<?php
/**
 * Settings Migration for Easy Invoice
 *
 * @package     EasyInvoice
 * @subpackage  Migration
 * @since       2.0.0
 */

namespace EasyInvoice\Migration\Src;

/**
 * Settings migration class.
 *
 * Handles migration of all plugin settings and options.
 *
 * @since 2.0.0
 */
class SettingsMigration extends AbstractMigration implements MigrationInterface {

    /**
     * Migration description.
     *
     * @since 2.0.0
     * @var string
     */
    protected $description = 'Migrate plugin settings and options to new structure';

    /**
     * Simple settings mapping: old option ID => new option ID
     *
     * @since 2.0.0
     * @var array
     */
    protected $settings_mapping = [

        // Company settings - these exist in the plugin
        'easy_invoice_business_logo' => 'easy_invoice_company_logo',
        'easy_invoice_business_name' => 'easy_invoice_company_name',
        'easy_invoice_business_address' => 'easy_invoice_company_address',
        'easy_invoice_business_website_url' => 'easy_invoice_company_website',
        'easy_invoice_business_additional_info' => 'easy_invoice_company_additional_info',
        'easy_invoice_business_phone' => 'easy_invoice_company_phone',
        'easy_invoice_business_email' => 'easy_invoice_company_email',
        'easy_invoice_business_vat' => 'easy_invoice_tax_number',
        'easy_invoice_company_phone' => 'easy_invoice_company_phone',
        'easy_invoice_company_email' => 'easy_invoice_company_email',
        'easy_invoice_company_additional_info' => 'easy_invoice_company_additional_info',

        // Email settings - these exist in the plugin
        'easy_invoice_email_from_address' => 'easy_invoice_email_from_address',
        'easy_invoice_email_from_name' => 'easy_invoice_email_from_name',
        'easy_invoice_email_send_admin_copy' => 'easy_invoice_bcc_admin',
        'easy_invoice_email_reply_to' => 'easy_invoice_email_reply_to',
        'easy_invoice_email_reply_to_name' => 'easy_invoice_email_reply_to_name',
        'easy_invoice_email_logo' => 'easy_invoice_email_logo',
        'easy_invoice_email_footer_text' => 'easy_invoice_email_footer_text',
        'easy_invoice_enable_email_styling' => 'easy_invoice_enable_email_styling',
        'easy_invoice_admin_email' => 'easy_invoice_admin_email',
        'easy_invoice_test_email' => 'easy_invoice_test_email',

        // Invoice settings - these exist in the plugin
        'easy_invoice_number_prefix' => 'easy_invoice_invoice_prefix',
        'easy_invoice_invoice_number' => 'easy_invoice_invoice_starting_number',
        'easy_invoice_show_hide_adjust' => 'easy_invoice_invoice_show_adjust_field',
        'easy_invoice_terms_conditions' => 'easy_invoice_invoice_terms_conditions',
        'easy_invoice_footer_text' => 'easy_invoice_invoice_footer_text',

        // Quote settings - these exist in the plugin
        'easy_invoice_quote_number_prefix' => 'easy_invoice_quote_prefix',
        'easy_invoice_quote_number' => 'easy_invoice_quote_starting_number',
        'easy_invoice_quote_show_hide_adjust' => 'easy_invoice_quote_show_adjust_field',
        'easy_invoice_quote_terms_conditions' => 'easy_invoice_quote_terms_conditions',
        'easy_invoice_quote_footer_text' => 'easy_invoice_quote_footer_text',
        'easy_invoice_quote_accept_quote_button' => 'easy_invoice_quote_accept_button',
        'easy_invoice_quote_accept_quote_button_action' => 'easy_invoice_quote_accept_action',
        'easy_invoice_accept_quote_text' => 'easy_invoice_quote_accept_text',
        'easy_invoice_accepted_quote_message' => 'easy_invoice_quote_accepted_message',
        'easy_invoice_decline_quote_reason_required' => 'easy_invoice_quote_decline_reason_required',
        'easy_invoice_declined_quote_message' => 'easy_invoice_quote_declined_message',

