<?php

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

class Stacklar_Action_Mail extends Stacklar_Action_Base {

    public function get_action() {
        return 'stacklar_mail';
    }

    public function handle() {
        // The form ID names the nonce action verified right below.
        $form_id = isset( $_POST['stacklar_id'] ) ? absint( $_POST['stacklar_id'] ) : 0; // phpcs:ignore WordPress.Security.NonceVerification.Missing
        if ( ! $form_id ) {
            return $this->json_error( array( 'code' => 'missing_form', 'message' => __( 'Missing form ID.', 'stacklar-forms' ) ), 400 );
        }

        $this->verify_nonce_with( 'stacklar_mail_' . $form_id );

        $post = get_post( $form_id );
        if ( ! $post || $post->post_type !== 'stacklar' ) {
            return $this->json_error( array( 'code' => 'form_not_found', 'message' => __( 'Form not found.', 'stacklar-forms' ) ), 404 );
        }

        $this->enforce_form_protection( $form_id );

        $action_settings = $this->get_server_action_settings_or_fail( $form_id, $this->get_action() );

        $data = $this->collect_post_data( array( 'action', 'stacklar_id', 'entry_id', 'stacklar_entry_token', '_stacklar_nonce', '_wp_http_referer' ) );
        $data = $this->strip_hidden_field_values( $data, $post );
        $label_mode = $this->is_label_key_mode();

        // Field metadata that Stacklar Forms Pro fields post next to their values.
        unset( $data['__stacklar_signature_meta'], $data['stacklar_signature_meta'], $data['__stacklar_rating_meta'], $data['__stacklar_acceptance_meta'], $data['__stacklar_color_meta'], $data['__stacklar_hidden_meta'], $data['__stacklar_address_meta'] );

        $data = $this->merge_tel_helpers( $data );

        $flat_fields_plain = array();
        $flat_fields_html  = array();
        $field_entries     = array();

        foreach ( $data as $key => $value ) {
            $key = sanitize_key( $key );
            if ( '' === $key ) {
                continue;
            }

            $path = $key;
            $display_key = $label_mode ? $this->lookup_label_for_path( $path, $key ) : $key;

            list( $plain_value, $html_value ) = $this->normalise_field_output( $value, $path );

            $flat_fields_plain[ $key ] = $plain_value;
            $flat_fields_html[ $key ]  = $html_value;

            if ( $this->is_tel_helper_key( $key ) ) {
                continue;
            }

            $field_entries[] = array(
                'key'   => $display_key,
                'plain' => $plain_value,
                'html'  => $html_value,
            );
        }

        $all_fields_plain = '';
        if ( ! empty( $field_entries ) ) {
            $lines = array();
            foreach ( $field_entries as $entry ) {
                $lines[] = $entry['key'] . ': ' . $entry['plain'];
            }
            $all_fields_plain = implode( "\n", $lines );
        }

        $all_fields_html = '';
        if ( ! empty( $field_entries ) ) {
            $rows = array();
            foreach ( $field_entries as $entry ) {
                $value_html = $entry['html'] !== '' ? $entry['html'] : '<em>' . esc_html__( 'Empty', 'stacklar-forms' ) . '</em>';
                $rows[] = '<div style="margin:0 0 12px 0;font-size:14px;line-height:1.6;">'
                    . '<strong style="display:block;margin:0 0 4px 0;font-size:13px;">' . esc_html( $entry['key'] ) . ':</strong>'
                    . $value_html
                    . '</div>';
            }
            $all_fields_html = implode( '', $rows );
        }

        $request_context = $this->get_request_context( $form_id );
        $request_token_map = function_exists( 'stacklar_flatten_request_context' ) ? stacklar_flatten_request_context( $request_context ) : array();
        $request_details_plain = '';
        $request_details_html = '';
        if ( ! empty( $request_context ) ) {
            $plain_lines = array();
            $html_rows   = array();
            foreach ( $request_context as $key => $value ) {
                $display_value = function_exists( 'stacklar_request_value_to_string' ) ? stacklar_request_value_to_string( $value ) : ( is_scalar( $value ) ? (string) $value : wp_json_encode( $value ) );
                if ( 'submitted' === $key ) {
                    $timestamp = mysql2date( 'U', $display_value, true );
                    if ( $timestamp ) {
                        $display_value = date_i18n( get_option( 'date_format' ) . ' ' . get_option( 'time_format' ), $timestamp );
                    }
                }

                $plain_lines[] = $key . ': ' . $display_value;
                $html_rows[]   = '<tr>'
                    . '<th scope="row" style="text-align:left;padding:6px 10px;border:1px solid #e2e8f0;background:#f8fafc;">' . esc_html( $key ) . '</th>'
                    . '<td style="padding:6px 10px;border:1px solid #e2e8f0;">' . esc_html( $display_value ) . '</td>'
                    . '</tr>';

