package handlers

import (
	"encoding/json"
	"log"
	"net/http"

	"github.com/patel-mann/poll-system/app/internal/models"
)

// ValidatedAddress represents a validated address with coordinates
type ValidatedAddress struct {
	AddressID   int     `json:"address_id"`
	Address     string  `json:"address"`
	Longitude   float64 `json:"longitude"`
	Latitude    float64 `json:"latitude"`
	HouseNumber string  `json:"house_number"`
	StreetName  string  `json:"street_name"`
	StreetType  string  `json:"street_type"`
	Quadrant    string  `json:"street_quadrant"`
	UpdatedAt   string  `json:"updated_at"`
}

// GetValidatedAddressesHandler returns all validated addresses with their coordinates as JSON
func GetValidatedAddressesHandler(w http.ResponseWriter, r *http.Request) {
	// Only allow GET requests
	if r.Method != http.MethodGet {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	// Optional: Check if user is authenticated (depending on your auth system)
	// _, authenticated := models.GetCurrentUserName(r)
	// if !authenticated {
	// 	http.Error(w, "Unauthorized", http.StatusUnauthorized)
	// 	return
	// }

	// Query validated addresses from database
	addresses, err := fetchValidatedAddresses()
	if err != nil {
		log.Printf("Error fetching validated addresses: %v", err)
		http.Error(w, "Internal server error", http.StatusInternalServerError)
		return
	}

	// Set response headers for JSON
	w.Header().Set("Content-Type", "application/json")
	w.Header().Set("Access-Control-Allow-Origin", "*") // Adjust based on your CORS policy

	// Encode and send JSON response
	if err := json.NewEncoder(w).Encode(addresses); err != nil {
		log.Printf("Error encoding JSON response: %v", err)
		http.Error(w, "Error encoding response", http.StatusInternalServerError)
		return
	}


	log.Printf("Successfully returned %d validated addresses", addresses)
}

// fetchValidatedAddresses retrieves all validated addresses from the database
func fetchValidatedAddresses() ([]ValidatedAddress, error) {
	query := `
		SELECT 
			address_id,
			address,
			longitude,
			latitude,
			COALESCE(house_number, '') as house_number,
			COALESCE(street_name, '') as street_name,
			COALESCE(street_type, '') as street_type,
			COALESCE(street_quadrant, '') as street_quadrant,
			updated_at::text
		FROM address_database 
		WHERE visited_validated = true 
		AND longitude IS NOT NULL 
		AND latitude IS NOT NULL
		AND longitude != 0 
		AND latitude != 0
		ORDER BY updated_at DESC
	`

	rows, err := models.DB.Query(query)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var addresses []ValidatedAddress
	for rows.Next() {
		var addr ValidatedAddress
		err := rows.Scan(
			&addr.AddressID,
			&addr.Address,
			&addr.Longitude,
			&addr.Latitude,
			&addr.HouseNumber,
			&addr.StreetName,
			&addr.StreetType,
			&addr.Quadrant,
			&addr.UpdatedAt,
		)
		if err != nil {
			log.Printf("Error scanning address row: %v", err)
			continue
		}
		addresses = append(addresses, addr)
	}

	if err = rows.Err(); err != nil {
		return nil, err
	}

	return addresses, nil
}

// GetValidatedAddressesStatsHandler returns statistics about validated addresses
func GetValidatedAddressesStatsHandler(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	stats, err := getValidatedAddressesStats()
	if err != nil {
		log.Printf("Error fetching address stats: %v", err)
		http.Error(w, "Internal server error", http.StatusInternalServerError)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(stats)
}

// AddressStats represents statistics about addresses
type AddressStats struct {
	TotalValidated      int `json:"total_validated"`
	TotalAddresses      int `json:"total_addresses"`
	ValidatedWithCoords int `json:"validated_with_coords"`
	RecentlyValidated   int `json:"recently_validated_24h"`
}

// getValidatedAddressesStats gets statistics about validated addresses
func getValidatedAddressesStats() (AddressStats, error) {
	var stats AddressStats

	// Get total validated count
	err := models.DB.QueryRow("SELECT COUNT(*) FROM address_database WHERE visited_validated = true").
		Scan(&stats.TotalValidated)
	if err != nil {
		return stats, err
	}

	// Get total addresses count
	err = models.DB.QueryRow("SELECT COUNT(*) FROM address_database").
		Scan(&stats.TotalAddresses)
	if err != nil {
		return stats, err
	}

	// Get validated with coordinates count
	err = models.DB.QueryRow(`
		SELECT COUNT(*) FROM address_database 
		WHERE visited_validated = true 
		AND longitude IS NOT NULL 
		AND latitude IS NOT NULL
		AND longitude != 0 
		AND latitude != 0
	`).Scan(&stats.ValidatedWithCoords)
	if err != nil {
		return stats, err
	}

	// Get recently validated (last 24 hours)
	err = models.DB.QueryRow(`
		SELECT COUNT(*) FROM address_database 
		WHERE visited_validated = true 
		AND updated_at > NOW() - INTERVAL '24 hours'
	`).Scan(&stats.RecentlyValidated)
	if err != nil {
		return stats, err
	}

	return stats, nil
}