#!/usr/bin/env python3
"""Bucket Claude Code and Codex session activity into days per project.

Usage: scan-activity.py --since YYYY-MM-DD [--until YYYY-MM-DD] [--json]
       scan-activity.py --week last|this

Reads ~/.config/hourlog/projects.json for the path-prefix -> project mapping
(see config.example.json). The mapping is machine-local on purpose: this repo
is public and client names are not.

The unit is an "active slot" — a 5-minute window in which at least one message
was written. Slots are a set per (day, project), so a swarm of 40 subagent
transcripts on one project counts once, and two projects worked in parallel
each keep their own slots. Message counts would make one overnight autonomous
run outweigh a real morning; wall-clock presence does not.

Output is a markdown table: one row per day, one column per project, each cell
holding the time that project was actually active. Nothing is extrapolated and
nothing is fitted to a nominal day — some days start early, some run late, and
a guessed number is worse than a small true one.

Measured time is a floor. Meetings, review and thinking leave no transcript,
so the user adds those back; the script never does.

Overlap is divided, not double-counted: five minutes with two projects open is
five minutes of the day, half to each. So the project columns add up to the
'total' column, which is wall-clock presence.
"""
import argparse
import collections
import datetime as dt
import glob
import json
import os
import sys
from zoneinfo import ZoneInfo

CONFIG = os.path.expanduser("~/.config/hourlog/projects.json")
DEFAULTS = {
    "timezone": "Europe/Lisbon",
    "slot_minutes": 5,
    "day_start_hour": 8,
    "day_end_hour": 20,
    "projects": [],
    "exclude": [],
}


def load_config(path):
    cfg = dict(DEFAULTS)
    if os.path.exists(path):
        with open(path) as fh:
            cfg.update(json.load(fh))
    else:
        print(f"no config at {path} — every path will land in 'unmapped'",
              file=sys.stderr)
    # Longest prefix wins, so a worktree dir can override its parent.
    rules = []
    for p in cfg["projects"]:
        for m in p["match"]:
            rules.append((os.path.expanduser(m).rstrip("/"), p["name"]))
    for m in cfg["exclude"]:
        rules.append((os.path.expanduser(m).rstrip("/"), None))
    cfg["_rules"] = sorted(rules, key=lambda r: -len(r[0]))
    return cfg


def classify(cwd, rules):
    """-> project name, or None if excluded, or 'unmapped:<top-3-dirs>'."""
    if not cwd:
        return "unmapped:?"
    for prefix, name in rules:
        if cwd == prefix or cwd.startswith(prefix + "/"):
            return name
    short = cwd.replace(os.path.expanduser("~"), "~")
    return "unmapped:" + "/".join(short.split("/")[:3])


def claude_files(root, cutoff):
    for f in glob.glob(os.path.join(root, "*", "*.jsonl")):
        try:
            if os.stat(f).st_mtime >= cutoff:
                yield f
        except OSError:
            continue


def codex_files(root, cutoff):
    for f in glob.glob(os.path.join(root, "*", "*", "*", "*.jsonl")):
        try:
            if os.stat(f).st_mtime >= cutoff:
                yield f
        except OSError:
            continue


def read_session(path):
    """-> (cwd, [timestamp strings]). Handles both Claude and Codex layouts."""
    cwd, stamps = None, []
    try:
        fh = open(path, errors="replace")
    except OSError:
        return None, []
    with fh:
        for line in fh:
            try:
                d = json.loads(line)
            except ValueError:
                continue
            if cwd is None:
                cwd = d.get("cwd") or (d.get("payload") or {}).get("cwd")
            ts = d.get("timestamp")
            if ts:
                stamps.append(ts)
    return cwd, stamps


def attribute(slots_of, owners, mins):
    """Divide each slot's minutes evenly among the projects live in it.

    Five minutes with two projects open is five minutes of the user's day, not
    ten, so each project gets half. Largest remainder over whole minutes keeps
    the parts summing to wall clock exactly.
    """
    exact = {p: sum(mins / owners[s] for s in ss) for p, ss in slots_of.items()}
    floors = {p: int(v) for p, v in exact.items()}
    left = round(sum(exact.values())) - sum(floors.values())
    for p in sorted(exact, key=lambda p: -(exact[p] - floors[p]))[:left]:
        floors[p] += 1
    return floors


def fmt_dur(minutes):
    """45 -> '45min', 155 -> '2h35', 180 -> '3h', 0 -> '—'."""
    if not minutes:
        return "—"
    if minutes < 60:
        return f"{minutes}min"
    h, m = divmod(minutes, 60)
    return f"{h}h" if not m else f"{h}h{m:02d}"


def fmt_hour_list(hours):
    """[0,7,20,21,22] -> '00h, 07h, 20-22h'."""
    out, run = [], []
    for h in sorted(set(hours)) + [None]:
        if run and h == run[-1] + 1:
            run.append(h)
            continue
        if run:
            out.append(f"{run[0]:02d}h" if len(run) == 1
                       else f"{run[0]:02d}-{run[-1]:02d}h")
        run = [h] if h is not None else []
    return ", ".join(out)


def md_table(rows, align_right=()):
    """Render rows (first is the header) as a padded markdown table."""
    w = [max(len(r[i]) for r in rows) for i in range(len(rows[0]))]
    def line(cells):
        return "| " + " | ".join(
            c.rjust(w[i]) if i in align_right else c.ljust(w[i])
            for i, c in enumerate(cells)) + " |"
    sep = "|" + "|".join(
        ("-" * (w[i] + 1) + ":") if i in align_right else ("-" * (w[i] + 2))
        for i in range(len(w))) + "|"
    return "\n".join([line(rows[0]), sep] + [line(r) for r in rows[1:]])


