package cache

import (
	"database/sql"
	"encoding/json"
	"fmt"
	"os"
	"strings"
	"time"

	. "code.hoteas.com/golang/hotime/common"
)

// #region agent log
func debugLog(hypothesisId, location, message string, data map[string]interface{}) {
	logEntry := fmt.Sprintf(`{"hypothesisId":"%s","location":"%s","message":"%s","data":%s,"timestamp":%d,"sessionId":"debug-session"}`,
		hypothesisId, location, message, toJSON(data), time.Now().UnixMilli())
	f, _ := os.OpenFile(`d:\work\hotimev1.5\.cursor\debug.log`, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
	if f != nil {
		f.WriteString(logEntry + "\n")
		f.Close()
	}
}
func toJSON(data map[string]interface{}) string {
	b, _ := json.Marshal(data)
	return string(b)
}

// #endregion

// 表名常量
const (
	CacheTableName        = "hotime_cache"
	CacheHistoryTableName = "hotime_cache_history"
	DefaultCacheTimeout   = 24 * 60 * 60 // 默认过期时间 24 小时
)

type HoTimeDBInterface interface {
	GetPrefix() string
	Query(query string, args ...interface{}) []Map
	Exec(query string, args ...interface{}) (sql.Result, *Error)
	Get(table string, qu ...interface{}) Map
	Select(table string, qu ...interface{}) []Map
	Delete(table string, data map[string]interface{}) int64
	Update(table string, data Map, where Map) int64
	Insert(table string, data map[string]interface{}) int64
	GetType() string
}

type CacheDb struct {
	TimeOut    int64
	DbSet      bool
	SessionSet bool
	HistorySet bool // 是否开启历史记录
	Db         HoTimeDBInterface
	*Error
	ContextBase
	isInit bool
}

func (that *CacheDb) GetError() *Error {
	return that.Error
}

func (that *CacheDb) SetError(err *Error) {
	that.Error = err
}

// getTableName 获取带前缀的表名
func (that *CacheDb) getTableName() string {
	return that.Db.GetPrefix() + CacheTableName
}

// getHistoryTableName 获取带前缀的历史表名
func (that *CacheDb) getHistoryTableName() string {
	return that.Db.GetPrefix() + CacheHistoryTableName
}

// initDbTable 初始化数据库表
func (that *CacheDb) initDbTable() {
	if that.isInit {
		return
	}

	dbType := that.Db.GetType()
	tableName := that.getTableName()
	historyTableName := that.getHistoryTableName()

	// #region agent log
	debugLog("F", "cache_db.go:initDbTable", "initDbTable started", map[string]interface{}{
		"dbType": dbType, "tableName": tableName, "historyTableName": historyTableName, "HistorySet": that.HistorySet,
	})
	// #endregion

	// 检查并创建主表
	if !that.tableExists(tableName) {
		that.createMainTable(dbType, tableName)
	}

	// 检查并迁移旧 cached 表
	oldTableName := that.Db.GetPrefix() + "cached"
	if that.tableExists(oldTableName) {
		that.migrateFromCached(dbType, oldTableName, tableName)
	}

	// 检查并创建历史表（开启历史记录时）
	historyTableExists := that.tableExists(historyTableName)
	// #region agent log
	debugLog("F", "cache_db.go:initDbTable", "history table check", map[string]interface{}{
		"HistorySet": that.HistorySet, "historyTableName": historyTableName, "exists": historyTableExists,
		"shouldCreate": that.HistorySet && !historyTableExists,
	})
	// #endregion
	if that.HistorySet && !historyTableExists {
		that.createHistoryTable(dbType, historyTableName)
		// #region agent log
		debugLog("F", "cache_db.go:initDbTable", "createHistoryTable called", map[string]interface{}{
			"dbType": dbType, "historyTableName": historyTableName,
		})
		// #endregion
	}

	that.isInit = true
}

// tableExists 检查表是否存在
func (that *CacheDb) tableExists(tableName string) bool {
	dbType := that.Db.GetType()

