#!/usr/bin/env python3
"""
Migration 续：
1. 给 requirement_node / requirement_pattern 加 `version` 列，并把 version 并入 PK
   - 老数据（requirement_node 210 行）默认 version='v0'
2. 从 frontend/public/requirements_planb.json 回填 requirement_pattern
   - version='ruotian'
   - execution_id=56

按 db-operations.md：
- autocommit=True
- SET statement_timeout='30s'
- ADD COLUMN NOT NULL DEFAULT 拆两步：先 DEFAULT（补齐数据），再 SET NOT NULL
- DROP CONSTRAINT + ADD PRIMARY KEY 替换主键（不使用 RENAME / DROP COLUMN）
"""
import json
import sys
import time
from pathlib import Path

sys.path.insert(0, str(Path(__file__).parent.parent.parent))
from knowhub.knowhub_db.pg_capability_store import PostgreSQLCapabilityStore

EXECUTION_ID = 56
PATTERN_VERSION = 'ruotian'
PLANB_PATH = Path('/Users/sunlit/Code/Agent/knowhub/frontend/public/requirements_planb.json')


def log(msg):
    print(f'[{time.strftime("%H:%M:%S")}] {msg}', flush=True)


def kill_idle_in_tx(cur):
    cur.execute("""
        SELECT pid FROM pg_stat_activity
         WHERE state='idle in transaction'
           AND pid != pg_backend_pid()
           AND datname = current_database()
    """)
    pids = [r['pid'] for r in cur.fetchall()]
    for pid in pids:
        cur.execute('SELECT pg_terminate_backend(%s)', (pid,))
    log(f'  killed idle-in-tx sessions: {pids or "none"}')


def add_version_and_rebuild_pk(cur, table, pk_cols):
    log(f'[{table}] ADD COLUMN version VARCHAR(32) DEFAULT v0')
    cur.execute(f"ALTER TABLE {table} ADD COLUMN IF NOT EXISTS version VARCHAR(32) DEFAULT 'v0'")
    log(f'  ✓ done')

    # 补齐空值（幂等）
    cur.execute(f"UPDATE {table} SET version = 'v0' WHERE version IS NULL")
    log(f'  filled-in NULL -> v0: {cur.rowcount or 0} rows')

    log(f'[{table}] ALTER COLUMN version SET NOT NULL')
    cur.execute(f"ALTER TABLE {table} ALTER COLUMN version SET NOT NULL")
    log(f'  ✓ done')

    log(f'[{table}] DROP existing PK constraint')
    cur.execute(f"ALTER TABLE {table} DROP CONSTRAINT IF EXISTS {table}_pkey")
    log(f'  ✓ done')

    cols = ', '.join(pk_cols)
    log(f'[{table}] ADD PRIMARY KEY ({cols})')
    cur.execute(f"ALTER TABLE {table} ADD PRIMARY KEY ({cols})")
    log(f'  ✓ done')


def backfill_requirement_pattern(cur):
    data = json.loads(PLANB_PATH.read_text(encoding='utf-8'))
    reqs = data['requirements']
    log(f'Loaded planb: {len(reqs)} requirements (source: {data["source"]})')

    # 筛已在 DB 的 requirement_id
    cur.execute('SELECT id FROM requirement')
    valid_ids = {r['id'] for r in cur.fetchall()}

    inserted = 0
    missing_reqs = []
    total_pairs = 0
    reqs_with_rows = 0

    for r in reqs:
        rid = r.get('requirement_id')
        if rid not in valid_ids:
            missing_reqs.append(rid)
            continue
        patterns = r.get('patterns') or []
        pattern_ids = {p.get('pattern_id') for p in patterns if p.get('pattern_id') is not None}
        if pattern_ids:
            reqs_with_rows += 1
        total_pairs += len(pattern_ids)
        for pid in pattern_ids:
            cur.execute("""
                INSERT INTO requirement_pattern (requirement_id, itemset_id, execution_id, version)
                VALUES (%s, %s, %s, %s)
                ON CONFLICT DO NOTHING
            """, (rid, pid, EXECUTION_ID, PATTERN_VERSION))
            inserted += cur.rowcount or 0

    log(f'Pattern backfill complete:')
    log(f'  reqs in planb:                 {len(reqs)}')
    log(f'  reqs present in DB:            {len(reqs) - len(missing_reqs)}')
    log(f'  reqs with ≥1 pattern row:      {reqs_with_rows}')
    log(f'  total (req,pattern) distinct:  {total_pairs}')
    log(f'  rows inserted (after conflict):{inserted}')
    if missing_reqs:
        log(f'  ⚠️  reqs in planb not in DB ({len(missing_reqs)}): {missing_reqs[:10]}')


def verify(cur):
    for t in ('requirement_node', 'requirement_pattern'):
        cur.execute(f'SELECT COUNT(*) c FROM {t}')
        total = cur.fetchone()['c']
        cur.execute(f'SELECT version, COUNT(*) c FROM {t} GROUP BY version ORDER BY version')
        by_ver = [(r['version'], r['c']) for r in cur.fetchall()]
        log(f'{t}: total={total}, by version: {by_ver}')


def main():
    s = PostgreSQLCapabilityStore()
    cur = s._get_cursor()
    try:
        cur.execute("SET statement_timeout = '30s'")
        kill_idle_in_tx(cur)

        add_version_and_rebuild_pk(
            cur, 'requirement_node',
            ['requirement_id', 'node_id', 'execution_id', 'version'],
        )
        add_version_and_rebuild_pk(
            cur, 'requirement_pattern',
            ['requirement_id', 'itemset_id', 'execution_id', 'version'],
        )

        backfill_requirement_pattern(cur)
        verify(cur)
    finally:
        cur.close()
        s.close()


if __name__ == '__main__':
    main()