package handler

import (
	"fmt"
	"net/http"
	"time"

	"sql-platform/internal/middleware"
	"sql-platform/internal/model"

	"github.com/gin-gonic/gin"
)

// GET /api/v1/tickets/statistics
func TicketStatistics(c *gin.Context) {
	userID, _, role := middleware.GetCurrentUser(c)
	
	type statusCount struct {
		Status string `json:"status"`
		Count  int64  `json:"count"`
	}
	var counts []statusCount
	
	query := model.DB.Model(&model.Ticket{}).Select("status, count(*) as count")
	
	// Filter by user role
	switch role {
	case "developer":
		query = query.Where("applicant_id = ?", userID)
	case "dba", "auditor":
		// DBA sees tickets they submitted + tickets they need to approve
		query = query.Where(
			"applicant_id = ? OR id IN (SELECT ticket_id FROM ticket_approvals WHERE approver_id = ?)",
			userID, userID,
		)
	// admin sees everything
	}
	
	query.Group("status").Scan(&counts)
	
	stats := model.TicketStatistics{}
	for _, c := range counts {
		switch c.Status {
		case "pending":
			stats.Pending = int(c.Count)
		case "reviewing":
			stats.Reviewing = int(c.Count)
		case "executing":
			stats.Executing = int(c.Count)
		case "completed":
			stats.Completed = int(c.Count)
		case "failed":
			stats.Failed = int(c.Count)
		case "rejected":
			stats.Rejected = int(c.Count)
		}
	}
	stats.Total = stats.Pending + stats.Reviewing + stats.Executing + stats.Completed + stats.Failed + stats.Rejected
	
	c.JSON(http.StatusOK, stats)
}

// GET /api/v1/tickets
func ListTickets(c *gin.Context) {
	userID, _, role := middleware.GetCurrentUser(c)
	status := c.Query("status")
	page := 1
	limit := 20
	
	query := model.DB.Model(&model.Ticket{}).Order("id DESC")
	
	// Filter by user role
	switch role {
	case "developer":
		query = query.Where("applicant_id = ?", userID)
	case "dba", "auditor":
		query = query.Where(
			"applicant_id = ? OR id IN (SELECT ticket_id FROM ticket_approvals WHERE approver_id = ?)",
			userID, userID,
		)
	}
	
	if status != "" && status != "all" {
		query = query.Where("status = ?", status)
	}
	
	var total int64
	query.Count(&total)
	
	var tickets []model.Ticket
	query.Offset((page - 1) * limit).Limit(limit).Find(&tickets)
	
	c.JSON(http.StatusOK, gin.H{
		"items": tickets,
		"total": total,
		"page":  page,
		"limit": limit,
	})
}

// GET /api/v1/tickets/:id
func GetTicket(c *gin.Context) {
	id := c.Param("id")
	var ticket model.Ticket
	if err := model.DB.First(&ticket, id).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"detail": "Ticket not found"})
		return
	}
	
	// Get approvals
	var approvals []model.TicketApproval
	model.DB.Where("ticket_id = ?", id).Order("step_number").Find(&approvals)
	
	// Get SQL items
	var sqlItems []model.TicketSQLItem
	model.DB.Where("ticket_id = ?", id).Order("seq").Find(&sqlItems)
	
	c.JSON(http.StatusOK, gin.H{
		"ticket":     ticket,
		"approvals":  approvals,
		"sql_items":  sqlItems,
	})
}