	switch dbType {
	case "mysql":
		dbNames := that.Db.Query("SELECT DATABASE()")
		if len(dbNames) == 0 {
			return false
		}
		dbName := dbNames[0].GetString("DATABASE()")
		res := that.Db.Query("SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA='" + dbName + "' AND TABLE_NAME='" + tableName + "'")
		return len(res) != 0

	case "sqlite":
		res := that.Db.Query(`SELECT name FROM sqlite_master WHERE type='table' AND name='` + tableName + `'`)
		return len(res) != 0

	case "postgres":
		res := that.Db.Query(`SELECT tablename FROM pg_tables WHERE schemaname='public' AND tablename='` + tableName + `'`)
		return len(res) != 0
	}

	return false
}

// createMainTable 创建主表
func (that *CacheDb) createMainTable(dbType, tableName string) {
	var createSQL string

	switch dbType {
	case "mysql":
		createSQL = "CREATE TABLE `" + tableName + "` (" +
			"`id` int(11) unsigned NOT NULL AUTO_INCREMENT," +
			"`key` varchar(64) NOT NULL COMMENT '缓存键'," +
			"`value` text DEFAULT NULL COMMENT '缓存值'," +
			"`end_time` datetime DEFAULT NULL COMMENT '过期时间'," +
			"`state` int(2) DEFAULT '0' COMMENT '状态:0-正常,1-异常,2-隐藏'," +
			"`create_time` datetime DEFAULT NULL COMMENT '创建日期'," +
			"`modify_time` datetime DEFAULT NULL COMMENT '变更时间'," +
			"PRIMARY KEY (`id`)," +
			"UNIQUE KEY `uk_key` (`key`)," +
			"KEY `idx_end_time` (`end_time`)" +
			") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='缓存管理'"

	case "sqlite":
		createSQL = `CREATE TABLE "` + tableName + `" (
			"id" INTEGER PRIMARY KEY AUTOINCREMENT,
			"key" TEXT NOT NULL UNIQUE,
			"value" TEXT,
			"end_time" TEXT,
			"state" INTEGER DEFAULT 0,
			"create_time" TEXT,
			"modify_time" TEXT
		)`

	case "postgres":
		createSQL = `CREATE TABLE "` + tableName + `" (
			"id" SERIAL PRIMARY KEY,
			"key" VARCHAR(64) NOT NULL UNIQUE,
			"value" TEXT,
			"end_time" TIMESTAMP,
			"state" INTEGER DEFAULT 0,
			"create_time" TIMESTAMP,
			"modify_time" TIMESTAMP
		)`
		that.Db.Exec(createSQL)
		// 创建索引
		that.Db.Exec(`CREATE INDEX "idx_` + tableName + `_end_time" ON "` + tableName + `" ("end_time")`)
		return
	}

	that.Db.Exec(createSQL)
}

// createHistoryTable 创建历史表
func (that *CacheDb) createHistoryTable(dbType, tableName string) {
	var createSQL string

	switch dbType {
	case "mysql":
		createSQL = "CREATE TABLE `" + tableName + "` (" +
			"`id` int(11) unsigned NOT NULL AUTO_INCREMENT," +
			"`hotime_cache_id` int(11) unsigned DEFAULT NULL COMMENT '缓存ID'," +
			"`key` varchar(64) DEFAULT NULL COMMENT '缓存键'," +
			"`value` text DEFAULT NULL COMMENT '缓存值'," +
			"`end_time` datetime DEFAULT NULL COMMENT '过期时间'," +
			"`state` int(2) DEFAULT '0' COMMENT '状态:0-正常,1-异常,2-隐藏'," +
			"`create_time` datetime DEFAULT NULL COMMENT '创建日期'," +
			"`modify_time` datetime DEFAULT NULL COMMENT '变更时间'," +
			"PRIMARY KEY (`id`)," +
			"KEY `idx_hotime_cache_id` (`hotime_cache_id`)" +
			") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='缓存历史'"

	case "sqlite":
		createSQL = `CREATE TABLE "` + tableName + `" (
			"id" INTEGER PRIMARY KEY AUTOINCREMENT,
			"hotime_cache_id" INTEGER,
			"key" TEXT,
			"value" TEXT,
			"end_time" TEXT,
			"state" INTEGER DEFAULT 0,
			"create_time" TEXT,
			"modify_time" TEXT
		)`

