package ddlsync

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

	"dataengine/common/report/config"
	"dataengine/common/report/model"

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

// StatTableCreator 统计宽表创建器
type StatTableCreator struct {
	loader *config.ConfigLoader
}

// NewStatTableCreator 创建统计宽表创建器
func NewStatTableCreator() *StatTableCreator {
	return &StatTableCreator{
		loader: config.GetLoader(),
	}
}

// AutoCreateStatTable 根据配置自动创建统计宽表
func (c *StatTableCreator) AutoCreateStatTable(ctx context.Context, businessCode, reportCode string) (*model.AutoCreateStatTableResp, error) {
	start := time.Now()
	logger := logrus.WithFields(logrus.Fields{
		"businessCode": businessCode,
		"reportCode":   reportCode,
	})

	// 1. 获取报表配置
	report, err := c.loader.GetReport(ctx, businessCode, reportCode)
	if err != nil {
		return nil, fmt.Errorf("获取报表配置失败: %w", err)
	}

	// 2. 获取字段配置
	fields, err := c.loader.GetFields(ctx, businessCode, reportCode)
	if err != nil {
		return nil, fmt.Errorf("获取字段配置失败: %w", err)
	}

	if len(fields) == 0 {
		return nil, fmt.Errorf("报表字段配置为空，请先配置字段")
	}

	// 3. 构建建表SQL
	tableName := report.StatTableName
	sql := c.buildCreateTableSQL(tableName, report, fields)

	logger.Infof("创建统计宽表: %s", tableName)

	// 4. 执行建表
	_, err = gfdb.DB(ctx).Exec(ctx, sql)
	if err != nil {
		return nil, fmt.Errorf("建表失败: %w", err)
	}

	// 5. 创建冲突唯一索引
	if len(report.ConflictKeys) > 0 {
		indexName := fmt.Sprintf("uq_%s_conflict", tableName)
		indexCols := strings.Join(report.ConflictKeys, ", ")
		indexSQL := fmt.Sprintf("CREATE UNIQUE INDEX IF NOT EXISTS %s ON %s (%s)", indexName, tableName, indexCols)
		if _, err := gfdb.DB(ctx).Exec(ctx, indexSQL); err != nil {
			logger.Warnf("创建冲突索引失败: %v", err)
		}
	}

	// 6. 添加字段注释
	for _, f := range fields {
		if f.FieldName != "" {
			commentSQL := fmt.Sprintf("COMMENT ON COLUMN %s.%s IS '%s'", tableName, f.FieldCode, strings.ReplaceAll(f.FieldName, "'", "''"))
			if _, err := gfdb.DB(ctx).Exec(ctx, commentSQL); err != nil {
				logger.Warnf("添加字段注释失败 [%s]: %v", f.FieldCode, err)
			}
		}
	}

	execTime := time.Since(start).Milliseconds()
	logger.Infof("统计宽表 %s 创建完成，字段数: %d，耗时: %dms", tableName, len(fields), execTime)

	return &model.AutoCreateStatTableResp{
		Success:     true,
		TableName:   tableName,
		ColumnCount: len(fields),
		ExecTimeMs:  execTime,
	}, nil
}

// buildCreateTableSQL 构建建表SQL
func (c *StatTableCreator) buildCreateTableSQL(tableName string, report *model.ReportConfig, fields []model.FieldConfig) string {
	var cols []string

	// 基础字段
	cols = append(cols, "id BIGSERIAL PRIMARY KEY")
	cols = append(cols, "tenant_id BIGINT NOT NULL DEFAULT 0")
	cols = append(cols, "business_code VARCHAR(64) NOT NULL DEFAULT ''")
	cols = append(cols, "creator VARCHAR(64) DEFAULT ''")
	cols = append(cols, "created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()")
	cols = append(cols, "updater VARCHAR(64) DEFAULT ''")
	cols = append(cols, "updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()")
	cols = append(cols, "deleted_at TIMESTAMP WITH TIME ZONE")