// POST /api/v1/tickets
func CreateTicket(c *gin.Context) {
	userID, _, _ := middleware.GetCurrentUser(c)
	
	var input struct {
		Title          string  `json:"title" binding:"required"`
		DBType         string  `json:"db_type" binding:"required"`
		InstanceID     int     `json:"instance_id" binding:"required"`
		TargetDatabase string  `json:"target_database" binding:"required"`
		SQLContent     string  `json:"sql_content" binding:"required"`
		RollbackSQL    *string `json:"rollback_sql"`
		Priority       *string `json:"priority"`
		Reason         *string `json:"reason"`
		WorkflowID     *int    `json:"workflow_id"`
		RiskLevel      *string `json:"risk_level"`
		ExecStrategy   *string `json:"exec_strategy"`
	}
	
	if err := c.ShouldBindJSON(&input); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"detail": err.Error()})
		return
	}
	
	status := "pending"
	priority := "medium"
	riskLevel := "low"
	execStrategy := "stop_on_error"
	
	if input.Priority != nil {
		priority = *input.Priority
	}
	if input.RiskLevel != nil {
		riskLevel = *input.RiskLevel
	}
	if input.ExecStrategy != nil {
		execStrategy = *input.ExecStrategy
	}
	
	// Generate ticket number
	now := time.Now()
	ticketNo := now.Format("20060102") + "-" + fmt.Sprintf("%04d", time.Now().UnixNano()%10000)
	
	ticket := model.Ticket{
		Title:          input.Title,
		DBType:         input.DBType,
		InstanceID:     input.InstanceID,
		TargetDatabase: input.TargetDatabase,
		SQLContent:     input.SQLContent,
		RollbackSQL:    input.RollbackSQL,
		Status:         &status,
		Priority:       &priority,
		ApplicantID:    userID,
		Reason:         input.Reason,
		WorkflowID:     input.WorkflowID,
		RiskLevel:      &riskLevel,
		ExecStrategy:   &execStrategy,
		TicketNo:       &ticketNo,
	}
	
	if err := model.DB.Create(&ticket).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"detail": err.Error()})
		return
	}
	
	c.JSON(http.StatusCreated, ticket)
}

// POST /api/v1/tickets/:id/approve
func ApproveTicket(c *gin.Context) {
	id := c.Param("id")
	userID, _, _ := middleware.GetCurrentUser(c)
	
	var ticket model.Ticket
	if err := model.DB.First(&ticket, id).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"detail": "Ticket not found"})
		return
	}
	
	var input struct {
		Action  string  `json:"action" binding:"required"` // approve, reject
		Comment *string `json:"comment"`
	}
	if err := c.ShouldBindJSON(&input); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"detail": err.Error()})
		return
	}
	
	now := time.Now()
	
	// Update approval record
	var approval model.TicketApproval
	if err := model.DB.Where("ticket_id = ? AND approver_id = ? AND action IS NULL", id, userID).First(&approval).Error; err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"detail": "No pending approval for you"})
		return
	}
	
	approval.Action = &input.Action
	approval.Comment = input.Comment
	approval.ActualApproverID = &userID
	approval.CompletedAt = &now
	model.DB.Save(&approval)
	
	// Update ticket status
	newStatus := "approved"
	if input.Action == "reject" {
		newStatus = "rejected"
	} else if input.Action == "approve" {
		// Check if there are more pending approvals
		var pendingCount int64
		model.DB.Model(&model.TicketApproval{}).Where("ticket_id = ? AND action IS NULL", id).Count(&pendingCount)
		if pendingCount > 0 {
			newStatus = "reviewing"
		}
	}
	
	ticket.Status = &newStatus
	ticket.ReviewTime = &now
	model.DB.Save(&ticket)
	
	c.JSON(http.StatusOK, gin.H{"ticket": ticket, "approval": approval})
}

// POST /api/v1/tickets/:id/execute
func ExecuteTicket(c *gin.Context) {
	id := c.Param("id")
	
	var ticket model.Ticket
	if err := model.DB.First(&ticket, id).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"detail": "Ticket not found"})
		return
	}
	
	status := "executing"
	ticket.Status = &status
	now := time.Now()
	ticket.ExecuteTime = &now
	model.DB.Save(&ticket)
	
	// TODO: actual SQL execution
	
	c.JSON(http.StatusOK, gin.H{"message": "Execution started", "ticket_id": ticket.ID})
}