"""
数据迁移脚本：从旧 alerts 表迁移到新三表结构

将 alerts 表数据迁移到:
- alarm_event (主表)
- alarm_event_ext (扩展表)
- alarm_llm_analysis (大模型分析表)

运行方式: python -m app.migrations.migrate_to_alarm_event
"""
import json
import sys
import os

# 确保项目根目录在 sys.path
sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__)))))

from datetime import datetime, timezone
from app.models import (
    Alert, AlertStatus, AlertLevel,
    AlarmEvent, AlarmEventExt, AlarmLlmAnalysis,
    init_db, get_session
)
from app.utils.logger import logger


# 旧 level enum → 新 alarm_level 整数
LEVEL_MAP = {
    "low": 1,
    "medium": 2,
    "high": 3,
    "critical": 4,
}

# 旧 status enum → 新 alarm_status
STATUS_MAP = {
    "pending": "NEW",
    "confirmed": "CONFIRMED",
    "ignored": "FALSE",
    "resolved": "CLOSED",
    "dispatched": "CLOSED",
}

# 旧 status → 新 handle_status
HANDLE_STATUS_MAP = {
    "pending": "UNHANDLED",
    "confirmed": "DONE",
    "ignored": "DONE",
    "resolved": "DONE",
    "dispatched": "DONE",
}


def migrate():
    """执行迁移"""
    init_db()

    db = get_session()
    try:
        # 检查是否已有数据
        existing = db.query(AlarmEvent).count()
        if existing > 0:
            print(f"alarm_event 表已有 {existing} 条数据，跳过迁移。")
            print("如需重新迁移，请先清空 alarm_event / alarm_event_ext / alarm_llm_analysis 表。")
            return

        total = db.query(Alert).count()
        if total == 0:
            print("旧 alerts 表为空，无需迁移。")
            return

        print(f"开始迁移 {total} 条告警记录...")

        migrated = 0
        ext_count = 0
        llm_count = 0
        errors = 0

        # 分批处理
        batch_size = 100
        offset = 0

        while offset < total:
            alerts = (
                db.query(Alert)
                .order_by(Alert.id)
                .offset(offset)
                .limit(batch_size)
                .all()
            )

            for alert in alerts:
                try:
                    _migrate_one(db, alert)
                    migrated += 1

                    # 统计扩展记录
                    if any([alert.bind_id, alert.bbox, alert.message]):
                        ext_count += 1
                    if alert.ai_analysis:
                        llm_count += 1

                except Exception as e:
                    errors += 1
                    logger.error(f"迁移告警 {alert.alert_no} 失败: {e}")

            db.commit()
            offset += batch_size
            print(f"  已迁移 {min(offset, total)}/{total}...")

        print(f"\n迁移完成:")
        print(f"  alarm_event:        {migrated} 条")
        print(f"  alarm_event_ext:    {ext_count} 条")
        print(f"  alarm_llm_analysis: {llm_count} 条")
        print(f"  失败:               {errors} 条")

    finally:
        db.close()


def _migrate_one(db, alert: Alert):
    """迁移单条告警"""
    # 1. alarm_event
    old_status = alert.status.value if alert.status else "pending"
    old_level = alert.level.value if alert.level else "medium"

    # confidence: 旧表是 0-100 整数，新表是 0-1 float
    confidence_score = None
    if alert.confidence is not None:
        confidence_score = float(alert.confidence) / 100.0

    # duration_minutes → duration_ms
    duration_ms = None
    if alert.duration_minutes is not None:
        duration_ms = int(alert.duration_minutes) * 60 * 1000

    alarm = AlarmEvent(
        alarm_id=alert.alert_no,
        alarm_type=alert.alert_type,
        algorithm_code=alert.algorithm,
        device_id=alert.camera_id,
        scene_id=alert.roi_id,
        event_time=alert.trigger_time,
        duration_ms=duration_ms,
        alarm_level=LEVEL_MAP.get(old_level, 2),
        confidence_score=confidence_score,
        alarm_status=STATUS_MAP.get(old_status, "NEW"),
        handle_status=HANDLE_STATUS_MAP.get(old_status, "UNHANDLED"),
        snapshot_url=alert.snapshot_url,
        edge_node_id=alert.device_id,
        handler=alert.handled_by,
        handle_remark=alert.handle_remark,
        handled_at=alert.handled_at,
        created_at=alert.created_at,
        updated_at=alert.updated_at,
    )
    db.add(alarm)

    # 2. alarm_event_ext
    ext_data = {}
    if alert.bind_id:
        ext_data["bind_id"] = alert.bind_id
    if alert.bbox:
        ext_data["bbox"] = alert.bbox
    if alert.message:
        ext_data["message"] = alert.message

    if ext_data:
        ext = AlarmEventExt(
            alarm_id=alert.alert_no,
            ext_type="EDGE",
            ext_data=ext_data,
            created_at=alert.created_at,
        )
        db.add(ext)

    # 3. alarm_llm_analysis
    if alert.ai_analysis:
        ai = alert.ai_analysis
        if isinstance(ai, str):
            try:
                ai = json.loads(ai)
            except (json.JSONDecodeError, TypeError):
                ai = {"summary": ai}

        if isinstance(ai, dict):
            analysis = AlarmLlmAnalysis(
                alarm_id=alert.alert_no,
                llm_model=ai.get("model", "unknown"),
                analysis_type="REVIEW",
                summary=ai.get("summary") or ai.get("analysis"),
                is_false_alarm=ai.get("is_false_alarm"),
                risk_score=ai.get("risk_score"),
                confidence_score=ai.get("confidence"),
                suggestion=ai.get("suggestion") or ai.get("recommendation"),
                created_at=alert.updated_at or alert.created_at,
            )
            db.add(analysis)


if __name__ == "__main__":
    migrate()