	case "postgres":
		createSQL = `CREATE TABLE "` + tableName + `" (
			"id" SERIAL PRIMARY KEY,
			"hotime_cache_id" INTEGER,
			"key" VARCHAR(64),
			"value" TEXT,
			"end_time" TIMESTAMP,
			"state" INTEGER DEFAULT 0,
			"create_time" TIMESTAMP,
			"modify_time" TIMESTAMP
		)`
		that.Db.Exec(createSQL)
		// 创建索引
		that.Db.Exec(`CREATE INDEX "idx_` + tableName + `_cache_id" ON "` + tableName + `" ("hotime_cache_id")`)
		return
	}

	that.Db.Exec(createSQL)
}

// migrateFromCached 从旧 cached 表迁移数据
func (that *CacheDb) migrateFromCached(dbType, oldTableName, newTableName string) {
	var migrateSQL string

	switch dbType {
	case "mysql":
		// 去重迁移：取每个 key 的最后一条记录（id 最大）
		migrateSQL = "INSERT INTO `" + newTableName + "` (`key`, `value`, `end_time`, `state`, `create_time`, `modify_time`) " +
			"SELECT c.`key`, c.`value`, FROM_UNIXTIME(c.`endtime`), 0, " +
			"FROM_UNIXTIME(c.`time` / 1000000000), FROM_UNIXTIME(c.`time` / 1000000000) " +
			"FROM `" + oldTableName + "` c " +
			"INNER JOIN (SELECT `key`, MAX(id) as max_id FROM `" + oldTableName + "` GROUP BY `key`) m " +
			"ON c.id = m.max_id"

	case "sqlite":
		migrateSQL = `INSERT INTO "` + newTableName + `" ("key", "value", "end_time", "state", "create_time", "modify_time") ` +
			`SELECT c."key", c."value", datetime(c."endtime", 'unixepoch'), 0, ` +
			`datetime(c."time" / 1000000000, 'unixepoch'), datetime(c."time" / 1000000000, 'unixepoch') ` +
			`FROM "` + oldTableName + `" c ` +
			`INNER JOIN (SELECT "key", MAX(id) as max_id FROM "` + oldTableName + `" GROUP BY "key") m ` +
			`ON c.id = m.max_id`

	case "postgres":
		migrateSQL = `INSERT INTO "` + newTableName + `" ("key", "value", "end_time", "state", "create_time", "modify_time") ` +
			`SELECT c."key", c."value", to_timestamp(c."endtime"), 0, ` +
			`to_timestamp(c."time" / 1000000000), to_timestamp(c."time" / 1000000000) ` +
			`FROM "` + oldTableName + `" c ` +
			`INNER JOIN (SELECT "key", MAX(id) as max_id FROM "` + oldTableName + `" GROUP BY "key") m ` +
			`ON c.id = m.max_id`
	}

	// 执行迁移
	_, err := that.Db.Exec(migrateSQL)
	if err.GetError() == nil {
		// 迁移成功，删除旧表
		var dropSQL string
		switch dbType {
		case "mysql":
			dropSQL = "DROP TABLE `" + oldTableName + "`"
		case "sqlite", "postgres":
			dropSQL = `DROP TABLE "` + oldTableName + `"`
		}
		that.Db.Exec(dropSQL)
	}
}

// writeHistory 写入历史记录
func (that *CacheDb) writeHistory(key string) {
	if !that.HistorySet {
		return
	}

	tableName := that.getTableName()
	historyTableName := that.getHistoryTableName()

	// 查询当前数据
	cached := that.Db.Get(tableName, "*", Map{"key": key})
	if cached == nil {
		return
	}

	// 构建历史记录数据
	historyData := Map{
		"hotime_cache_id": cached.GetInt64("id"),
		"key":             cached.GetString("key"),
		"value":           cached.GetString("value"),
		"end_time":        cached.GetString("end_time"),
		"state":           cached.GetInt("state"),
		"create_time":     cached.GetString("create_time"),
		"modify_time":     cached.GetString("modify_time"),
	}

	// 插入历史表
	that.Db.Insert(historyTableName, historyData)