def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("--since")
    ap.add_argument("--until")
    ap.add_argument("--week", choices=["last", "this"])
    ap.add_argument("--config", default=CONFIG)
    ap.add_argument("--json", action="store_true")
    a = ap.parse_args()

    cfg = load_config(a.config)
    tz = ZoneInfo(cfg["timezone"])
    today = dt.datetime.now(tz).date()

    if a.week:
        monday = today - dt.timedelta(days=today.weekday())
        if a.week == "last":
            monday -= dt.timedelta(days=7)
        since, until = monday, monday + dt.timedelta(days=6)
    elif a.since:
        since = dt.date.fromisoformat(a.since)
        until = dt.date.fromisoformat(a.until) if a.until else today
    else:
        ap.error("need --since or --week")

    start = dt.datetime.combine(since, dt.time(0), tz)
    end = dt.datetime.combine(until, dt.time(23, 59, 59), tz)
    slot = cfg["slot_minutes"] * 60

    # date -> project -> hour -> set of slot indices
    grid = collections.defaultdict(
        lambda: collections.defaultdict(lambda: collections.defaultdict(set)))

    sources = [
        (os.path.expanduser("~/.claude/projects"), claude_files),
        (os.path.expanduser("~/.codex/sessions"), codex_files),
    ]
    nfiles = 0
    for root, lister in sources:
        if not os.path.isdir(root):
            continue
        for f in lister(root, start.timestamp()):
            cwd, stamps = read_session(f)
            proj = classify(cwd, cfg["_rules"])
            if proj is None:
                continue
            hit = False
            for ts in stamps:
                try:
                    t = dt.datetime.fromisoformat(
                        ts.replace("Z", "+00:00")).astimezone(tz)
                except ValueError:
                    continue
                if not (start <= t <= end):
                    continue
                hit = True
                grid[t.date().isoformat()][proj][t.hour].add(
                    int(t.timestamp()) // slot)
            nfiles += hit
            del stamps

    mins = cfg["slot_minutes"]
    report = []
    d = since
    while d <= until:
        per = grid.get(d.isoformat(), {})
        slots_of = {p: {s for ss in hrs.values() for s in ss}
                    for p, hrs in per.items()
                    if not p.startswith("unmapped:")}
        owners = collections.Counter()
        for ss in slots_of.values():
            owners.update(ss)
        share = attribute(slots_of, owners, mins)
        entry = {
            "date": d.isoformat(),
            "weekday": d.strftime("%a"),
            "active_minutes": len(owners) * mins,
            "projects": [],
        }
        raw = {p: sum(len(s) for s in hrs.values()) * mins
               for p, hrs in per.items()}
        for proj in sorted(per, key=lambda p: -raw[p]):
            hrs = sorted(per[proj])
            entry["projects"].append({
                "project": proj,
                "active_minutes": share.get(proj, raw[proj]),
                "raw_minutes": raw[proj],
                "first_hour": hrs[0],
                "last_hour": hrs[-1],
                "outside_workday": [
                    h for h in hrs
                    if h < cfg["day_start_hour"] or h >= cfg["day_end_hour"]
                ],
            })
        report.append(entry)
        d += dt.timedelta(days=1)

    unmapped = sorted(
        {p for e in report for p in
         (x["project"] for x in e["projects"]) if p.startswith("unmapped:")})

    if a.json:
        json.dump({"since": since.isoformat(), "until": until.isoformat(),
                   "slot_minutes": mins, "sessions": nfiles,
                   "unmapped": unmapped, "report": report}, sys.stdout, indent=1)
        print()
        return 0

    print(f"{since} .. {until} — {nfiles} sessions, {mins}-min slots, "
          f"{cfg['timezone']}")
    print("measured active time, nothing extrapolated; "
          "overlapping minutes split evenly between projects\n")

    cols = [p for p in dict.fromkeys(
        x["project"] for e in report for x in e["projects"])
        if not p.startswith("unmapped:")]
    if not cols:
        print("no mapped project activity in this range")
        return 0

    rows = [["day"] + cols + ["total", "window", "flags"]]
    week = collections.Counter()
    week_total = 0
    for e in report:
        if not e["projects"]:
            continue
        by = {p["project"]: p for p in e["projects"]}
        cells = []
        for c in cols:
            p = by.get(c)
            cells.append(fmt_dur(p["active_minutes"]) if p else "—")
            if p:
                week[c] += p["active_minutes"]
        week_total += e["active_minutes"]
        hrs = [h for p in e["projects"] for h in (p["first_hour"], p["last_hour"])]
        window = f"{min(hrs):02d}-{max(hrs):02d}h" if hrs else ""
        flags = []
        outside = sorted({h for p in e["projects"] for h in p["outside_workday"]})
        if outside:
            flags.append("outside " + fmt_hour_list(outside))
        if any(p["project"].startswith("unmapped:") for p in e["projects"]):
            flags.append("unmapped time excluded")
        rows.append([f"{e['date']} {e['weekday']}"] + cells +
                    [fmt_dur(e["active_minutes"]), window, "; ".join(flags)])

    rows.append(["**total**"] +
                [f"**{fmt_dur(week[c])}**" for c in cols] +
                [f"**{fmt_dur(week_total)}**", "", ""])
    right = set(range(1, len(cols) + 2))
    print(md_table(rows, align_right=right))

    if unmapped:
        print("\nunmapped paths — add them to the config or the exclude list:")
        for u in unmapped:
            print("   ", u)
    return 0


if __name__ == "__main__":
    sys.exit(main())