        // Currency settings - these exist in the plugin
        'easy_invoice_currency' => 'easy_invoice_currency_code',
        'easy_invoice_currency_symbol_type' => 'easy_invoice_currency_symbol_type',
        'easy_invoice_currency_position' => 'easy_invoice_currency_position',
        'easy_invoice_thousand_separator' => 'easy_invoice_thousands_separator',
        'easy_invoice_decimal_separator' => 'easy_invoice_decimal_separator',
        'easy_invoice_price_number_decimals' => 'easy_invoice_decimal_precision',

        // Tax settings - these exist in the plugin
        'easy_invoice_tax_type' => 'easy_invoice_tax_entry_method',
        'easy_invoice_tax_percentage' => 'easy_invoice_tax_rate',

        // Payment settings - these exist in the plugin
        'easy_invoice_payment_methods' => 'easy_invoice_payment_methods',
        'easy_invoice_payment_gateway_order' => 'easy_invoice_payment_gateway_order',
        'easy_invoice_payment_email_enabled' => 'easy_invoice_payment_email_enabled',
        'easy_invoice_payment_email_subject' => 'easy_invoice_payment_email_subject',
        'easy_invoice_payment_email_body' => 'easy_invoice_payment_email_body',
        'easy_invoice_payment_reminder_days' => 'easy_invoice_payment_reminder_days',
        'easy_invoice_payment_terms' => 'easy_invoice_payment_terms',

        // Additional settings that might exist
        'easy_invoice_pre_defined_line_items' => 'easy_invoice_pre_defined_line_items',
        'easy_invoice_client_portal_enabled' => 'easy_invoice_client_portal_enabled',
        'easy_invoice_client_registration_enabled' => 'easy_invoice_client_registration_enabled',
        'easy_invoice_client_login_redirect' => 'easy_invoice_client_login_redirect',
        'easy_invoice_client_registration_redirect' => 'easy_invoice_client_registration_redirect',
    ];

    /**
     * Check if migration is needed.
     *
     * @since 2.0.0
     * @return bool
     */
    public function is_needed(): bool {
        // Check if settings have already been migrated
        if (get_option('easy_invoice_settings_migrated', false)) {
            return false;
        }

        // Check if any old settings exist
        foreach ($this->settings_mapping as $old_key => $new_key) {
            if ($this->option_exists($old_key)) {
                $this->log(sprintf('Found setting %s that needs migration', $old_key));
                return true;
            }
        }

        return false;
    }

    /**
     * Run the migration.
     *
     * @since 2.0.0
     * @return array
     */
    public function migrate(): array {
        $this->log('Starting settings migration');

        try {
            $migrated_count = 0;
            $errors = [];

            // Simple migration: copy data from old options to new options
            foreach ($this->settings_mapping as $old_key => $new_key) {
                try {
                    $old_value = get_option($old_key);
                    if ($old_value !== false) {
                        // Transform the value if needed
                        $transformed_value = $this->transform_setting_value($old_key, $old_value);

                        // Copy the transformed value to new option
                        update_option($new_key, $transformed_value);

                        // Delete old option
                        //delete_option($old_key);

                        $migrated_count++;
                        $this->log(sprintf('Successfully migrated setting %s to %s (value: %s)', $old_key, $new_key, var_export($transformed_value, true)));
                    }
                } catch (\Exception $e) {
                    $errors[] = sprintf('Failed to migrate setting %s: %s', $old_key, $e->getMessage());
                    $this->log(sprintf('Failed to migrate setting %s: %s', $old_key, $e->getMessage()), 'error');
                }
            }

            // Special handling for payment gateways
            $this->migrate_payment_gateways();

            if (empty($errors)) {
                // Set a flag to indicate settings migration is complete
                update_option('easy_invoice_settings_migrated', true);
                return $this->success_result(sprintf('Successfully migrated %d settings', $migrated_count));
            } else {
                return $this->error_result('Settings migration completed with errors: ' . implode(', ', $errors));
            }

