#!/usr/bin/env python3
"""Classify a directory of raw message files into triage lanes.

Usage:
    classify-messages.py INBOX_DIR OUT_JSON OUT_TSV

Rule (deterministic, checked in priority order, case-insensitive against
subject + body):

    ops    -> cron, deploy, disk, backup, server, fail, uptime
    finance-> invoice, payment, expense, salary, bitcoin, fee
    person -> alexander, sol, wizard, troupe, meeting, alex
    other  -> default

Exit code IS the verdict: 0 = every message classified and counts written,
nonzero = anything malformed.
"""

import json
import sys
from pathlib import Path

LANES = [
    ("ops", ["cron", "deploy", "disk", "backup", "server", "fail", "uptime"]),
    ("finance", ["invoice", "payment", "expense", "salary", "bitcoin", "fee"]),
    ("person", ["alexander", "sol", "wizard", "troupe", "meeting", "alex"]),
]
ORDER = ["ops", "finance", "person", "other"]


def classify(subject: str, body: str) -> str:
    text = f"{subject} {body}".lower()
    for lane, kws in LANES:
        if any(kw in text for kw in kws):
            return lane
    return "other"


def read_messages(inbox: Path):
    items = []
    for path in sorted(inbox.glob("*.txt")):
        subject, body = "", ""
        for raw in path.read_text(encoding="utf-8").splitlines():
            if raw.startswith("subject:"):
                subject = raw.split(":", 1)[1].strip()
            elif raw.startswith("body:"):
                body = raw.split(":", 1)[1].strip()
            elif raw == "":
                continue
            else:
                body += " " + raw
        items.append({"file": path.name, "subject": subject, "body": body})
    return items


def main(argv):
    inbox = Path(argv[1])
    out_json = Path(argv[2])
    out_tsv = Path(argv[3])

    items = read_messages(inbox)
    for it in items:
        it["lane"] = classify(it["subject"], it["body"])

    counts = {lane: 0 for lane in ORDER}
    for it in items:
        counts[it["lane"]] += 1

    out_json.write_text(
        json.dumps(
            {
                "tool": "classify-messages.py",
                "inbox": str(inbox),
                "total": len(items),
                "counts": counts,
                "lanes": ORDER,
                "items": [
                    {"file": i["file"], "lane": i["lane"]} for i in items
                ],
            },
            indent=2,
        ),
        encoding="utf-8",
    )

    with out_tsv.open("w", encoding="utf-8") as fh:
        fh.write("file\tlane\n")
        for it in items:
            fh.write(f"{it['file']}\t{it['lane']}\n")

    return 0


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