<?php
/**
 * This file is part of Rollora – Made-to-Measure Roller Blinds.
 * It is free software, licensed under GPL-2.0-or-later. See license.txt.
 * Blinds supplier configuration admin page (roller blinds only).
 *
 * WP-ONLY code: requires WordPress (admin_menu, get_option, nonces,
 * capability checks). It is intentionally NOT covered by the pure-PHP
 * test suite in tests/ — see the limitation note in the handoff.
 *
 * This file registers its hooks on load (guarded by function_exists so
 * a plain require_once outside WordPress does not fatal). The parent
 * plugin file loads it with:
 *   require_once BLINDS_PROTO_DIR . 'includes/class-blinds-admin.php';
 * placed AFTER the pricing-engine and importer requires. Load order
 * versus the main file does not matter for config: this file never
 * calls blinds_proto_load_config(). It reads the JSON defaults directly
 * from ../data/synthetic-supplier.json as a fallback and prefers the
 * wp_option 'blinds_supplier_config' when present and valid.
 *
 * Menu: submenu under the existing 'blinds-proto-import' menu
 * (registered by the main plugin file — never re-registered here).
 * Page slug: 'blinds-proto-settings'. Capability: manage_options.
 * Every save/restore action is capability-checked and nonce-verified.
 * Money is stored in integer minor units; measurements in mm.
 * No file writes outside wp_options. No eval.
 */

declare(strict_types=1);

if ( ! defined( 'ABSPATH' ) ) {
    exit;
}

/**
 * Return the effective supplier configuration.
 *
 * Prefers the wp_option 'blinds_supplier_config' when it is a non-empty
 * array; otherwise falls back to the JSON defaults file. The parent
 * plugin file may switch blinds_proto_load_config() to call this
 * function — that switch is the parent's change, not made here.
 */
function blinds_get_supplier_config(): array
{
    if (function_exists('get_option')) {
        $stored = get_option('blinds_supplier_config');
        if (is_array($stored) && $stored !== []) {
            return $stored;
        }
    }
    return blinds_admin_load_json_defaults();
}

/**
 * Load the synthetic JSON defaults directly from disk.
 * Used as fallback and by "Restore synthetic defaults".
 */
function blinds_admin_load_json_defaults(): array
{
    $path = plugin_dir_path(__FILE__) . '../data/synthetic-supplier.json';
    if (!is_readable($path)) {
        return [];
    }
    $json = file_get_contents($path);
    if ($json === false) {
        return [];
    }
    $config = json_decode($json, true);
    return is_array($config) ? $config : [];
}

/** Sanitised POST text field (wp_unslash + sanitize_text_field). */
function blinds_admin_post_text(string $key): string
{
    if (!isset($_POST[$key])) {
        return '';
    }
    return sanitize_text_field(wp_unslash($_POST[$key]));
}

/** Sanitised POST integer field (absint; mm values and minor units). */
function blinds_admin_post_int(string $key): int
{
    if (!isset($_POST[$key])) {
        return 0;
    }
    return absint($_POST[$key]);
}

/** Sanitised POST textarea field (wp_unslash + sanitize_textarea_field, keeps newlines). */
function blinds_admin_post_textarea(string $key): string
{
    if (!isset($_POST[$key])) {
        return '';
    }
    return sanitize_textarea_field(wp_unslash($_POST[$key]));
}

/**
 * Parse the "Fabric name|roll width mm" textarea into
 * ['Fabric name' => mm, ...]. Lines without a valid mm value are skipped.
 */
function blinds_admin_parse_fabrics(string $raw): array
{
    $out = [];
    foreach (preg_split("/\r\n|\n|\r/", $raw) as $line) {
        $line = trim($line);
        if ($line === '') {
            continue;
        }
        $parts = explode('|', $line, 2);
        $name = sanitize_text_field(trim($parts[0]));
        $mm = isset($parts[1]) ? absint(trim($parts[1])) : 0;
        if ($name !== '' && $mm > 0) {
            $out[$name] = $mm;
        }
    }
    return $out;
}

/**
 * Build the config array to save from POST data, starting from the
 * current config so keys this page does not edit (price_matrix,
 * width_bands, drop_bands, pricing_mode, synthetic_test_rules_source,
 * and per-option fields such as requires / max_width_mm / max_drop_mm)
 * are preserved untouched.
 */
function blinds_admin_build_config_from_post(array $current): array
{
    $config = $current;

