package models

import (
	"database/sql"
	"fmt"

	"simple_portal/database"
)

// Card represents a navigation card on the portal home page.
type Card struct {
	ID        int    `json:"id"`
	Icon      string `json:"icon"`
	Title     string `json:"title"`
	Subtitle  string `json:"subtitle"`
	URL       string `json:"url"`
	Sort      int    `json:"sort"`
	Enabled   bool   `json:"enabled"`
	CreatedAt string `json:"created_at"`
}

// GetAllCards returns all cards ordered by sort ascending.
func GetAllCards() ([]Card, error) {
	rows, err := database.DB.Query("SELECT id, icon, title, subtitle, url, sort, enabled, created_at FROM cards ORDER BY sort ASC")
	if err != nil {
		return nil, fmt.Errorf("failed to query cards: %w", err)
	}
	defer rows.Close()

	var cards []Card
	for rows.Next() {
		var c Card
		var enabled int
		if err := rows.Scan(&c.ID, &c.Icon, &c.Title, &c.Subtitle, &c.URL, &c.Sort, &enabled, &c.CreatedAt); err != nil {
			return nil, fmt.Errorf("failed to scan card: %w", err)
		}
		c.Enabled = enabled == 1
		cards = append(cards, c)
	}
	return cards, rows.Err()
}

// GetEnabledCards returns only enabled cards ordered by sort ascending.
func GetEnabledCards() ([]Card, error) {
	rows, err := database.DB.Query("SELECT id, icon, title, subtitle, url, sort, enabled, created_at FROM cards WHERE enabled = 1 ORDER BY sort ASC")
	if err != nil {
		return nil, fmt.Errorf("failed to query enabled cards: %w", err)
	}
	defer rows.Close()

	var cards []Card
	for rows.Next() {
		var c Card
		var enabled int
		if err := rows.Scan(&c.ID, &c.Icon, &c.Title, &c.Subtitle, &c.URL, &c.Sort, &enabled, &c.CreatedAt); err != nil {
			return nil, fmt.Errorf("failed to scan card: %w", err)
		}
		c.Enabled = enabled == 1
		cards = append(cards, c)
	}
	return cards, rows.Err()
}

// GetCardByID returns a single card by its ID.
func GetCardByID(id int) (*Card, error) {
	var c Card
	var enabled int
	err := database.DB.QueryRow(
		"SELECT id, icon, title, subtitle, url, sort, enabled, created_at FROM cards WHERE id = ?",
		id,
	).Scan(&c.ID, &c.Icon, &c.Title, &c.Subtitle, &c.URL, &c.Sort, &enabled, &c.CreatedAt)
	if err == sql.ErrNoRows {
		return nil, nil
	}
	if err != nil {
		return nil, fmt.Errorf("failed to query card by id: %w", err)
	}
	c.Enabled = enabled == 1
	return &c, nil
}

// CreateCard inserts a new card with sort = MAX(sort) + 1.
func CreateCard(card *Card) error {
	var maxSort sql.NullInt64
	err := database.DB.QueryRow("SELECT MAX(sort) FROM cards").Scan(&maxSort)
	if err != nil {
		return fmt.Errorf("failed to get max sort: %w", err)
	}

	newSort := 0
	if maxSort.Valid {
		newSort = int(maxSort.Int64) + 1
	}

	enabledInt := 0
	if card.Enabled {
		enabledInt = 1
	}

	result, err := database.DB.Exec(
		"INSERT INTO cards (icon, title, subtitle, url, sort, enabled) VALUES (?, ?, ?, ?, ?, ?)",
		card.Icon, card.Title, card.Subtitle, card.URL, newSort, enabledInt,
	)
	if err != nil {
		return fmt.Errorf("failed to insert card: %w", err)
	}

	lastID, err := result.LastInsertId()
	if err != nil {
		return fmt.Errorf("failed to get last insert id: %w", err)
	}
	card.ID = int(lastID)
	card.Sort = newSort
	return nil
}

// UpdateCard updates an existing card by ID.
func UpdateCard(card *Card) error {
	enabledInt := 0
	if card.Enabled {
		enabledInt = 1
	}

