#!/usr/bin/env python3
import sys
from datetime import datetime, timezone
from pathlib import Path
from shutil import copy2, copytree
import subprocess

import tomllib

ORDER = ["vendor", "sync_templates", "sync_standards", "install_skills", "format_md"]
SCRIPT_DIR = Path(__file__).resolve().parent
PLAYBOOK_ROOT = SCRIPT_DIR.parent


def usage() -> str:
    return "Usage:\n  python scripts/playbook.py -config <path>\n  python scripts/playbook.py -h"


def load_config(path: Path) -> dict:
    return tomllib.loads(path.read_text(encoding="utf-8"))


def log(message: str) -> None:
    print(message)


def ensure_dir(path: Path) -> None:
    path.mkdir(parents=True, exist_ok=True)


def normalize_langs(raw: object) -> list[str]:
    if raw is None:
        return ["tsl"]
    if isinstance(raw, str):
        langs = [raw]
    else:
        langs = list(raw)
    cleaned: list[str] = []
    for lang in langs:
        item = str(lang).strip()
        if not item:
            continue
        if "/" in item or "\\" in item or ".." in item:
            raise ValueError(f"invalid lang: {item}")
        cleaned.append(item)
    if not cleaned:
        raise ValueError("langs is empty")
    return cleaned


def read_git_commit(root: Path) -> str:
    try:
        result = subprocess.run(
            ["git", "-C", str(root), "rev-parse", "HEAD"],
            capture_output=True,
            text=True,
            check=True,
        )
    except (OSError, subprocess.CalledProcessError):
        return "N/A"
    return result.stdout.strip() or "N/A"


def write_docs_index(dest_prefix: Path, langs: list[str]) -> None:
    lines = [
        "# 文档导航（Docs Index）",
        "",
        f"本快照为裁剪版 Playbook（langs: {','.join(langs)}）。",
        "",
        "## 跨语言（common）",
        "",
        "- 提交信息与版本号：`common/commit_message.md`",
    ]
    for lang in langs:
        if lang == "tsl":
            lines += [
                "",
                "## TSL（tsl）",
                "",
                "- 代码风格：`tsl/code_style.md`",
                "- 命名规范：`tsl/naming.md`",
                "- 语法手册：`tsl/syntax_book/index.md`",
                "- 工具链与验证命令（模板）：`tsl/toolchain.md`",
            ]
        elif lang == "cpp":
            lines += [
                "",
                "## C++（cpp）",
                "",
                "- 代码风格：`cpp/code_style.md`",
                "- 命名规范：`cpp/naming.md`",
                "- 工具链与验证命令（模板）：`cpp/toolchain.md`",
                "- 第三方依赖（Conan）：`cpp/dependencies_conan.md`",
                "- clangd 配置：`cpp/clangd.md`",
            ]
        elif lang == "python":
            lines += [
                "",
                "## Python（python）",
                "",
                "- 代码风格：`python/style_guide.md`",
                "- 工具链：`python/tooling.md`",
                "- 配置清单：`python/configuration.md`",
            ]
        elif lang == "markdown":
            lines += [
                "",
                "## Markdown（markdown）",
                "",
                "- 代码块与行内代码格式：`markdown/index.md`",
            ]
    docs_index = dest_prefix / "docs/index.md"
    ensure_dir(docs_index.parent)
    docs_index.write_text("\n".join(lines) + "\n", encoding="utf-8")


def write_snapshot_readme(dest_prefix: Path, langs: list[str]) -> None:
    lines = [
        "# Playbook（裁剪快照）",
        "",
        f"本目录为从 Playbook vendoring 的裁剪快照（langs: {','.join(langs)}）。",
        "",
        "## 使用",
        "",
        "在目标项目根目录执行：",
        "",
        "```sh",
        "python docs/standards/playbook/scripts/playbook.py -config playbook.toml",
        "```",
        "",
        "配置示例：`docs/standards/playbook/playbook.toml.example`",
        "",
        "文档入口：",
        "",
        "- `docs/standards/playbook/docs/index.md`",
        "- `.agents/index.md`",
    ]
    (dest_prefix / "README.md").write_text("\n".join(lines) + "\n", encoding="utf-8")


def write_source_file(dest_prefix: Path, langs: list[str]) -> None:
    commit = read_git_commit(PLAYBOOK_ROOT)
    timestamp = datetime.now(timezone.utc).strftime("%Y-%m-%dT%H:%M:%SZ")
    lines = [
        "# SOURCE",
        "",
        f"- Source: {PLAYBOOK_ROOT}",
        f"- Commit: {commit}",
        f"- Date: {timestamp}",
        f"- Langs: {','.join(langs)}",
        "- Generated-by: scripts/playbook.py",
    ]
    (dest_prefix / "SOURCE.md").write_text("\n".join(lines) + "\n", encoding="utf-8")


