<?php
declare(strict_types=1);

function lookup_method_id(PDO $pdo, string $table, ?string $code): ?int
{
    if ($code === null || $code === '') {
        return null;
    }

    $stmt = $pdo->prepare("SELECT id FROM public.{$table} WHERE code = :code LIMIT 1");
    $stmt->execute([':code' => $code]);
    $id = $stmt->fetchColumn();

    return $id === false ? null : (int) $id;
}

function map_payment_code(string $input): ?string
{
    $v = strtolower(trim($input));
    if ($v === '') {
        return null;
    }

    if (str_contains($v, 'twint')) {
        return 'twint';
    }
    if (str_contains($v, 'bank') || str_contains($v, 'vorauskasse') || str_contains($v, 'ueberweisung')) {
        return 'bank_transfer';
    }
    if (str_contains($v, 'kredit') || str_contains($v, 'debit') || str_contains($v, 'card')) {
        return 'card';
    }

    return null;
}

function map_shipping_code(string $input): ?string
{
    $v = strtolower(trim($input));
    if ($v === '') {
        return null;
    }

    if (str_contains($v, 'abholung') || str_contains($v, 'pickup')) {
        return 'pickup';
    }
    if (str_contains($v, 'post') || str_contains($v, 'versand')) {
        return 'post_standard';
    }

    return null;
}

function ensure_required_tables_exist(PDO $pdo): void
{
    $required = [
        'party',
        'address',
        'sales_order',
        'sales_order_line',
        'payment_method',
        'shipping_method',
    ];

    $stmt = $pdo->query(
        "SELECT table_name
         FROM information_schema.tables
         WHERE table_schema = 'public'"
    );
    $rows = $stmt->fetchAll(PDO::FETCH_COLUMN);
    $existing = array_map('strval', $rows ?: []);
    $missing = array_values(array_diff($required, $existing));

    if ($missing !== []) {
        throw new RuntimeException('DB schema not initialized. Missing tables: ' . implode(', ', $missing));
    }
}

function find_existing_order_id(PDO $pdo, string $externalRef): ?int
{
    $stmt = $pdo->prepare('SELECT id FROM sales_order WHERE external_ref = :external_ref LIMIT 1');
    $stmt->execute([':external_ref' => $externalRef]);
    $id = $stmt->fetchColumn();

    return $id === false ? null : (int) $id;
}

function upsert_sales_order(PDO $pdo, array $fields): int
{
    $stmt = $pdo->prepare(
        'INSERT INTO public.sales_order (
            external_ref, party_id, order_source, order_status, payment_status, payment_method_id, shipping_method_id,
            amount_net, amount_shipping, amount_tax, amount_discount, total_amount, currency, webhook_payload, imported_at, created_at, updated_at
         ) VALUES (
            :external_ref, :party_id, :order_source, :order_status, :payment_status, :payment_method_id, :shipping_method_id,
            :amount_net, :amount_shipping, :amount_tax, :amount_discount, :total_amount, :currency, :webhook_payload::jsonb, NOW(), NOW(), NOW()
         )
         ON CONFLICT (external_ref) DO UPDATE SET
            party_id = EXCLUDED.party_id,
            order_source = EXCLUDED.order_source,
            order_status = EXCLUDED.order_status,
            payment_status = EXCLUDED.payment_status,
            payment_method_id = EXCLUDED.payment_method_id,
            shipping_method_id = EXCLUDED.shipping_method_id,
            amount_net = EXCLUDED.amount_net,
            amount_shipping = EXCLUDED.amount_shipping,
            amount_tax = EXCLUDED.amount_tax,
            amount_discount = EXCLUDED.amount_discount,
            total_amount = EXCLUDED.total_amount,
            currency = EXCLUDED.currency,
            webhook_payload = EXCLUDED.webhook_payload,
            imported_at = NOW(),
            updated_at = NOW()
         RETURNING id'
    );
    $stmt->execute($fields);

