")
    fields = parse_front_matter(text)
    if fields is None:
        return [f"{record.relative_to(ROOT)}: 缺少完整的 YAML front matter"]

    expected_id = record.name[:14]
    required_fields = {"id", "date", "status", "tags", "sources", "references"}
    missing_fields = sorted(required_fields - fields.keys())
    if missing_fields:
        errors.append(
            f"{record.relative_to(ROOT)}: 缺少字段 {', '.join(missing_fields)}"
        )
    if fields.get("id") != expected_id:
        errors.append(
            f"{record.relative_to(ROOT)}: id 应为 {expected_id}"
        )
    if fields.get("date") != match.group("date"):
        errors.append(
            f"{record.relative_to(ROOT)}: date 应与文件名日期一致"
        )
    if fields.get("status") not in {"distilled", "needs-evidence"}:
        errors.append(
            f"{record.relative_to(ROOT)}: status 必须是 distilled 或 needs-evidence"
        )

    lines = text.splitlines()
    for heading in RECORD_HEADINGS:
        if heading == "# ":
            if not any(line.startswith("# ") for line in lines):
                errors.append(f"{record.relative_to(ROOT)}: 缺少一级标题")
        elif heading not in lines:
            errors.append(f"{record.relative_to(ROOT)}: 缺少标题 {heading}")
    return errors


def validate_profile() -> list[str]:
    profile_path = ROOT / "TASTE.md"
    text = profile_path.read_text(encoding="utf-8")
    marker = "## 当前画像"
    if marker not in text:
        return ["TASTE.md: 缺少‘当前画像’部分"]

    current = text.split(marker, 1)[1].strip()
    placeholder = "尚无通过 `学习：xxx` 沉淀的条目。"
    if current == placeholder:
        return []
    if placeholder in current:
        return ["TASTE.md: 已有画像条目时应删除空画像占位文字"]

    starts = list(re.finditer(r"(?m)^### (.+)$", current))
    if not starts:
        return ["TASTE.md: 当前画像必须使用三级标题组织条目"]

    errors: list[str] = []
    for index, start in enumerate(starts):
        end = starts[index + 1].start() if index + 1 < len(starts) else len(current)
        title = start.group(1)
        entry = current[start.end():end]
        values: dict[str, str] = {}
        for label in PROFILE_LABELS:
            match = re.search(rf"(?m)^- {re.escape(label)}：(.+)$", entry)
            if match is None:
                errors.append(f"TASTE.md / {title}: 缺少‘{label}’")
            else:
                values[label] = match.group(1).strip()
        if "状态" in values and values["状态"] not in PROFILE_STATUSES:
            errors.append(f"TASTE.md / {title}: 状态值无效")
        if "证据" in values and EVIDENCE_LINK.search(values["证据"]) is None:
            errors.append(f"TASTE.md / {title}: 证据必须链接到 learnings/ 记录")
    return errors


def validate_evidence_links() -> list[str]:
    text = (ROOT / "TASTE.md").read_text(encoding="utf-8")
    marker = "## 当前画像"
    if marker in text:
        text = text.split(marker, 1)[1]
    errors: list[str] = []
    for relative_path in EVIDENCE_LINK.findall(text):
        if not (ROOT / relative_path).is_file():
            errors.append(f"TASTE.md: 证据链接不存在：{relative_path}")
    return errors


def main() -> int:
    errors = [
        f"缺少必要文件：{path.relative_to(ROOT)}"
        for path in REQUIRED_FILES
        if not path.is_file()
    ]
    if errors:
        for error in errors:
            print(f"ERROR: {error}", file=sys.stderr)
        return 1

    records = sorted(
        path for path in LEARNINGS.glob("*.md") if path.name != "README.md"
    )
    for record in records:
        errors.extend(validate_record(record))
    errors.extend(validate_profile())
    errors.extend(validate_evidence_links())

    if errors:
        for error in errors:
            print(f"ERROR: {error}", file=sys.stderr)
        return 1

    print(f"OK: {len(records)} learning record(s), profile structure is valid")
    return 0


if __name__ == "__main__":
    raise SystemExit(main())