	// #region agent log
	logFile3, _ := os.OpenFile(`d:\work\hotimev1.5\.cursor\debug.log`, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
	if logFile3 != nil {
		fmt.Fprintf(logFile3, `{"hypothesisId":"C","location":"cache_db.go:writeHistory","message":"history written","data":{"key":"%s","cacheId":%d},"timestamp":%d,"sessionId":"debug-session"}`+"\n", key, cached.GetInt64("id"), time.Now().UnixMilli())
		logFile3.Close()
	}
	// #endregion
}

// get 获取缓存
func (that *CacheDb) get(key string) interface{} {
	tableName := that.getTableName()
	cached := that.Db.Get(tableName, "*", Map{"key": key})

	// #region agent log
	logFile4, _ := os.OpenFile(`d:\work\hotimev1.5\.cursor\debug.log`, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
	if logFile4 != nil {
		found := cached != nil
		fmt.Fprintf(logFile4, `{"hypothesisId":"D","location":"cache_db.go:get","message":"get query","data":{"key":"%s","found":%t},"timestamp":%d,"sessionId":"debug-session"}`+"\n", key, found, time.Now().UnixMilli())
		logFile4.Close()
	}
	// #endregion

	if cached == nil {
		return nil
	}

	// 使用字符串比较判断过期（ISO 格式天然支持）
	endTime := cached.GetString("end_time")
	nowTime := Time2Str(time.Now())
	if endTime != "" && endTime <= nowTime {
		// 惰性删除：过期只返回 nil，不立即删除
		// 依赖随机清理批量删除过期数据
		return nil
	}

	// 直接解析 value，不再需要 {"data": value} 包装
	valueStr := cached.GetString("value")
	if valueStr == "" {
		return nil
	}

	var data interface{}
	err := json.Unmarshal([]byte(valueStr), &data)
	if err != nil {
		return nil
	}

	// #region agent log
	logFile5, _ := os.OpenFile(`d:\work\hotimev1.5\.cursor\debug.log`, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
	if logFile5 != nil {
		fmt.Fprintf(logFile5, `{"hypothesisId":"D","location":"cache_db.go:get","message":"get success","data":{"key":"%s","hasData":true},"timestamp":%d,"sessionId":"debug-session"}`+"\n", key, time.Now().UnixMilli())
		logFile5.Close()
	}
	// #endregion

	return data
}

// set 设置缓存
func (that *CacheDb) set(key string, value interface{}, endTime time.Time) {
	// 直接序列化 value，不再包装
	bte, _ := json.Marshal(value)
	nowTime := Time2Str(time.Now())
	endTimeStr := Time2Str(endTime)

	dbType := that.Db.GetType()
	tableName := that.getTableName()

	// 使用 UPSERT 语法解决并发问题
	switch dbType {
	case "mysql":
		upsertSQL := "INSERT INTO `" + tableName + "` (`key`, `value`, `end_time`, `state`, `create_time`, `modify_time`) " +
			"VALUES (?, ?, ?, 0, ?, ?) " +
			"ON DUPLICATE KEY UPDATE `value`=VALUES(`value`), `end_time`=VALUES(`end_time`), `modify_time`=VALUES(`modify_time`)"
		that.Db.Exec(upsertSQL, key, string(bte), endTimeStr, nowTime, nowTime)

	case "sqlite":
		// SQLite: INSERT OR REPLACE 会删除后插入，所以用 UPSERT 语法
		upsertSQL := `INSERT INTO "` + tableName + `" ("key", "value", "end_time", "state", "create_time", "modify_time") ` +
			`VALUES (?, ?, ?, 0, ?, ?) ` +
			`ON CONFLICT("key") DO UPDATE SET "value"=excluded."value", "end_time"=excluded."end_time", "modify_time"=excluded."modify_time"`
		that.Db.Exec(upsertSQL, key, string(bte), endTimeStr, nowTime, nowTime)