    $config['supplier_label'] = blinds_admin_post_text('blinds_supplier_label');
    $currency = strtoupper(blinds_admin_post_text('blinds_currency'));
    if ($currency !== '') {
        $config['currency'] = substr($currency, 0, 3);
    }

    // Data label: only ever changed by an explicit admin edit of this
    // field. It is NEVER auto-changed by saving, restoring, or loading.
    // Default 'SYNTHETIC' until the admin replaces the defaults with
    // real supplier values and explicitly sets this label themselves.
    $label = blinds_admin_post_text('blinds_data_label');
    if ($label !== '') {
        $config['data_label'] = $label;
    } elseif (!isset($config['data_label'])) {
        $config['data_label'] = 'SYNTHETIC';
    }

    $config['deductions'] = [
        'recess' => [
            'width_mm' => blinds_admin_post_int('blinds_deduction_recess_width'),
            'drop_mm' => blinds_admin_post_int('blinds_deduction_recess_drop'),
        ],
        'exact' => [
            'width_mm' => blinds_admin_post_int('blinds_deduction_exact_width'),
            'drop_mm' => blinds_admin_post_int('blinds_deduction_exact_drop'),
        ],
    ];
    $config['corner_deduction'] = [
        'width_mm' => blinds_admin_post_int('blinds_corner_width'),
        'drop_mm' => blinds_admin_post_int('blinds_corner_drop'),
        'drop_over_mm' => blinds_admin_post_int('blinds_corner_drop_over'),
    ];
    $config['mechanism_allowance_mm'] = blinds_admin_post_int('blinds_mechanism_allowance');
    $config['limits'] = [
        'min_overall_width_mm' => blinds_admin_post_int('blinds_limit_min_width'),
        'max_overall_width_mm' => blinds_admin_post_int('blinds_limit_max_width'),
        'min_overall_drop_mm' => blinds_admin_post_int('blinds_limit_min_drop'),
        'max_overall_drop_mm' => blinds_admin_post_int('blinds_limit_max_drop'),
    ];
    $config['roll_width_mm'] = blinds_admin_post_int('blinds_roll_width_default');
    $fabrics = blinds_admin_parse_fabrics(blinds_admin_post_textarea('blinds_fabrics'));
    if ($fabrics !== []) {
        $config['roll_widths_by_fabric'] = $fabrics;
    }
    $config['outside_mount_additions'] = [
        'width_mm' => blinds_admin_post_int('blinds_outside_width'),
        'drop_mm' => blinds_admin_post_int('blinds_outside_drop'),
    ];
    $config['recess_depth_min_mm'] = blinds_admin_post_int('blinds_recess_depth_min');
    $config['tolerance_mm'] = [
        'width_mm' => blinds_admin_post_int('blinds_tolerance_width'),
        'drop_mm' => blinds_admin_post_int('blinds_tolerance_drop'),
    ];
    $config['min_charge_minor'] = blinds_admin_post_int('blinds_min_charge_minor');

    // Options: edit existing options in place (code is the key and is
    // never changed from the form), preserving unedited per-option
    // fields. One optional new option row is added only when its code
    // is non-empty and not already present.
    $postedOptions = isset($_POST['blinds_options']) && is_array($_POST['blinds_options'])
        ? wp_unslash($_POST['blinds_options'])
        : [];
    $existing = [];
    foreach (($current['options'] ?? []) as $opt) {
        if (isset($opt['code'])) {
            $existing[(string) $opt['code']] = $opt;
        }
    }
    $saved = [];
    foreach ($postedOptions as $row) {
        if (!is_array($row)) {
            continue;
        }
        $code = isset($row['code']) ? sanitize_text_field((string) $row['code']) : '';
        if ($code === '' || !isset($existing[$code])) {
            continue;
        }
        $opt = $existing[$code];
        if (isset($row['label'])) {
            $opt['label'] = sanitize_text_field((string) $row['label']);
        }
        if (isset($row['shape'])) {
            $shape = sanitize_text_field((string) $row['shape']);
            if (in_array($shape, ['flat_per_blind', 'flat_per_order', 'per_m2', 'percent', 'width_banded', 'quote_only'], true)) {
                $opt['shape'] = $shape;
            }
        }
        if (isset($row['amount_minor'])) {
            // Money stays integer minor units. A per-m2 rate that needs
            // decimals must be expressed in minor units per m2 here;
            // floatval is used only to normalise the input before it
            // is cast back to an integer — no fractional money is stored.
            $opt['amount_minor'] = (int) floatval($row['amount_minor']);
            if ($opt['amount_minor'] < 0) {
                $opt['amount_minor'] = 0;
            }
        }
        if (isset($row['workshop_part'])) {
            $opt['workshop_part'] = sanitize_text_field((string) $row['workshop_part']);
        }
        $saved[] = $opt;
        unset($existing[$code]);
    }
    // Keep any existing option not present in the posted rows.
    foreach ($existing as $opt) {
        $saved[] = $opt;
    }
    $newCode = blinds_admin_post_text('blinds_new_option_code');
    if ($newCode !== '') {
        $codes = array_column($saved, 'code');
        if (!in_array($newCode, $codes, true)) {
            $newShape = blinds_admin_post_text('blinds_new_option_shape');
            if (!in_array($newShape, ['flat_per_blind', 'flat_per_order', 'per_m2', 'percent', 'width_banded', 'quote_only'], true)) {
                $newShape = 'flat_per_blind';
            }
            $saved[] = [
                'code' => $newCode,
                'label' => blinds_admin_post_text('blinds_new_option_label'),
                'shape' => $newShape,
                'amount_minor' => blinds_admin_post_int('blinds_new_option_amount'),
                'workshop_part' => blinds_admin_post_text('blinds_new_option_part'),
            ];
        }
    }
    $config['options'] = $saved;

