package executor

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

	"dataengine/common/report/builder"
	"dataengine/common/report/model"

	"gitea.redpowerfuture.com/red-future/common/db/gfdb"
	"github.com/sirupsen/logrus"
)

// QueryExecutor SQL执行器
type QueryExecutor struct {
	sqlBuilder *builder.SQLBuilder
}

// NewQueryExecutor 创建查询执行器
func NewQueryExecutor() *QueryExecutor {
	return &QueryExecutor{
		sqlBuilder: builder.NewSQLBuilder(),
	}
}

// QueryReportByUserSelect 根据用户选择实时查询报表数据（核心接口）
func (e *QueryExecutor) QueryReportByUserSelect(ctx context.Context, req *model.UserSelectQueryReq) (*model.UserSelectQueryResp, error) {
	start := time.Now()
	logger := logrus.WithFields(logrus.Fields{
		"businessCode": req.BusinessCode,
		"reportCode":   req.ReportCode,
	})

	// 1. 参数校验
	if err := e.validateReq(req); err != nil {
		return nil, fmt.Errorf("参数校验失败: %w", err)
	}

	// 2. 构建查询SQL
	querySQL, queryArgs, metadata, err := e.sqlBuilder.BuildQuerySQL(ctx, req)
	if err != nil {
		return nil, fmt.Errorf("构建查询SQL失败: %w", err)
	}

	logger.Debugf("查询SQL: %s args: %v", querySQL, queryArgs)

	// 3. 获取记录总数
	total, err := e.executeCount(ctx, metadata, queryArgs)
	if err != nil {
		return nil, fmt.Errorf("查询总数失败: %w", err)
	}

	// 4. 分页查询
	if req.Page < 1 {
		req.Page = 1
	}
	if req.PageSize < 1 {
		req.PageSize = 20
	}
	if req.PageSize > 1000 {
		req.PageSize = 1000
	}

	pagedSQL := e.sqlBuilder.AddLimit(querySQL, req.Page, req.PageSize)
	logger.Debugf("分页SQL: %s", pagedSQL)

	dataResult, err := gfdb.DB(ctx).GetAll(ctx, pagedSQL, queryArgs...)
	if err != nil {
		return nil, fmt.Errorf("查询数据失败: %w", err)
	}

	var list []map[string]interface{}
	if dataResult.Len() > 0 {
		list = dataResult.List()
	}

	// 计算总页数
	totalPages := int(math.Ceil(float64(total) / float64(req.PageSize)))

	execTime := time.Since(start).Milliseconds()

	resp := &model.UserSelectQueryResp{
		List:       list,
		Total:      total,
		Page:       req.Page,
		PageSize:   req.PageSize,
		TotalPages: totalPages,
		Sql:        querySQL,
		ExecTimeMs: execTime,
	}

	logger.Infof("报表查询完成, 总数:%d 耗时:%dms", total, execTime)

	return resp, nil
}

// executeCount 执行总数统计
func (e *QueryExecutor) executeCount(ctx context.Context, metadata map[string]interface{}, args []interface{}) (int64, error) {
	countSql, ok := metadata["countSql"].(string)
	if !ok || countSql == "" {
		return 0, nil
	}

	result, err := gfdb.DB(ctx).GetAll(ctx, countSql, args...)
	if err != nil {
		return 0, fmt.Errorf("统计总数失败: %w", err)
	}

	var total int64
	if result.Len() > 0 {
		for k, v := range result.List()[0] {
			_ = k
			if n, ok := v.(int64); ok {
				total = n
			} else {
				total = result[0]["count"].Int64()
			}
			break
		}
	}
	return total, nil
}

// validateReq 校验请求参数
func (e *QueryExecutor) validateReq(req *model.UserSelectQueryReq) error {
	if req.BusinessCode == "" {
		return fmt.Errorf("业务编码不能为空")
	}
	if req.ReportCode == "" {
		return fmt.Errorf("报表编码不能为空")
	}
	if len(req.Indicators) == 0 {
		return fmt.Errorf("必须选择至少一个指标")
	}

	// 校验指标
	for i, ind := range req.Indicators {
		if ind.FieldCode == "" {
			return fmt.Errorf("第%d个指标字段编码不能为空", i+1)
		}
		if ind.Aggregate != "" {
			agg := strings.ToUpper(ind.Aggregate)
			validAggs := map[string]bool{
				"SUM":   true,
				"COUNT": true,
				"AVG":   true,
				"MAX":   true,
				"MIN":   true,
			}
			if !validAggs[agg] {
				return fmt.Errorf("不支持的聚合方式: %s", ind.Aggregate)
			}
		}
	}

	// 校验时间分组
	if req.TimeGroup != "" {
		validGroups := map[string]bool{
			"day":     true,
			"week":    true,
			"month":   true,
			"quarter": true,
		}
		if !validGroups[req.TimeGroup] {
			return fmt.Errorf("不支持的时间分组: %s", req.TimeGroup)
		}
	}

	return nil
}

// RawQuery 执行原始SQL查询（用于特殊场景）
func (e *QueryExecutor) RawQuery(ctx context.Context, sql string, args ...interface{}) ([]map[string]interface{}, error) {
	result, err := gfdb.DB(ctx).GetAll(ctx, sql, args...)
	if err != nil {
		return nil, fmt.Errorf("原始查询失败: %w", err)
	}

	if result.Len() > 0 {
		return result.List(), nil
	}
	return nil, nil
}

// ExecRaw 执行原始SQL（INSERT/UPDATE/DELETE）
func (e *QueryExecutor) ExecRaw(ctx context.Context, sql string, args ...interface{}) error {
	_, err := gfdb.DB(ctx).Exec(ctx, sql, args...)
	return err
}