def vendor_action(config: dict, context: dict) -> int:
    try:
        langs = normalize_langs(config.get("langs"))
    except ValueError as exc:
        print(f"ERROR: {exc}", file=sys.stderr)
        return 2

    target_dir = config.get("target_dir", "docs/standards/playbook")
    target_path = Path(target_dir)
    if target_path.is_absolute() or ".." in target_path.parts:
        print(f"ERROR: invalid target_dir: {target_dir}", file=sys.stderr)
        return 2

    project_root: Path = context["project_root"]
    dest_prefix = project_root / target_path
    dest_standards = dest_prefix.parent

    ensure_dir(dest_standards)

    if dest_prefix.exists():
        timestamp = datetime.now().strftime("%Y%m%d%H%M%S")
        backup = dest_standards / f"{dest_prefix.name}.bak.{timestamp}"
        dest_prefix.rename(backup)
        log(f"Backed up existing snapshot -> {backup}")

    ensure_dir(dest_prefix)

    gitattributes_src = PLAYBOOK_ROOT / ".gitattributes"
    if gitattributes_src.is_file():
        copy2(gitattributes_src, dest_prefix / ".gitattributes")

    copytree(PLAYBOOK_ROOT / "scripts", dest_prefix / "scripts")
    copytree(PLAYBOOK_ROOT / "codex", dest_prefix / "codex")
    copy2(PLAYBOOK_ROOT / "SKILLS.md", dest_prefix / "SKILLS.md")

    common_docs = PLAYBOOK_ROOT / "docs/common"
    if common_docs.is_dir():
        copytree(common_docs, dest_prefix / "docs/common")

    rulesets_root = PLAYBOOK_ROOT / "rulesets"
    ensure_dir(dest_prefix / "rulesets")
    if (rulesets_root / "index.md").is_file():
        copy2(rulesets_root / "index.md", dest_prefix / "rulesets/index.md")

    templates_ci = PLAYBOOK_ROOT / "templates/ci"
    if templates_ci.is_dir():
        copytree(templates_ci, dest_prefix / "templates/ci")

    for lang in langs:
        docs_src = PLAYBOOK_ROOT / "docs" / lang
        rules_src = PLAYBOOK_ROOT / "rulesets" / lang
        if not docs_src.is_dir():
            print(f"ERROR: docs not found for lang={lang}", file=sys.stderr)
            return 2
        if not rules_src.is_dir():
            print(f"ERROR: rulesets not found for lang={lang}", file=sys.stderr)
            return 2
        copytree(docs_src, dest_prefix / "docs" / lang)
        copytree(rules_src, dest_prefix / "rulesets" / lang)
        templates_src = PLAYBOOK_ROOT / "templates" / lang
        if templates_src.is_dir():
            copytree(templates_src, dest_prefix / "templates" / lang)

    example_config = PLAYBOOK_ROOT / "playbook.toml.example"
    if example_config.is_file():
        copy2(example_config, dest_prefix / "playbook.toml.example")

    write_docs_index(dest_prefix, langs)
    write_snapshot_readme(dest_prefix, langs)
    write_source_file(dest_prefix, langs)

    log(f"Vendored snapshot -> {dest_prefix}")
    return 0


def run_action(name: str, config: dict, context: dict) -> int:
    if name == "vendor":
        return vendor_action(config, context)
    print(f"[action] {name}")
    return 0


def main(argv: list[str]) -> int:
    if "-h" in argv or "-help" in argv:
        print(usage())
        return 0
    if "-config" not in argv:
        print("ERROR: -config is required.\n" + usage(), file=sys.stderr)
        return 2
    idx = argv.index("-config")
    if idx + 1 >= len(argv) or not argv[idx + 1]:
        print("ERROR: -config requires a path.\n" + usage(), file=sys.stderr)
        return 2

    config_path = Path(argv[idx + 1]).expanduser()
    if not config_path.is_file():
        print(f"ERROR: config not found: {config_path}", file=sys.stderr)
        return 2

    config = load_config(config_path)
    playbook_config = config.get("playbook", {})
    project_root = playbook_config.get("project_root")
    if project_root:
        root = Path(project_root).expanduser()
    else:
        root = config_path.parent
    context = {"project_root": root.resolve(), "config_path": config_path.resolve()}

    for name in ORDER:
        if name in config:
            result = run_action(name, config[name], context)
            if result != 0:
                return result

    return 0


if __name__ == "__main__":
    raise SystemExit(main(sys.argv[1:]))