    // Version stamp: incremented integer, author, timestamp.
    $config['config_version'] = (int) ($current['config_version'] ?? 0) + 1;
    $config['updated_by'] = function_exists('get_current_user_id') ? get_current_user_id() : 0;
    $config['updated_at'] = function_exists('current_time') ? current_time('mysql') : gmdate('Y-m-d H:i:s');

    return $config;
}

/** Render the settings page. Handles save and restore before output. */
function blinds_admin_render_settings_page(): void
{
    if (!current_user_can('manage_options')) {
        return;
    }
    $notice = '';
    $config = blinds_get_supplier_config();

    if (!empty($_POST['blinds_supplier_save'])) {
        $nonce = isset($_POST['blinds_supplier_config_nonce']) ? sanitize_text_field(wp_unslash($_POST['blinds_supplier_config_nonce'])) : '';
        if (!wp_verify_nonce($nonce, 'blinds_supplier_config_save')) {
            $notice = 'Settings not saved: security check failed.';
        } else {
            $saved = blinds_admin_build_config_from_post($config);
            update_option('blinds_supplier_config', $saved);
            $config = $saved;
            $notice = 'Supplier configuration saved (version ' . (int) $saved['config_version'] . ').';
        }
    } elseif (!empty($_POST['blinds_supplier_restore'])) {
        $nonce = isset($_POST['blinds_supplier_restore_nonce']) ? sanitize_text_field(wp_unslash($_POST['blinds_supplier_restore_nonce'])) : '';
        if (!wp_verify_nonce($nonce, 'blinds_supplier_config_restore')) {
            $notice = 'Defaults not restored: security check failed.';
        } else {
            $defaults = blinds_admin_load_json_defaults();
            $defaults['config_version'] = (int) ($config['config_version'] ?? 0) + 1;
            $defaults['updated_by'] = function_exists('get_current_user_id') ? get_current_user_id() : 0;
            $defaults['updated_at'] = function_exists('current_time') ? current_time('mysql') : gmdate('Y-m-d H:i:s');
            update_option('blinds_supplier_config', $defaults);
            $config = $defaults;
            $notice = 'Synthetic defaults restored. Data label is SYNTHETIC until you replace these values with real supplier values and explicitly change the label.';
        }
    }

    $deductions = $config['deductions'] ?? [];
    $limits = $config['limits'] ?? [];
    $corner = $config['corner_deduction'] ?? [];
    $tolerance = $config['tolerance_mm'] ?? [];
    $outside = $config['outside_mount_additions'] ?? [];
    $fabrics = $config['roll_widths_by_fabric'] ?? [];
    $fabricLines = '';
    foreach ($fabrics as $name => $mm) {
        $fabricLines .= $name . '|' . (int) $mm . "\n";
    }
    $shapes = ['flat_per_blind', 'flat_per_order', 'per_m2', 'percent', 'width_banded', 'quote_only'];

