#!/usr/bin/env python3
"""Log a git commit event to .zed-hours/commits.jsonl.

This script is normally called by the git post-commit hook.
It can also be run manually for testing.
"""

import json
import os
import subprocess
from datetime import datetime, timezone
from pathlib import Path


def get_project_root() -> Path:
    try:
        root = subprocess.check_output(
            ["git", "rev-parse", "--show-toplevel"],
            cwd=os.environ.get("GIT_DIR", "."),
            text=True,
            stderr=subprocess.DEVNULL,
        ).strip()
        return Path(root).resolve()
    except (subprocess.CalledProcessError, FileNotFoundError):
        pass
    # Fallback 1: script location (<project>/tools/time_tracking/)
    script_project = Path(__file__).resolve().parents[2]
    if (script_project / ".git").exists() or (script_project / ".zed-hours").exists():
        return script_project
    # Fallback 2: current directory
    return Path.cwd().resolve()


def get_last_commit_info(project_root: Path) -> dict:
    try:
        log_format = "%H|%an|%ae|%s|%D"
        out = subprocess.check_output(
            ["git", "log", "-1", f"--format={log_format}"],
            cwd=project_root,
            text=True,
            stderr=subprocess.DEVNULL,
        ).strip()
        sha, author, email, subject, refs = out.split("|", 4)
        # Try to extract current branch
        branch = "unknown"
        try:
            branch = subprocess.check_output(
                ["git", "rev-parse", "--abbrev-ref", "HEAD"],
                cwd=project_root,
                text=True,
                stderr=subprocess.DEVNULL,
            ).strip()
        except subprocess.CalledProcessError:
            pass
        return {
            "sha": sha,
            "author": author,
            "email": email,
            "subject": subject,
            "branch": branch,
        }
    except subprocess.CalledProcessError as e:
        return {
            "sha": "unknown",
            "author": "unknown",
            "email": "unknown",
            "subject": f"error: {e}",
            "branch": "unknown",
        }


def log_commit(project_root: Path | None = None) -> Path | None:
    if project_root is None:
        project_root = get_project_root()

    log_dir = project_root / ".zed-hours"
    log_dir.mkdir(parents=True, exist_ok=True)

    commit_info = get_last_commit_info(project_root)
    record = {
        "type": "commit",
        "timestamp": datetime.now(timezone.utc).astimezone().isoformat(timespec="seconds"),
        "repo": str(project_root),
        **commit_info,
    }

    log_file = log_dir / "commits.jsonl"
    with log_file.open("a", encoding="utf-8") as f:
        f.write(json.dumps(record, ensure_ascii=False) + "\n")

    return log_file


def main() -> None:
    log_file = log_commit()
    if log_file:
        print(f"Logged commit to {log_file}")


if __name__ == "__main__":
    main()