package admin

import (
	"context"
	"fmt"
	"math"
	"strings"
	"time"

	v1 "github.com/go-nunu/nunu-layout-advanced/api/v1"
	admin "github.com/go-nunu/nunu-layout-advanced/api/v1/admin"
	"github.com/go-nunu/nunu-layout-advanced/internal/model"
	"github.com/go-nunu/nunu-layout-advanced/internal/repository"
	"gorm.io/gorm"
)

type LogRepository interface {
	GetLog(ctx context.Context, id int64) (*model.Log, error)
	GetLogList(ctx context.Context, req admin.SearchLogParams) (*v1.PaginatedResponse[model.Log], error)
}

func NewLogRepository(
	repository *repository.Repository,
) LogRepository {
	return &logRepository{
		Repository: repository,
	}
}

type logRepository struct {
	*repository.Repository
}

func (r *logRepository) GetLog(ctx context.Context, id int64) (*model.Log, error) {
	var res model.Log
	
	// 使用依赖注入的分表管理器
	shardingMgr := r.Manager
	
	// 获取存在的分表
	existingTables := shardingMgr.GetTableNamesWithExistenceCheck(r.DBWithName(ctx, "admin"), "log", nil, nil)
	
	// 在各个分表中查找
	for _, tableName := range existingTables {
		err := r.DBWithName(ctx, "admin").Table(tableName).Where("id = ?", id).First(&res).Error
		if err == nil {
			res.SetTableName(tableName)
			return &res, nil
		}
	}
	
	return nil, fmt.Errorf("未找到ID为 %d 的日志记录", id)
}

func (r *logRepository) GetLogList(ctx context.Context, req admin.SearchLogParams) (*v1.PaginatedResponse[model.Log], error) {
	// 使用依赖注入的分表管理器
	shardingMgr := r.Manager
	
	// 解析时间范围(如果有的话)
	var startTime, endTime *time.Time
	// TODO: 这里可以根据req中的时间字段来确定查询范围
	// 暂时查询最近3个月的数据
	
	// 获取需要查询的表
	existingTables := shardingMgr.GetTableNamesWithExistenceCheck(r.DBWithName(ctx, "admin"), "log", startTime, endTime)
	
	if len(existingTables) == 0 {
		// 没有分表，返回空结果
		return &v1.PaginatedResponse[model.Log]{
			Records:    []model.Log{},
			Page:       1,
			PageSize:   10,
			Total:      0,
			TotalPages: 0,
		}, nil
	}
	
	if len(existingTables) == 1 {
		// 只有一个表，直接查询
		return r.queryFromSingleTable(ctx, req, existingTables[0])
	}
	
	// 跨表分页查询
	return r.queryFromMultipleTables(ctx, req, existingTables)
}

// queryFromSingleTable 单表查询
func (r *logRepository) queryFromSingleTable(ctx context.Context, req admin.SearchLogParams, tableName string) (*v1.PaginatedResponse[model.Log], error) {
	var res []model.Log
	var total int64

	query := r.DBWithName(ctx, "admin").Table(tableName)
	query = r.applyFilters(query, req)

	if err := query.Count(&total).Error; err != nil {
		return nil, err
	}

	page := req.Current
	pageSize := req.PageSize

	if page <= 0 {
		page = 1
	}

	if pageSize <= 0 {
		pageSize = 10
	} else if pageSize > 100 {
		pageSize = 100
	}

	offset := (page - 1) * pageSize
	
	if req.Column != "" {
		query = query.Order(req.Column + " " + req.Order)
	}
	
	result := query.Offset(offset).Limit(pageSize).Find(&res)
	if result.Error != nil {
		return nil, result.Error
	}

	return &v1.PaginatedResponse[model.Log]{
		Records:    res,
		Page:       page,
		PageSize:   pageSize,
		Total:      total,
		TotalPages: int(math.Ceil(float64(total) / float64(pageSize))),
	}, nil
}

// queryFromMultipleTables 多表联合查询
func (r *logRepository) queryFromMultipleTables(ctx context.Context, req admin.SearchLogParams, tableNames []string) (*v1.PaginatedResponse[model.Log], error) {
	var allResults []model.Log
	var totalCount int64

	// 先计算总数
	for _, tableName := range tableNames {
		var count int64
		query := r.DBWithName(ctx, "admin").Table(tableName)
		query = r.applyFilters(query, req)
		
		if err := query.Count(&count).Error; err != nil {
			return nil, err
		}
		totalCount += count
	}

	page := req.Current
	pageSize := req.PageSize

	if page <= 0 {
		page = 1
	}

	if pageSize <= 0 {
		pageSize = 10
	} else if pageSize > 100 {
		pageSize = 100
	}

	// 计算需要跳过的记录数
	offset := (page - 1) * pageSize
	limit := pageSize
	currentOffset := 0

	// 逐表查询直到获取足够的记录
	for _, tableName := range tableNames {
		if limit <= 0 {
			break
		}

		var tableCount int64
		countQuery := r.DBWithName(ctx, "admin").Table(tableName)
		countQuery = r.applyFilters(countQuery, req)
		if err := countQuery.Count(&tableCount).Error; err != nil {
			return nil, err
		}

		// 如果当前表的记录数不足以满足offset要求，跳过这个表
		if currentOffset+int(tableCount) <= offset {
			currentOffset += int(tableCount)
			continue
		}

		// 计算在当前表中的offset
		tableOffset := offset - currentOffset
		if tableOffset < 0 {
			tableOffset = 0
		}

		var tableResults []model.Log
		query := r.DBWithName(ctx, "admin").Table(tableName)
		query = r.applyFilters(query, req)
		
		if req.Column != "" {
			query = query.Order(req.Column + " " + req.Order)
		}

		err := query.Offset(tableOffset).Limit(limit).Find(&tableResults).Error
		if err != nil {
			return nil, err
		}

		// 设置表名
		for i := range tableResults {
			tableResults[i].SetTableName(tableName)
		}

		allResults = append(allResults, tableResults...)
		limit -= len(tableResults)
		currentOffset += int(tableCount)
	}

	return &v1.PaginatedResponse[model.Log]{
		Records:    allResults,
		Page:       page,
		PageSize:   pageSize,
		Total:      totalCount,
		TotalPages: int(math.Ceil(float64(totalCount) / float64(pageSize))),
	}, nil
}

// applyFilters 应用查询过滤条件
func (r *logRepository) applyFilters(query *gorm.DB, req admin.SearchLogParams) *gorm.DB {
	if req.RequestIp != "" {
		trimmedName := strings.TrimSpace(req.RequestIp)
		query = query.Where("request_ip LIKE CONCAT('%', ?, '%')", trimmedName)
	}

	if req.Uid != 0 {
		query = query.Where("uid = ?", req.Uid)
	}

	if req.Api != "" {
		trimmedName := strings.TrimSpace(req.Api)
		query = query.Where("api LIKE CONCAT('%', ?, '%')", trimmedName)
	}

	if req.Message != "" {
		trimmedName := strings.TrimSpace(req.Message)
		query = query.Where("message LIKE CONCAT('%', ?, '%')", trimmedName)
	}

	if req.ExtraData != "" {
		trimmedName := strings.TrimSpace(req.ExtraData)
		query = query.Where("extra_data LIKE CONCAT('%', ?, '%')", trimmedName)
	}

	return query
}