package handlers

import (
	"fmt"
	"html/template"
	"net/http"
	"path/filepath"
	"strconv"
	"time"

	"github.com/gin-gonic/gin"
	"git.mchus.pro/mchus/quoteforge/internal/localdb"
	"gorm.io/driver/mysql"
	"gorm.io/gorm"
	"gorm.io/gorm/logger"
)

type SetupHandler struct {
	localDB   *localdb.LocalDB
	templates map[string]*template.Template
}

func NewSetupHandler(localDB *localdb.LocalDB, templatesPath string) (*SetupHandler, error) {
	funcMap := template.FuncMap{
		"sub": func(a, b int) int { return a - b },
		"add": func(a, b int) int { return a + b },
	}

	templates := make(map[string]*template.Template)

	// Load setup template (standalone, no base needed)
	setupPath := filepath.Join(templatesPath, "setup.html")
	tmpl, err := template.New("").Funcs(funcMap).ParseFiles(setupPath)
	if err != nil {
		return nil, fmt.Errorf("parsing setup template: %w", err)
	}
	templates["setup.html"] = tmpl

	return &SetupHandler{
		localDB:   localDB,
		templates: templates,
	}, nil
}

// ShowSetup renders the database setup form
func (h *SetupHandler) ShowSetup(c *gin.Context) {
	c.Header("Content-Type", "text/html; charset=utf-8")

	// Get existing settings if any
	settings, _ := h.localDB.GetSettings()

	data := gin.H{
		"Settings": settings,
	}

	tmpl := h.templates["setup.html"]
	if err := tmpl.ExecuteTemplate(c.Writer, "setup.html", data); err != nil {
		c.String(http.StatusInternalServerError, "Template error: %v", err)
	}
}

// TestConnection tests the database connection without saving
func (h *SetupHandler) TestConnection(c *gin.Context) {
	host := c.PostForm("host")
	portStr := c.PostForm("port")
	database := c.PostForm("database")
	user := c.PostForm("user")
	password := c.PostForm("password")

	port := 3306
	if p, err := strconv.Atoi(portStr); err == nil {
		port = p
	}

	dsn := fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?charset=utf8mb4&parseTime=True&loc=Local&timeout=5s",
		user, password, host, port, database)

	db, err := gorm.Open(mysql.Open(dsn), &gorm.Config{
		Logger: logger.Default.LogMode(logger.Silent),
	})
	if err != nil {
		c.JSON(http.StatusOK, gin.H{
			"success": false,
			"error":   fmt.Sprintf("Connection failed: %v", err),
		})
		return
	}

	sqlDB, err := db.DB()
	if err != nil {
		c.JSON(http.StatusOK, gin.H{
			"success": false,
			"error":   fmt.Sprintf("Failed to get database handle: %v", err),
		})
		return
	}
	defer sqlDB.Close()

	if err := sqlDB.Ping(); err != nil {
		c.JSON(http.StatusOK, gin.H{
			"success": false,
			"error":   fmt.Sprintf("Ping failed: %v", err),
		})
		return
	}

	// Check for required tables
	var lotCount int64
	if err := db.Table("lot").Count(&lotCount).Error; err != nil {
		c.JSON(http.StatusOK, gin.H{
			"success": false,
			"error":   fmt.Sprintf("Table 'lot' not found or inaccessible: %v", err),
		})
		return
	}

	// Check write permission
	canWrite := testWritePermission(db)

	c.JSON(http.StatusOK, gin.H{
		"success":   true,
		"lot_count": lotCount,
		"can_write": canWrite,
		"message":   fmt.Sprintf("Connected successfully! Found %d components.", lotCount),
	})
}

// SaveConnection saves the connection settings and signals restart
func (h *SetupHandler) SaveConnection(c *gin.Context) {
	host := c.PostForm("host")
	portStr := c.PostForm("port")
	database := c.PostForm("database")
	user := c.PostForm("user")
	password := c.PostForm("password")

	port := 3306
	if p, err := strconv.Atoi(portStr); err == nil {
		port = p
	}

	// Test connection first
	dsn := fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?charset=utf8mb4&parseTime=True&loc=Local&timeout=5s",
		user, password, host, port, database)

	db, err := gorm.Open(mysql.Open(dsn), &gorm.Config{
		Logger: logger.Default.LogMode(logger.Silent),
	})
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{
			"success": false,
			"error":   fmt.Sprintf("Connection failed: %v", err),
		})
		return
	}

	sqlDB, _ := db.DB()
	sqlDB.Close()

	// Save settings
	if err := h.localDB.SaveSettings(host, port, database, user, password); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{
			"success": false,
			"error":   fmt.Sprintf("Failed to save settings: %v", err),
		})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"success": true,
		"message": "Settings saved. Please restart the application.",
	})
}

// GetStatus returns the current setup status
func (h *SetupHandler) GetStatus(c *gin.Context) {
	hasSettings := h.localDB.HasSettings()
	c.JSON(http.StatusOK, gin.H{
		"configured": hasSettings,
	})
}

func testWritePermission(db *gorm.DB) bool {
	// Simple check: try to create a temporary table and drop it
	testTable := fmt.Sprintf("qt_write_test_%d", time.Now().UnixNano())

	// Try to create a test table
	err := db.Exec(fmt.Sprintf("CREATE TABLE %s (id INT)", testTable)).Error
	if err != nil {
		return false
	}

	// Drop it immediately
	db.Exec(fmt.Sprintf("DROP TABLE %s", testTable))

	return true
}