    echo '<div class="wrap blinds-admin-wrap"><h1>Rollora — Supplier Configuration (Roller Only)</h1>';
    if ($notice !== '') {
        echo '<div class="notice notice-success"><p>' . esc_html($notice) . '</p></div>';
    }
    echo '<p>Data label: <strong>' . esc_html((string) ($config['data_label'] ?? 'SYNTHETIC')) . '</strong>. ';
    echo 'These are SYNTHETIC defaults until you replace them with real supplier values. ';
    echo 'Change the data label below ONLY when you have done so — it is never changed automatically. ';
    echo 'Money is stored in integer minor units; all measurements are in millimetres. ';
    echo 'Price matrix and width/drop bands are edited through the CSV importer, not on this page, and are preserved unchanged when you save here.</p>';
    if (!empty($config['config_version'])) {
        echo '<p>Config version: ' . esc_html((string) $config['config_version']) . '. Last updated: ' . esc_html((string) ($config['updated_at'] ?? '')) . '.</p>';
    }
    echo '<form method="post" class="blinds-admin-form">';
    wp_nonce_field('blinds_supplier_config_save', 'blinds_supplier_config_nonce');
    echo '<div class="blinds-field-grid">';
    echo '<label>Supplier label <input type="text" name="blinds_supplier_label" value="' . esc_attr((string) ($config['supplier_label'] ?? '')) . '"></label>';
    echo '<label>Currency (3-letter code) <input type="text" name="blinds_currency" value="' . esc_attr((string) ($config['currency'] ?? 'GBP')) . '" maxlength="3"></label>';
    echo '<label>Data label (change ONLY when real supplier values replace the defaults) <input type="text" name="blinds_data_label" value="' . esc_attr((string) ($config['data_label'] ?? 'SYNTHETIC')) . '"></label>';
    echo '<label>Minimum charge (minor units) <input type="number" name="blinds_min_charge_minor" min="0" value="' . esc_attr((string) ($config['min_charge_minor'] ?? 0)) . '"></label>';
    echo '<label>Recess deduction, width (mm) <input type="number" name="blinds_deduction_recess_width" min="0" value="' . esc_attr((string) ($deductions['recess']['width_mm'] ?? 0)) . '"></label>';
    echo '<label>Recess deduction, drop (mm) <input type="number" name="blinds_deduction_recess_drop" min="0" value="' . esc_attr((string) ($deductions['recess']['drop_mm'] ?? 0)) . '"></label>';
    echo '<label>Exact deduction, width (mm) <input type="number" name="blinds_deduction_exact_width" min="0" value="' . esc_attr((string) ($deductions['exact']['width_mm'] ?? 0)) . '"></label>';
    echo '<label>Exact deduction, drop (mm) <input type="number" name="blinds_deduction_exact_drop" min="0" value="' . esc_attr((string) ($deductions['exact']['drop_mm'] ?? 0)) . '"></label>';
    echo '<label>Corner deduction, width (mm) <input type="number" name="blinds_corner_width" min="0" value="' . esc_attr((string) ($corner['width_mm'] ?? 0)) . '"></label>';
    echo '<label>Corner deduction, drop (mm) <input type="number" name="blinds_corner_drop" min="0" value="' . esc_attr((string) ($corner['drop_mm'] ?? 0)) . '"></label>';
    echo '<label>Corner deduction applies when drop exceeds (mm) <input type="number" name="blinds_corner_drop_over" min="0" value="' . esc_attr((string) ($corner['drop_over_mm'] ?? 0)) . '"></label>';
    echo '<label>Mechanism allowance (mm) <input type="number" name="blinds_mechanism_allowance" min="0" value="' . esc_attr((string) ($config['mechanism_allowance_mm'] ?? 0)) . '"></label>';
    echo '<label>Minimum overall width (mm) <input type="number" name="blinds_limit_min_width" min="0" value="' . esc_attr((string) ($limits['min_overall_width_mm'] ?? 0)) . '"></label>';
    echo '<label>Maximum overall width (mm) <input type="number" name="blinds_limit_max_width" min="0" value="' . esc_attr((string) ($limits['max_overall_width_mm'] ?? 0)) . '"></label>';
    echo '<label>Minimum overall drop (mm) <input type="number" name="blinds_limit_min_drop" min="0" value="' . esc_attr((string) ($limits['min_overall_drop_mm'] ?? 0)) . '"></label>';
    echo '<label>Maximum overall drop (mm) <input type="number" name="blinds_limit_max_drop" min="0" value="' . esc_attr((string) ($limits['max_overall_drop_mm'] ?? 0)) . '"></label>';
    echo '<label>Default roll width (mm) <input type="number" name="blinds_roll_width_default" min="0" value="' . esc_attr((string) ($config['roll_width_mm'] ?? 0)) . '"></label>';
