#!/usr/bin/env python3
"""td — time-track markdown todos identified by ^tid block-refs.

Usage:
    td start <tid> [--file PATH] [--desc TEXT]
    td stop
    td report [FILTER]       # FILTER matches tid or file substring
    td current               # print the currently-running tid (or nothing)
    td tidgen                # print a new unique tid

Log location: $TD_LOG (default ./time.csv)
"""
import argparse, csv, os, re, subprocess, sys
from datetime import datetime
from collections import defaultdict

LOG = os.environ.get("TD_LOG", "./time.csv")
FIELDS = ["started_at", "stopped_at", "tid", "file", "description"]

def now():
    return datetime.now().isoformat(timespec="seconds")

def read_rows():
    if not os.path.exists(LOG):
        return []
    with open(LOG, newline="") as f:
        return list(csv.DictReader(f))

def write_rows(rows):
    with open(LOG, "w", newline="") as f:
        w = csv.DictWriter(f, fieldnames=FIELDS)
        w.writeheader()
        w.writerows(rows)

def lookup_task(tid):
    try:
        out = subprocess.check_output(
            ["rg", "--no-heading", "--with-filename", rf"\^{tid}\b", "."],
            text=True, stderr=subprocess.DEVNULL,
        )
    except (subprocess.CalledProcessError, FileNotFoundError):
        return "", ""
    first = out.splitlines()[0] if out else ""
    if not first:
        return "", ""
    path, _, line = first.partition(":")
    file = path.removeprefix("./")
    desc = re.sub(r"^\s*-\s*\[.\]\s*", "", line)
    desc = re.sub(r"\s*\^\S+\s*$", "", desc).strip()
    return file, desc

def cmd_start(args):
    rows = read_rows()
    ts = now()
    stopped = [r["tid"] for r in rows if not r["stopped_at"]]
    for r in rows:
        if not r["stopped_at"]:
            r["stopped_at"] = ts
    file, desc = args.file or "", args.desc or ""
    if not (file or desc):
        file, desc = lookup_task(args.tid)
        if not file:
            print(f"warning: ^{args.tid} not found in {os.getcwd()} — logging with empty file/desc", file=sys.stderr)
    rows.append({"started_at": ts, "stopped_at": "", "tid": args.tid, "file": file, "description": desc})
    write_rows(rows)
    if stopped:
        print(f"  stopped {', '.join(stopped)} first")
    snippet = f" ({file}: {desc[:50]})" if desc else ""
    print(f"started {args.tid}{snippet}")

def cmd_stop(args):
    rows = read_rows()
    if not rows:
        print(f"no log at {LOG}"); sys.exit(1)
    ts = now()
    stopped = []
    for r in rows:
        if not r["stopped_at"]:
            r["stopped_at"] = ts
            stopped.append(r["tid"])
    if not stopped:
        print("nothing running"); sys.exit(1)
    write_rows(rows)
    print(f"stopped {', '.join(stopped)}")

def cmd_report(args):
    rows = read_rows()
    if not rows:
        print(f"no log at {LOG}"); sys.exit(1)
    totals, files, running = defaultdict(int), {}, []
    for r in rows:
        if args.filter and args.filter not in r["tid"] and args.filter not in r["file"]:
            continue
        start = datetime.fromisoformat(r["started_at"])
        files[r["tid"]] = r["file"]
        if r["stopped_at"]:
            stop = datetime.fromisoformat(r["stopped_at"])
            totals[r["tid"]] += int((stop - start).total_seconds())
        else:
            running.append((r["tid"], start, r["file"], r["description"]))
    for tid in sorted(totals):
        t = totals[tid]
        h, m = t // 3600, (t % 3600) // 60
        print(f"{tid:<24} {h:>3}h{m:02d}m  {files.get(tid,'')}")
    for tid, start, file, desc in running:
        print(f"{tid:<24} RUNNING since {start.strftime('%H:%M')}  {file}: {desc[:40]}")

def cmd_current(args):
    for r in read_rows():
        if not r["stopped_at"]:
            print(r["tid"]); return

def cmd_tidgen(args):
    print(f"tid-{datetime.now().strftime('%Y%m%d-%H%M%S')}")

def main():
    p = argparse.ArgumentParser(prog="td", description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
    sp = p.add_subparsers(dest="cmd", required=True)
    s = sp.add_parser("start"); s.add_argument("tid"); s.add_argument("--file", default=""); s.add_argument("--desc", default=""); s.set_defaults(func=cmd_start)
    sp.add_parser("stop").set_defaults(func=cmd_stop)
    s = sp.add_parser("report"); s.add_argument("filter", nargs="?"); s.set_defaults(func=cmd_report)
    sp.add_parser("current").set_defaults(func=cmd_current)
    sp.add_parser("tidgen").set_defaults(func=cmd_tidgen)
    args = p.parse_args()
    args.func(args)

if __name__ == "__main__":
    main()