	// 日期维度字段
	dateField := report.DateField
	if dateField == "" {
		dateField = "stat_date"
	}
	cols = append(cols, fmt.Sprintf("%s VARCHAR(16) NOT NULL DEFAULT ''", dateField))

	// 业务字段
	for _, f := range fields {
		colDef := c.fieldTypeToColumn(f.FieldCode, f.FieldType)
		cols = append(cols, colDef)
	}

	// 原始数据
	cols = append(cols, "raw_data JSONB DEFAULT '{}'")

	sql := fmt.Sprintf("CREATE TABLE IF NOT EXISTS %s (\n  %s\n)", tableName, strings.Join(cols, ",\n  "))

	return sql
}

// fieldTypeToColumn 字段类型转PG列类型
func (c *StatTableCreator) fieldTypeToColumn(fieldCode, fieldType string) string {
	switch fieldType {
	case model.FieldTypeInt, model.FieldTypeFloat:
		return fmt.Sprintf("%s NUMERIC(20,4) DEFAULT 0", fieldCode)
	case model.FieldTypeDate:
		return fmt.Sprintf("%s VARCHAR(16) DEFAULT ''", fieldCode)
	case model.FieldTypeDatetime:
		return fmt.Sprintf("%s TIMESTAMP WITH TIME ZONE", fieldCode)
	case model.FieldTypeJsonb:
		return fmt.Sprintf("%s JSONB DEFAULT '{}'", fieldCode)
	default: // STRING
		return fmt.Sprintf("%s VARCHAR(256) DEFAULT ''", fieldCode)
	}
}

// DropStatTable 删除统计宽表
func (c *StatTableCreator) DropStatTable(ctx context.Context, businessCode, reportCode string) error {
	report, err := c.loader.GetReport(ctx, businessCode, reportCode)
	if err != nil {
		return err
	}

	sql := fmt.Sprintf("DROP TABLE IF EXISTS %s CASCADE", report.StatTableName)
	_, err = gfdb.DB(ctx).Exec(ctx, sql)
	return err
}

// TableExists 检查表是否存在
func (c *StatTableCreator) TableExists(ctx context.Context, tableName string) (bool, error) {
	result, err := gfdb.DB(ctx).GetAll(ctx, "SELECT COUNT(*) FROM pg_tables WHERE tablename = $1", strings.ToLower(tableName))
	if err != nil {
		return false, err
	}
	if len(result) == 0 {
		return false, nil
	}
	count := result[0]["count"].Int()
	return count > 0, nil
}

// GetTableColumns 获取表字段列表
func (c *StatTableCreator) GetTableColumns(ctx context.Context, tableName string) ([]string, error) {
	var columns []string
	sql := `SELECT column_name FROM information_schema.columns WHERE table_name = $1 AND table_schema = 'public' ORDER BY ordinal_position`
	rows, err := gfdb.DB(ctx).GetAll(ctx, sql, strings.ToLower(tableName))
	if err != nil {
		return nil, err
	}
	for _, row := range rows.List() {
		if col, ok := row["column_name"].(string); ok {
			columns = append(columns, col)
		}
	}
	return columns, nil
}

// AlterTableAddColumns 为已存在的表添加新字段
func (c *StatTableCreator) AlterTableAddColumns(ctx context.Context, tableName string, newFields []model.FieldConfig) error {
	existingCols, err := c.GetTableColumns(ctx, tableName)
	if err != nil {
		return err
	}

	existingMap := make(map[string]bool)
	for _, col := range existingCols {
		existingMap[col] = true
	}

	for _, f := range newFields {
		if existingMap[f.FieldCode] {
			continue
		}
		colDef := c.fieldTypeToColumn(f.FieldCode, f.FieldType)
		sql := fmt.Sprintf("ALTER TABLE %s ADD COLUMN IF NOT EXISTS %s", tableName, colDef)
		if _, err := gfdb.DB(ctx).Exec(ctx, sql); err != nil {
			return fmt.Errorf("添加字段 %s 失败: %w", f.FieldCode, err)
		}
	}
	return nil
}