#!/usr/bin/env python3
"""应用 data/pending_model_changes.json → openclaw.json，并重启 Gateway"""
import json, pathlib, subprocess, datetime, shutil, logging, glob
from file_lock import atomic_json_write, atomic_json_read
from utils import get_openclaw_home

log = logging.getLogger('model_change')
logging.basicConfig(level=logging.INFO, format='%(asctime)s [%(name)s] %(message)s', datefmt='%H:%M:%S')

BASE = pathlib.Path(__file__).parent.parent
DATA = BASE / 'data'
OPENCLAW_HOME = get_openclaw_home()
OPENCLAW_CFG = OPENCLAW_HOME / 'openclaw.json'
PENDING = DATA / 'pending_model_changes.json'
CHANGE_LOG = DATA / 'model_change_log.json'
MAX_BACKUPS = 10


def rj(path, default):
    try:
        return json.loads(path.read_text())
    except Exception:
        return default


def cleanup_backups():
    """只保留最近 MAX_BACKUPS 个备份"""
    pattern = str(OPENCLAW_CFG.parent / 'openclaw.json.bak.model-*')
    baks = sorted(glob.glob(pattern))
    for old in baks[:-MAX_BACKUPS]:
        try:
            pathlib.Path(old).unlink()
        except OSError:
            pass


def main():
    if not PENDING.exists():
        return
    pending = rj(PENDING, [])
    if not pending:
        return

    cfg = rj(OPENCLAW_CFG, {})
    agents_list = cfg.get('agents', {}).get('list', [])
    default_model = cfg.get('agents', {}).get('defaults', {}).get('model', {}).get('primary', '')

    applied, errors = [], []
    for change in pending:
        ag_id = change.get('agentId', '').strip()
        new_model = change.get('model', '').strip()
        if not ag_id or not new_model:
            errors.append({'change': change, 'error': 'missing fields'})
            continue
        found = False
        for ag in agents_list:
            if ag.get('id') == ag_id:
                old = ag.get('model', default_model)
                if new_model == default_model:
                    ag.pop('model', None)
                else:
                    ag['model'] = new_model
                applied.append({'at': datetime.datetime.now().isoformat(), 'agentId': ag_id, 'oldModel': old, 'newModel': new_model})
                found = True
                break
        if not found:
            errors.append({'change': change, 'error': f'agent {ag_id} not found'})

    if applied:
        # 只有内容真正变化时才备份和写入
        new_cfg = dict(cfg)
        new_cfg['agents'] = dict(cfg.get('agents', {}))
        new_cfg['agents']['list'] = agents_list
        old_text = json.dumps(cfg, ensure_ascii=False, sort_keys=True)
        new_text = json.dumps(new_cfg, ensure_ascii=False, sort_keys=True)
        if old_text != new_text:
            bak = OPENCLAW_CFG.parent / f'openclaw.json.bak.model-{datetime.datetime.now().strftime("%Y%m%d-%H%M%S")}'
            shutil.copy2(OPENCLAW_CFG, bak)
            cleanup_backups()
            atomic_json_write(OPENCLAW_CFG, new_cfg)
        cfg = new_cfg

        log_data = rj(CHANGE_LOG, [])
        if not isinstance(log_data, list):
            log_data = []
        log_data.extend(applied)
        if len(log_data) > 200:
            log_data = log_data[-200:]
        atomic_json_write(CHANGE_LOG, log_data)

        for e in applied:
            log.info(f'{e["agentId"]}: {e["oldModel"]} → {e["newModel"]}')

        restart_ok = False
        rollback = False
        try:
            r = subprocess.run(['openclaw', 'gateway', 'restart'], capture_output=True, text=True, timeout=30)
            restart_ok = r.returncode == 0
            log.info(f'gateway restart rc={r.returncode}')
        except Exception as e:
            log.error(f'gateway restart failed: {e}')
            # 回滚配置
            if bak.exists():
                shutil.copy2(bak, OPENCLAW_CFG)
                log.warning('rolled back openclaw.json from backup')
                rollback = True
                for a in applied:
                    a['rolledBack'] = True

        atomic_json_write(PENDING, [])
        atomic_json_write(DATA / 'last_model_change_result.json', {
            'at': datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S'),
            'applied': applied, 'errors': errors,
            'gatewayRestarted': restart_ok, 'rolledBack': rollback,
        })
    elif errors:
        log.warning(f'{len(errors)} changes failed, 0 applied')
        atomic_json_write(PENDING, [])


if __name__ == '__main__':
    main()