	_, err := database.DB.Exec(
		"UPDATE cards SET icon = ?, title = ?, subtitle = ?, url = ?, sort = ?, enabled = ? WHERE id = ?",
		card.Icon, card.Title, card.Subtitle, card.URL, card.Sort, enabledInt, card.ID,
	)
	if err != nil {
		return fmt.Errorf("failed to update card: %w", err)
	}
	return nil
}

// DeleteCard deletes a card by ID.
func DeleteCard(id int) error {
	_, err := database.DB.Exec("DELETE FROM cards WHERE id = ?", id)
	if err != nil {
		return fmt.Errorf("failed to delete card: %w", err)
	}
	return nil
}

// ToggleCard toggles the enabled status of a card.
func ToggleCard(id int) error {
	_, err := database.DB.Exec("UPDATE cards SET enabled = CASE WHEN enabled = 1 THEN 0 ELSE 1 END WHERE id = ?", id)
	if err != nil {
		return fmt.Errorf("failed to toggle card: %w", err)
	}
	return nil
}

// MoveCardUp swaps the sort value of the card with the one above it.
func MoveCardUp(id int) error {
	// Get the current card
	card, err := GetCardByID(id)
	if err != nil || card == nil {
		return fmt.Errorf("card not found: %d", id)
	}

	// Find the card with the next lower sort value (the one above)
	var aboveCard Card
	var aboveEnabled int
	err = database.DB.QueryRow(
		"SELECT id, icon, title, subtitle, url, sort, enabled, created_at FROM cards WHERE sort < ? ORDER BY sort DESC LIMIT 1",
		card.Sort,
	).Scan(&aboveCard.ID, &aboveCard.Icon, &aboveCard.Title, &aboveCard.Subtitle, &aboveCard.URL, &aboveCard.Sort, &aboveEnabled, &aboveCard.CreatedAt)
	if err == sql.ErrNoRows {
		// Already at the top
		return nil
	}
	if err != nil {
		return fmt.Errorf("failed to find card above: %w", err)
	}
	aboveCard.Enabled = aboveEnabled == 1

	// Swap sort values
	_, err = database.DB.Exec("UPDATE cards SET sort = ? WHERE id = ?", aboveCard.Sort, card.ID)
	if err != nil {
		return fmt.Errorf("failed to swap sort (current): %w", err)
	}
	_, err = database.DB.Exec("UPDATE cards SET sort = ? WHERE id = ?", card.Sort, aboveCard.ID)
	if err != nil {
		return fmt.Errorf("failed to swap sort (above): %w", err)
	}

	return nil
}

// MoveCardDown swaps the sort value of the card with the one below it.
func MoveCardDown(id int) error {
	// Get the current card
	card, err := GetCardByID(id)
	if err != nil || card == nil {
		return fmt.Errorf("card not found: %d", id)
	}

	// Find the card with the next higher sort value (the one below)
	var belowCard Card
	var belowEnabled int
	err = database.DB.QueryRow(
		"SELECT id, icon, title, subtitle, url, sort, enabled, created_at FROM cards WHERE sort > ? ORDER BY sort ASC LIMIT 1",
		card.Sort,
	).Scan(&belowCard.ID, &belowCard.Icon, &belowCard.Title, &belowCard.Subtitle, &belowCard.URL, &belowCard.Sort, &belowEnabled, &belowCard.CreatedAt)
	if err == sql.ErrNoRows {
		// Already at the bottom
		return nil
	}
	if err != nil {
		return fmt.Errorf("failed to find card below: %w", err)
	}
	belowCard.Enabled = belowEnabled == 1

	// Swap sort values
	_, err = database.DB.Exec("UPDATE cards SET sort = ? WHERE id = ?", belowCard.Sort, card.ID)
	if err != nil {
		return fmt.Errorf("failed to swap sort (current): %w", err)
	}
	_, err = database.DB.Exec("UPDATE cards SET sort = ? WHERE id = ?", card.Sort, belowCard.ID)
	if err != nil {
		return fmt.Errorf("failed to swap sort (below): %w", err)
	}

	return nil
}