        } catch (\Exception $e) {
            $this->log('Settings migration failed: ' . $e->getMessage(), 'error');
            return $this->error_result('Settings migration failed: ' . $e->getMessage());
        }
    }

    /**
     * Check if an option exists.
     *
     * @since 2.0.0
     * @param string $option Option name
     * @return bool
     */
    protected function option_exists(string $option): bool {
        return get_option($option) !== false;
    }

    /**
     * Transform setting value based on the setting type.
     *
     * @since 2.0.0
     * @param string $old_key Old setting key
     * @param mixed $value Setting value
     * @return mixed Transformed value
     */
    protected function transform_setting_value(string $old_key, $value) {
        // Handle tax_type transformation
        if ($old_key === 'easy_invoice_tax_type') {
            return $value === 'inclusive' ? 'yes' : 'no';
        }

        // Handle tax_percentage - ensure it's numeric
        if ($old_key === 'easy_invoice_tax_percentage') {
            return floatval($value);
        }

        // Handle number fields - ensure they're numeric
        if (in_array($old_key, [
            'easy_invoice_invoice_number',
            'easy_invoice_quote_number',
            'easy_invoice_price_number_decimals'
        ])) {
            return intval($value);
        }

        // Handle checkbox fields - ensure they're boolean strings
        if (in_array($old_key, [
            'easy_invoice_show_hide_adjust',
            'easy_invoice_quote_show_hide_adjust',
            'easy_invoice_quote_accept_quote_button',
            'easy_invoice_decline_quote_reason_required',
            'easy_invoice_payment_gateway_test_mode',
            'easy_invoice_enable_proceed_to_payment'
        ])) {
            return $value ? 'yes' : 'no';
        }

        // Handle payment gateways - ensure it's an array
        if ($old_key === 'easy_invoice_payment_gateways') {
            if (is_array($value)) {
                return $value;
            } elseif (is_string($value)) {
                // If it's a serialized string, unserialize it
                $unserialized = maybe_unserialize($value);
                return is_array($unserialized) ? $unserialized : [];
            }
            return [];
        }

        // Default: return value as-is
        return $value;
    }

    /**
     * Migrate payment gateways with special handling.
     *
     * @since 2.0.0
     * @return void
     */
    protected function migrate_payment_gateways(): void {
        $this->log('Starting payment gateways migration');

        // Get old payment gateways
        $old_gateways = get_option('easy_invoice_payment_gateways', []);
        if (empty($old_gateways)) {
            $this->log('No payment gateways found to migrate');
            return;
        }

        // Transform old gateway format to new format
        $new_gateways = [];
        foreach ($old_gateways as $gateway_id => $enabled) {
            if ($enabled) {
                $new_gateways[] = $gateway_id;
            }
        }

        // Save new payment gateways
        if (!empty($new_gateways)) {
            update_option('easy_invoice_payment_methods', $new_gateways);
            $this->log(sprintf('Migrated payment gateways: %s', implode(', ', $new_gateways)));
        }

        // Handle individual gateway settings
        $this->migrate_individual_gateway_settings();
    }

    /**
     * Migrate individual gateway settings.
     *
     * @since 2.0.0
     * @return void
     */
    protected function migrate_individual_gateway_settings(): void {
        // Common gateway settings that might exist
        $gateway_settings = [
            'easy_invoice_paypal_enabled' => 'easy_invoice_paypal_enabled',
            'easy_invoice_stripe_enabled' => 'easy_invoice_stripe_enabled',
            'easy_invoice_bank_transfer_enabled' => 'easy_invoice_bank_transfer_enabled',
            'easy_invoice_cash_enabled' => 'easy_invoice_cash_enabled',
            'easy_invoice_cheque_enabled' => 'easy_invoice_cheque_enabled',
        ];

        foreach ($gateway_settings as $old_key => $new_key) {
            $old_value = get_option($old_key);
            if ($old_value !== false) {
                $transformed_value = $this->transform_setting_value($old_key, $old_value);
                update_option($new_key, $transformed_value);
                $this->log(sprintf('Migrated gateway setting %s to %s', $old_key, $new_key));
            }
        }
    }
}