#!/usr/bin/env python3
"""
Idempotent DDL migration for Postgres incident log backend.

Creates tables: incidents, incident_events, incident_artifacts (+ indexes).

Usage:
    DATABASE_URL=postgresql://... python3 ops/scripts/migrate_incidents_postgres.py
    python3 ops/scripts/migrate_incidents_postgres.py --dry-run

Exit codes: 0 = success, 1 = error
"""
from __future__ import annotations

import argparse
import os
import sys
import textwrap

DDL = textwrap.dedent("""\
    -- ─── incidents ──────────────────────────────────────────────────────────
    CREATE TABLE IF NOT EXISTS incidents (
        id            TEXT         PRIMARY KEY,
        workspace_id  TEXT         NOT NULL DEFAULT 'default',
        service       TEXT         NOT NULL,
        env           TEXT         NOT NULL DEFAULT 'prod',
        severity      TEXT         NOT NULL DEFAULT 'P2',
        status        TEXT         NOT NULL DEFAULT 'open',
        title         TEXT         NOT NULL,
        summary       TEXT,
        started_at    TIMESTAMPTZ  NOT NULL,
        ended_at      TIMESTAMPTZ,
        created_by    TEXT         NOT NULL,
        created_at    TIMESTAMPTZ  NOT NULL DEFAULT NOW(),
        updated_at    TIMESTAMPTZ  NOT NULL DEFAULT NOW()
    );

    CREATE INDEX IF NOT EXISTS idx_incidents_ws_created
        ON incidents (workspace_id, created_at);
    CREATE INDEX IF NOT EXISTS idx_incidents_service_status
        ON incidents (service, status);

    -- ─── incident_events (timeline) ─────────────────────────────────────────
    CREATE TABLE IF NOT EXISTS incident_events (
        id            BIGSERIAL    PRIMARY KEY,
        incident_id   TEXT         NOT NULL REFERENCES incidents(id) ON DELETE CASCADE,
        ts            TIMESTAMPTZ  NOT NULL DEFAULT NOW(),
        type          TEXT         NOT NULL,
        message       TEXT         NOT NULL DEFAULT '',
        meta          JSONB
    );

    CREATE INDEX IF NOT EXISTS idx_incident_events_inc_ts
        ON incident_events (incident_id, ts);

    -- ─── incident_artifacts ──────────────────────────────────────────────────
    CREATE TABLE IF NOT EXISTS incident_artifacts (
        id            BIGSERIAL    PRIMARY KEY,
        incident_id   TEXT         NOT NULL REFERENCES incidents(id) ON DELETE CASCADE,
        ts            TIMESTAMPTZ  NOT NULL DEFAULT NOW(),
        kind          TEXT         NOT NULL,
        format        TEXT         NOT NULL DEFAULT 'json',
        path          TEXT         NOT NULL,
        sha256        TEXT         NOT NULL DEFAULT '',
        size_bytes    INT          NOT NULL DEFAULT 0
    );

    CREATE INDEX IF NOT EXISTS idx_incident_artifacts_inc_ts
        ON incident_artifacts (incident_id, ts);
""")


def run(dsn: str, dry_run: bool) -> int:
    try:
        import psycopg2  # type: ignore
    except ImportError:
        try:
            import subprocess
            subprocess.check_call([sys.executable, "-m", "pip", "install", "--quiet", "psycopg2-binary"])
            import psycopg2  # type: ignore  # noqa: F811
        except Exception as pip_err:
            print(f"[ERROR] psycopg2 not available: {pip_err}", file=sys.stderr)
            return 1

    print(f"[migrate-incidents] Connecting to: {dsn[:40]}…")
    if dry_run:
        print("[migrate-incidents] DRY-RUN — DDL only:\n")
        print(DDL)
        return 0

    try:
        conn = psycopg2.connect(dsn)
        conn.autocommit = False
        cur = conn.cursor()
        cur.execute(DDL)
        conn.commit()
        cur.close()
        conn.close()
        print("[migrate-incidents] ✅ Incident tables created/verified successfully.")
        return 0
    except Exception as exc:
        print(f"[migrate-incidents] ❌ Migration failed: {exc}", file=sys.stderr)
        return 1


def main() -> None:
    parser = argparse.ArgumentParser(description="Idempotent Postgres incident DDL migration")
    parser.add_argument("--dry-run", action="store_true")
    parser.add_argument(
        "--dsn",
        default=os.getenv("DATABASE_URL") or os.getenv("POSTGRES_DSN", ""),
    )
    args = parser.parse_args()
    if not args.dsn:
        print("[migrate-incidents] ERROR: DATABASE_URL not set.", file=sys.stderr)
        sys.exit(1)
    sys.exit(run(args.dsn, args.dry_run))


if __name__ == "__main__":
    main()