    $id = $stmt->fetchColumn();
    if ($id === false) {
        throw new RuntimeException('Could not upsert order');
    }

    return (int) $id;
}

function create_direct_sales_order(PDO $pdo, array $fields): array
{
    $stmt = $pdo->prepare(
        "INSERT INTO sales_order (
            external_ref, party_id, order_source, order_status, payment_status, payment_method_id,
            amount_net, amount_shipping, amount_tax, amount_discount, total_amount, currency, imported_at, created_at, updated_at
         ) VALUES (
            '', :party_id, 'direct', 'imported', 'paid', :payment_method_id,
            :amount_net, 0, 0, 0, :total_amount, 'CHF', NOW(), NOW(), NOW()
         )
         RETURNING id, external_ref"
    );
    $stmt->execute($fields);

    $row = $stmt->fetch();
    if ($row === false) {
        throw new RuntimeException('Could not create order');
    }

    return [
        'id' => (int) $row['id'],
        'external_ref' => (string) $row['external_ref'],
    ];
}

function delete_sales_order_lines(PDO $pdo, int $orderId): void
{
    $deleteLines = $pdo->prepare('DELETE FROM public.sales_order_line WHERE sales_order_id = :sales_order_id');
    $deleteLines->execute([':sales_order_id' => $orderId]);
}

function insert_sales_order_line(PDO $pdo, array $fields): int
{
    $stmt = $pdo->prepare(
        'INSERT INTO public.sales_order_line (
            sales_order_id, line_no, sellable_item_id, raw_external_article_number, raw_external_title,
            qty, unit_price, line_total, created_at, updated_at
         ) VALUES (
            :sales_order_id, :line_no, :sellable_item_id, :article_number, :title,
            :qty, :unit_price, :line_total, NOW(), NOW()
         )
         RETURNING id'
    );
    $stmt->execute($fields);

    $id = $stmt->fetchColumn();
    if ($id === false) {
        throw new RuntimeException('Could not insert sales_order_line');
    }

    return (int) $id;
}

function normalize_sales_order_sort_column(string $sortColumn): string
{
    $allowed = [
        'order_date',
        'external_ref',
        'name',
        'total_amount',
    ];

    return in_array($sortColumn, $allowed, true) ? $sortColumn : 'order_date';
}

function normalize_sales_order_sort_direction(string $direction, string $sortColumn): string
{
    $direction = strtoupper(trim($direction));
    if ($direction !== 'ASC' && $direction !== 'DESC') {
        return $sortColumn === 'order_date' ? 'DESC' : 'ASC';
    }

    return $direction;
}

function escape_sales_order_search_term(string $searchTerm): string
{
    return strtr($searchTerm, [
        '\\' => '\\\\',
        '%' => '\\%',
        '_' => '\\_',
    ]);
}

function get_sales_order_overview(PDO $pdo, array $filters = []): array
{
    $searchTerm = trim((string) ($filters['search'] ?? ''));
    $sortColumn = normalize_sales_order_sort_column((string) ($filters['sort_column'] ?? 'order_date'));
    $sortDirection = normalize_sales_order_sort_direction((string) ($filters['sort_direction'] ?? ''), $sortColumn);
    $limit = max(1, (int) ($filters['limit'] ?? 20));
    $pageSize = max(1, (int) ($filters['page_size'] ?? 20));

