#!/usr/bin/env python3
"""Generate Flatpak source entries for Cargo dependencies from Cargo.lock.

Usage:
    python3 build-aux/flatpak-cargo-generator.py [Cargo.lock] \
        -o build-aux/cargo-sources.json
"""

import json
import sys

try:
    import tomllib
except ImportError:
    try:
        import tomli as tomllib  # pip install tomli
    except ImportError:
        print("Error: requires Python 3.11+ or the 'tomli' package", file=sys.stderr)
        sys.exit(1)

CRATES_IO_DL = "https://static.crates.io/crates"
REGISTRY_SOURCE = "registry+https://github.com/rust-lang/crates.io-index"


def main() -> None:
    # Parse arguments
    lockfile = "Cargo.lock"
    output_file = None

    args = sys.argv[1:]
    i = 0
    while i < len(args):
        if args[i] == "-o" and i + 1 < len(args):
            output_file = args[i + 1]
            i += 2
        else:
            lockfile = args[i]
            i += 1

    with open(lockfile, "rb") as f:
        lock = tomllib.load(f)

    sources = []
    checksums = {}

    for pkg in lock.get("package", []):
        name = pkg["name"]
        version = pkg["version"]
        source = pkg.get("source", "")
        checksum = pkg.get("checksum")

        # Only vendor packages from crates.io (they have a checksum)
        if source == REGISTRY_SOURCE and checksum:
            dest = f"cargo-vendor/{name}-{version}"
            sources.append(
                {
                    "type": "archive",
                    "archive-type": "tar-gzip",
                    "url": f"{CRATES_IO_DL}/{name}/{version}/download",
                    "sha256": checksum,
                    "dest": dest,
                }
            )
            checksums[f"{name}-{version}"] = checksum

    output = json.dumps(sources, indent=2)

    if output_file:
        with open(output_file, "w") as f:
            f.write(output)
        # Also write checksums file
        checksums_file = output_file.replace(".json", "-checksums.json")
        with open(checksums_file, "w") as f:
            json.dump(checksums, f)
        print(f"Generated {output_file} and {checksums_file}")
    else:
        print(output)


if __name__ == "__main__":
    main()