#!/usr/bin/env python3
"""Generate slim README.md from database.json and platform configs.

Detailed documentation lives on the MkDocs site (abdess.github.io/retrobios/).
This script produces a concise landing page with download links and coverage.

Usage:
    python scripts/generate_readme.py [--db database.json] [--platforms-dir platforms/]
"""

from __future__ import annotations

import argparse
import json
import os
import sys
from datetime import datetime, timezone
from pathlib import Path

sys.path.insert(0, os.path.dirname(__file__))
from common import load_database, load_platform_config
from verify import verify_platform

def compute_coverage(platform_name: str, platforms_dir: str, db: dict) -> dict:
    config = load_platform_config(platform_name, platforms_dir)
    result = verify_platform(config, db)
    sc = result.get("status_counts", {})
    ok = sc.get("ok", 0)
    untested = sc.get("untested", 0)
    missing = sc.get("missing", 0)
    total = result["total_files"]
    present = ok + untested
    pct = (present / total * 100) if total > 0 else 0
    return {
        "platform": config.get("platform", platform_name),
        "total": total,
        "verified": ok,
        "untested": untested,
        "missing": missing,
        "present": present,
        "percentage": pct,
        "mode": config.get("verification_mode", "existence"),
        "details": result["details"],
        "config": config,
    }


SITE_URL = "https://abdess.github.io/retrobios/"
RELEASE_URL = "../../releases/latest"


def generate_readme(db: dict, platforms_dir: str) -> str:
    total_files = db.get("total_files", 0)
    total_size = db.get("total_size", 0)
    size_mb = total_size / (1024 * 1024)
    ts = datetime.now(timezone.utc).strftime("%Y-%m-%dT%H:%M:%SZ")

    platform_names = sorted(
        p.stem for p in Path(platforms_dir).glob("*.yml")
        if not p.name.startswith("_")
    )

    coverages = {}
    for name in platform_names:
        try:
            coverages[name] = compute_coverage(name, platforms_dir, db)
        except FileNotFoundError:
            pass

    emulator_count = sum(
        1 for f in Path("emulators").glob("*.yml")
    ) if Path("emulators").exists() else 0

    lines = [
        "# Retrogaming BIOS & Firmware Collection",
        "",
        "Complete, verified collection of BIOS, firmware, and system files for retrogaming emulators.",
        "",
        f"> **{total_files}** files | **{size_mb:.1f} MB** | **{len(coverages)}** platforms | **{emulator_count}** emulator profiles",
        "",
        "## Download",
        "",
        "| Platform | Files | Verification | Pack |",
        "|----------|-------|-------------|------|",
    ]

    for name, cov in sorted(coverages.items(), key=lambda x: x[1]["platform"]):
        lines.append(
            f"| {cov['platform']} | {cov['total']} | {cov['mode']} | "
            f"[Download]({RELEASE_URL}) |"
        )

    lines.extend([
        "",
        "## Coverage",
        "",
        "| Platform | Coverage | Verified | Untested | Missing |",
        "|----------|----------|----------|----------|---------|",
    ])

    for name, cov in sorted(coverages.items(), key=lambda x: x[1]["platform"]):
        pct = f"{cov['percentage']:.1f}%"
        lines.append(
            f"| {cov['platform']} | {cov['present']}/{cov['total']} ({pct}) | "
            f"{cov['verified']} | {cov['untested']} | {cov['missing']} |"
        )

    lines.extend([
        "",
        "## Documentation",
        "",
        f"Full file listings, platform coverage, emulator profiles, and gap analysis: **[{SITE_URL}]({SITE_URL})**",
        "",
        "## Contributing",
        "",
        "See [CONTRIBUTING.md](CONTRIBUTING.md) for guidelines.",
        "",
        "## License",
        "",
        "This repository provides BIOS files for personal backup and archival purposes.",
        "",
        f"*Auto-generated on {ts}*",
    ])

    return "\n".join(lines) + "\n"


def generate_contributing() -> str:
    return """# Contributing to RetroBIOS

## Add a BIOS file

1. Fork this repository
2. Place the file in `bios/Manufacturer/Console/filename`
3. Variants (alternate hashes): `bios/Manufacturer/Console/.variants/`
4. Create a Pull Request - checksums are verified automatically

## File conventions

- Files >50 MB go in GitHub release assets (`large-files` release)
- RPG Maker and ScummVM directories are excluded from deduplication
- See the [documentation site](https://abdess.github.io/retrobios/) for full details
"""


def main():
    parser = argparse.ArgumentParser(description="Generate slim README.md")
    parser.add_argument("--db", default="database.json")
    parser.add_argument("--platforms-dir", default="platforms")
    args = parser.parse_args()

    db = load_database(args.db)

    readme = generate_readme(db, args.platforms_dir)
    with open("README.md", "w") as f:
        f.write(readme)
    print(f"Generated ./README.md")

    contributing = generate_contributing()
    with open("CONTRIBUTING.md", "w") as f:
        f.write(contributing)
    print(f"Generated ./CONTRIBUTING.md")


if __name__ == "__main__":
    main()