#!/usr/bin/env python3
"""Job records for submit.sh and poll-and-land.sh (specs/job-submit-land.md): one JSON file
per job, <dir>/<name>.json, in a directory outside the repository (JOBS_STATE_DIR, default
$HOME/.local/state/nev-jobs), so no host or address can reach a commit.

    records.py <dir> get <name> <field>             prints the field ("" when absent)
    records.py <dir> set <name> <field>=<value>...  creates or updates the record
    records.py <dir> open                           "<name> <run id>" for every record whose
                                                    outcome is empty and that has a run id

A record holds:
    name      the job's name
    resends   how many times submit.sh enqueued it after the first (a number; resends
              after a `run` step exit 3, and resends of a needs-person record, are not
              counted)
    run_id    the last Dagu run id, which `bench/dagu-lane.sh watch` needs
    outcome   empty while the job is in Dagu's hands, then landed, refused, conflict,
              failed, stopped, parked or needs-person (the job's failed rework rounds are
              used up and it waits for a person's call, specs/job-review-rework.md)
    message   the last message
    spec_sha  the spec's blob at base that the last run was sent with (submit.sh); once
              outcome is landed, the blob that landed. submit.sh refuses a landed job only
              while the spec's blob at base is still this one
    base_sha  the full commit the last run was sent with as BASE_SHA (submit.sh). A resend
              whose spec blob is still spec_sha goes at this commit, since the lane resumes
              a job only at the base it started with
Nothing about a run's progress is kept (queued, running or ended comes from Dagu each
time), and neither is the lane (bench/dagu-lane.sh resolves it by index).
"""
import json
import os
import re
import sys
import tempfile

FIELDS = {"name", "resends", "run_id", "outcome", "message", "spec_sha", "base_sha"}
OUTCOMES = {"", "landed", "refused", "conflict", "failed", "stopped", "parked", "needs-person"}
NAME = re.compile(r"^[A-Za-z0-9._-]+$")


def path(d, name):
    if not NAME.match(name) or ".." in name:
        raise SystemExit(f"records: unusable job name: {name}")
    return os.path.join(d, name + ".json")


def load(d, name):
    try:
        with open(path(d, name)) as f:
            return json.load(f)
    except FileNotFoundError:
        return None


def save(d, name, rec):
    os.makedirs(d, mode=0o700, exist_ok=True)
    fd, tmp = tempfile.mkstemp(dir=d, prefix=".rec-")
    with os.fdopen(fd, "w") as f:
        json.dump(rec, f, indent=2, sort_keys=True)
        f.write("\n")
    os.replace(tmp, path(d, name))


def records(d):
    if not os.path.isdir(d):
        return []
    out = []
    for entry in sorted(os.listdir(d)):
        if entry.endswith(".json") and not entry.startswith("."):
            try:
                with open(os.path.join(d, entry)) as f:
                    out.append(json.load(f))
            except (OSError, ValueError):
                continue
    return out


def set_fields(d, name, pairs):
    rec = load(d, name) or {"name": name, "resends": 0, "run_id": "", "outcome": "", "message": "", "spec_sha": ""}
    for pair in pairs:
        field, eq, value = pair.partition("=")
        if not eq or field not in FIELDS or field == "name":
            raise SystemExit(f"records: not a record field: {pair}")
        if field == "resends":
            if not value.isdigit():
                raise SystemExit(f"records: resends is not a count: {value}")
            rec[field] = int(value)
        elif field == "outcome" and value not in OUTCOMES:
            raise SystemExit(f"records: not an outcome: {value}")
        else:
            rec[field] = value
    save(d, name, rec)


def main(argv):
    if len(argv) < 2:
        print(__doc__, file=sys.stderr)
        return 2
    d, cmd, args = argv[0], argv[1], argv[2:]
    if cmd == "get" and len(args) == 2:
        rec = load(d, args[0]) or {}
        value = rec.get(args[1], "")
        print("" if value is None else value)
        return 0
    if cmd == "set" and len(args) >= 2:
        set_fields(d, args[0], args[1:])
        return 0
    if cmd == "open" and not args:
        for r in records(d):
            if not r.get("outcome") and r.get("run_id") and r.get("name"):
                print(r["name"], r["run_id"])
        return 0
    print(__doc__, file=sys.stderr)
    return 2


if __name__ == "__main__":
    sys.exit(main(sys.argv[1:]))