    $filterSql = '';
    $params = [];
    if ($searchTerm !== '') {
        $filterSql = <<<'SQL'
WHERE (
    so.external_ref ILIKE :search_term ESCAPE '\'
    OR so.order_date::text ILIKE :search_term ESCAPE '\'
    OR COALESCE(so.total_amount::text, '') ILIKE :search_term ESCAPE '\'
    OR COALESCE(ad.last_name, '') ILIKE :search_term ESCAPE '\'
    OR COALESCE(ad.first_name, '') ILIKE :search_term ESCAPE '\'
    OR (COALESCE(ad.first_name, '') || ' ' || COALESCE(ad.last_name, '')) ILIKE :search_term ESCAPE '\'
    OR COALESCE(ad.street, '') ILIKE :search_term ESCAPE '\'
    OR COALESCE(ad.house_number, '') ILIKE :search_term ESCAPE '\'
    OR COALESCE(ad.zip, '') ILIKE :search_term ESCAPE '\'
    OR COALESCE(ad.city, '') ILIKE :search_term ESCAPE '\'
    OR COALESCE(ad.country_name, '') ILIKE :search_term ESCAPE '\'
)
SQL;
        $params[':search_term'] = '%' . escape_sales_order_search_term($searchTerm) . '%';
    }

    $sortExpressions = [
        'order_date' => 'so.order_date',
        'external_ref' => 'so.external_ref',
        'name' => 'COALESCE(ad.first_name, \'\') || \' \' || COALESCE(ad.last_name, \'\')',
        'total_amount' => 'COALESCE(so.total_amount, 0)',
    ];
    $sortExpression = $sortExpressions[$sortColumn] ?? 'so.order_date';

    $baseFromSql = <<<'SQL'
FROM sales_order so
LEFT JOIN LATERAL (
    SELECT
        a.first_name,
        a.last_name,
        a.street,
        a.house_number,
        a.zip,
        a.city,
        a.country_name
    FROM address a
    WHERE a.party_id = so.party_id
      AND a.type = 'shipping'
    ORDER BY a.id DESC
    LIMIT 1
) ad ON TRUE
SQL;

    $countStmt = $pdo->prepare(
        'SELECT COUNT(*) ' . $baseFromSql . "\n" . $filterSql
    );
    foreach ($params as $key => $value) {
        $countStmt->bindValue($key, $value, PDO::PARAM_STR);
    }
    $countStmt->execute();
    $totalCount = (int) $countStmt->fetchColumn();

    $listSql = <<<'SQL'
SELECT
    so.id,
    so.external_ref,
    so.order_date,
    so.total_amount,
    COALESCE(ad.first_name, '') AS first_name,
    COALESCE(ad.last_name, '') AS last_name,
    COALESCE(ad.street, '') AS street,
    COALESCE(ad.house_number, '') AS house_number,
    COALESCE(ad.zip, '') AS zip,
    COALESCE(ad.city, '') AS city,
    COALESCE(ad.country_name, '') AS country_name
SQL;
    $listSql .= "\n" . $baseFromSql . "\n" . $filterSql;
    $listSql .= "\nORDER BY {$sortExpression} {$sortDirection}, so.id {$sortDirection}";
    $listSql .= "\nLIMIT :limit";

    $listStmt = $pdo->prepare($listSql);
    foreach ($params as $key => $value) {
        $listStmt->bindValue($key, $value, PDO::PARAM_STR);
    }
    $listStmt->bindValue(':limit', $limit, PDO::PARAM_INT);
    $listStmt->execute();

    $rows = [];
    foreach ($listStmt->fetchAll() as $row) {
        $rows[] = [
            'id' => (int) $row['id'],
            'external_ref' => (string) $row['external_ref'],
            'order_date' => (string) $row['order_date'],
            'total_amount' => $row['total_amount'] !== null ? (float) $row['total_amount'] : null,
            'first_name' => (string) $row['first_name'],
            'last_name' => (string) $row['last_name'],
            'street' => (string) $row['street'],
            'house_number' => (string) $row['house_number'],
            'zip' => (string) $row['zip'],
            'city' => (string) $row['city'],
            'country_name' => (string) $row['country_name'],
        ];
    }

    return [
        'rows' => $rows,
        'search' => $searchTerm,
        'sort_column' => $sortColumn,
        'sort_direction' => $sortDirection,
        'limit' => $limit,
        'page_size' => $pageSize,
        'total_count' => $totalCount,
        'has_more' => $totalCount > $limit,
        'next_limit' => min($totalCount, $limit + $pageSize),
    ];
}