    echo '<label>Outside-mount addition, width (mm) <input type="number" name="blinds_outside_width" min="0" value="' . esc_attr((string) ($outside['width_mm'] ?? 0)) . '"></label>';
    echo '<label>Outside-mount addition, drop (mm) <input type="number" name="blinds_outside_drop" min="0" value="' . esc_attr((string) ($outside['drop_mm'] ?? 0)) . '"></label>';
    echo '<label>Recess depth minimum (mm) <input type="number" name="blinds_recess_depth_min" min="0" value="' . esc_attr((string) ($config['recess_depth_min_mm'] ?? 0)) . '"></label>';
    echo '<label>Tolerance, width (mm) <input type="number" name="blinds_tolerance_width" min="0" value="' . esc_attr((string) ($tolerance['width_mm'] ?? 0)) . '"></label>';
    echo '<label>Tolerance, drop (mm) <input type="number" name="blinds_tolerance_drop" min="0" value="' . esc_attr((string) ($tolerance['drop_mm'] ?? 0)) . '"></label>';
    echo '</div>';
    echo '<label>Fabric list — one per line, "Fabric name|roll width mm" <textarea name="blinds_fabrics" rows="5">' . esc_textarea($fabricLines) . '</textarea></label>';
    echo '<h2>Options</h2><p>Amounts are integer minor units. Editing an option here preserves its other fields (such as requires and size gates) unchanged.</p>';
    $index = 0;
    foreach (($config['options'] ?? []) as $opt) {
        echo '<div class="blinds-option-row">';
        echo '<input type="hidden" name="blinds_options[' . $index . '][code]" value="' . esc_attr((string) ($opt['code'] ?? '')) . '">';
        echo '<label>Code <input type="text" value="' . esc_attr((string) ($opt['code'] ?? '')) . '" disabled></label>';
        echo '<label>Label <input type="text" name="blinds_options[' . $index . '][label]" value="' . esc_attr((string) ($opt['label'] ?? '')) . '"></label>';
        echo '<label>Shape <select name="blinds_options[' . $index . '][shape]">';
        foreach ($shapes as $shape) {
            echo '<option value="' . esc_attr($shape) . '"' . selected($shape, (string) ($opt['shape'] ?? ''), false) . '>' . esc_html($shape) . '</option>';
        }
        echo '</select></label>';
        echo '<label>Amount (minor units) <input type="number" name="blinds_options[' . $index . '][amount_minor]" value="' . esc_attr((string) ($opt['amount_minor'] ?? 0)) . '"></label>';
        echo '<label>Workshop part <input type="text" name="blinds_options[' . $index . '][workshop_part]" value="' . esc_attr((string) ($opt['workshop_part'] ?? '')) . '"></label>';
        echo '</div>';
        $index++;
    }
    echo '<h3>Add an option</h3><div class="blinds-option-row">';
    echo '<label>Code <input type="text" name="blinds_new_option_code" value=""></label>';
    echo '<label>Label <input type="text" name="blinds_new_option_label" value=""></label>';
    echo '<label>Shape <select name="blinds_new_option_shape">';
    foreach ($shapes as $shape) {
        echo '<option value="' . esc_attr($shape) . '">' . esc_html($shape) . '</option>';
    }
    echo '</select></label>';
    echo '<label>Amount (minor units) <input type="number" name="blinds_new_option_amount" value="0"></label>';
    echo '<label>Workshop part <input type="text" name="blinds_new_option_part" value=""></label>';
    echo '</div>';
    echo '<p><button type="submit" name="blinds_supplier_save" value="1" class="button button-primary">Save supplier configuration</button></p>';
    echo '</form>';
    echo '<form method="post" onsubmit="return confirm(\'Restore the synthetic defaults? Your edited configuration will be replaced.\');">';
    wp_nonce_field('blinds_supplier_config_restore', 'blinds_supplier_restore_nonce');
    echo '<p><button type="submit" name="blinds_supplier_restore" value="1" class="button">Restore synthetic defaults</button></p>';
    echo '</form></div>';
}

if (function_exists('add_action')) {
    add_action('admin_menu', function () {
        add_submenu_page(
            'blinds-proto-import',
            'Rollora — Supplier Configuration',
            'Supplier Settings',
            'manage_options',
            'blinds-proto-settings',
            'blinds_admin_render_settings_page'
        );
    }, 20);
    add_action('admin_enqueue_scripts', function ($hook) {
        if (strpos((string) $hook, 'blinds-proto-settings') === false) {
            return;
        }
        wp_enqueue_style(
            'blinds-admin',
            plugin_dir_url(__FILE__) . '../assets/admin.css',
            [],
            '1.0.1'
        );
    });
}