	case "postgres":
		upsertSQL := `INSERT INTO "` + tableName + `" ("key", "value", "end_time", "state", "create_time", "modify_time") ` +
			`VALUES ($1, $2, $3, 0, $4, $5) ` +
			`ON CONFLICT ("key") DO UPDATE SET "value"=EXCLUDED."value", "end_time"=EXCLUDED."end_time", "modify_time"=EXCLUDED."modify_time"`
		that.Db.Exec(upsertSQL, key, string(bte), endTimeStr, nowTime, nowTime)

	default:
		// 兼容其他数据库：使用 Update + Insert
		num := that.Db.Update(tableName, Map{
			"value":       string(bte),
			"end_time":    endTimeStr,
			"modify_time": nowTime,
		}, Map{"key": key})
		if num == 0 {
			that.Db.Insert(tableName, Map{
				"key":         key,
				"value":       string(bte),
				"end_time":    endTimeStr,
				"state":       0,
				"create_time": nowTime,
				"modify_time": nowTime,
			})
		}
	}

	// #region agent log
	logFile2, _ := os.OpenFile(`d:\work\hotimev1.5\.cursor\debug.log`, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
	if logFile2 != nil {
		fmt.Fprintf(logFile2, `{"hypothesisId":"B","location":"cache_db.go:set","message":"set completed","data":{"key":"%s","endTime":"%s","dbType":"%s"},"timestamp":%d,"sessionId":"debug-session"}`+"\n", key, endTimeStr, dbType, time.Now().UnixMilli())
		logFile2.Close()
	}
	// #endregion

	// 写入历史记录
	that.writeHistory(key)

	// 随机执行删除过期数据命令（5% 概率）
	if Rand(1000) > 950 {
		nowTimeStr := Time2Str(time.Now())
		that.Db.Delete(tableName, Map{"end_time[<]": nowTimeStr})
	}
}

// delete 删除缓存
func (that *CacheDb) delete(key string) {
	tableName := that.getTableName()
	del := strings.Index(key, "*")
	// 如果通配删除
	if del != -1 {
		key = Substr(key, 0, del)
		that.Db.Delete(tableName, Map{"key[~]": key + "%"})
	} else {
		that.Db.Delete(tableName, Map{"key": key})
	}
}

// Cache 缓存操作入口
// 用法：
//   - Cache(key) - 获取缓存
//   - Cache(key, value) - 设置缓存（使用默认过期时间）
//   - Cache(key, value, timeout) - 设置缓存（指定过期时间，单位：秒）
//   - Cache(key, nil) - 删除缓存
func (that *CacheDb) Cache(key string, data ...interface{}) *Obj {
	that.initDbTable()

	// #region agent log
	logFile, _ := os.OpenFile(`d:\work\hotimev1.5\.cursor\debug.log`, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
	if logFile != nil {
		op := "get"
		if len(data) == 1 && data[0] == nil {
			op = "delete"
		} else if len(data) >= 1 {
			op = "set"
		}
		fmt.Fprintf(logFile, `{"hypothesisId":"A","location":"cache_db.go:Cache","message":"Cache called","data":{"key":"%s","operation":"%s","dataLen":%d},"timestamp":%d,"sessionId":"debug-session"}`+"\n", key, op, len(data), time.Now().UnixMilli())
		logFile.Close()
	}
	// #endregion

	// 获取缓存
	if len(data) == 0 {
		return &Obj{Data: that.get(key)}
	}

	// 删除缓存
	if len(data) == 1 && data[0] == nil {
		that.delete(key)
		return &Obj{Data: nil}
	}

	// 计算过期时间
	var timeout int64
	if len(data) == 1 {
		// 使用配置的 TimeOut，如果为 0 则使用默认值
		timeout = that.TimeOut
		if timeout == 0 {
			timeout = DefaultCacheTimeout
		}
	} else if len(data) >= 2 {
		// 使用指定的超时时间
		that.SetError(nil)
		tempTimeout := ObjToInt64(data[1], that.Error)
		if that.GetError() == nil && tempTimeout > 0 {
			timeout = tempTimeout
		} else {
			timeout = that.TimeOut
			if timeout == 0 {
				timeout = DefaultCacheTimeout
			}
		}
	}

	endTime := time.Now().Add(time.Duration(timeout) * time.Second)
	that.set(key, data[0], endTime)
	return &Obj{Data: nil}
}