                $request_token_map[ 'request_' . $key ] = $display_value;
            }

            if ( ! empty( $plain_lines ) ) {
                $request_details_plain = "Request Details:\n" . implode( "\n", $plain_lines );
                $request_details_html  = '<div style="margin-top:18px;">'
                    . '<h2 style="margin:0 0 10px;font-size:16px;">' . esc_html__( 'Request Details', 'stacklar-forms' ) . '</h2>'
                    . '<table style="width:100%;border-collapse:collapse;border:1px solid #e2e8f0;">' . implode( '', $html_rows ) . '</table>'
                    . '</div>';

                if ( '' !== $all_fields_plain ) {
                    $all_fields_plain .= "\n\n" . $request_details_plain;
                } else {
                    $all_fields_plain = $request_details_plain;
                }

                if ( '' !== $all_fields_html ) {
                    $all_fields_html .= $request_details_html;
                } else {
                    $all_fields_html = $request_details_html;
                }
            }
        }

        $replace_tokens = function( $template, $format = 'text' ) use ( $flat_fields_plain, $flat_fields_html, $form_id, $all_fields_plain, $all_fields_html, $request_token_map, $request_details_plain, $request_details_html ) {
            if ( ! is_string( $template ) || $template === '' ) {
                return '';
            }
            return preg_replace_callback( '/\{\{\s*([a-zA-Z0-9_]+)\s*\}\}/', function ( $matches ) use ( $flat_fields_plain, $flat_fields_html, $form_id, $all_fields_plain, $all_fields_html, $request_token_map, $request_details_plain, $request_details_html, $format ) {
                $token = sanitize_key( $matches[1] );
                if ( 'form_id' === $token ) {
                    return (string) $form_id;
                }
                if ( 'all_fields' === $token ) {
                    return ( 'html' === $format ) ? $all_fields_html : $all_fields_plain;
                }
                if ( 'request_details' === $token ) {
                    if ( '' === $request_details_html && '' === $request_details_plain ) {
                        return '';
                    }
                    if ( 'html' === $format ) {
                        return $request_details_html ? $request_details_html : nl2br( esc_html( $request_details_plain ) );
                    }
                    return $request_details_plain;
                }
                if ( 'request_details_plain' === $token ) {
                    if ( '' === $request_details_plain ) {
                        return '';
                    }
                    return ( 'html' === $format ) ? nl2br( esc_html( $request_details_plain ) ) : $request_details_plain;
                }
                if ( 'request_details_html' === $token ) {
                    if ( '' === $request_details_html ) {
                        return '';
                    }
                    if ( 'html' === $format ) {
                        return $request_details_html;
                    }
                    return wp_strip_all_tags( $request_details_html );
                }
                if ( isset( $request_token_map[ $token ] ) ) {
                    $value = $request_token_map[ $token ];
                    return ( 'html' === $format ) ? esc_html( $value ) : $value;
                }
                if ( 'html' === $format && isset( $flat_fields_html[ $token ] ) ) {
                    return $flat_fields_html[ $token ];
                }
                if ( isset( $flat_fields_plain[ $token ] ) ) {
                    return $flat_fields_plain[ $token ];
                }
                return '';
            }, $template );
        };

        $to_setting = isset( $action_settings['to'] ) ? $action_settings['to'] : '';
        $to_emails  = array();
        if ( is_string( $to_setting ) && $to_setting !== '' ) {
            $parts = array_map( 'trim', explode( ',', $to_setting ) );
            foreach ( $parts as $part ) {
                $email = sanitize_email( $replace_tokens( $part, 'text' ) );
                if ( $email ) {
                    $to_emails[] = $email;
                }
            }
        }
        if ( empty( $to_emails ) ) {
            $default_email = sanitize_email( get_option( 'admin_email' ) );
            if ( $default_email ) {
                $to_emails[] = $default_email;
            }
        }

        /* translators: %d: form ID. */
        $default_subject  = sprintf( __( 'New submission (Form #%d)', 'stacklar-forms' ), $form_id );
        $subject_template = isset( $action_settings['subject'] ) && $action_settings['subject'] !== ''
            ? $action_settings['subject']
            : $default_subject;
        $subject = $replace_tokens( $subject_template, 'text' );
        if ( '' === $subject ) {
            $subject = $default_subject;
        }

        if ( isset( $action_settings['message'] ) && $action_settings['message'] !== '' ) {
            $template = wp_unslash( $action_settings['message'] );
            $template = str_replace( array( "\r\n", "\r" ), "\n", $template );
            $body     = nl2br( $replace_tokens( $template, 'html' ) );
        } else {
            /* translators: %d: form ID. */
            $form_id_line = sprintf( esc_html__( 'Form ID: %d', 'stacklar-forms' ), $form_id );
            $body         = '<p style="margin:0 0 12px 0;">' . $form_id_line . '</p>' . $all_fields_html;
        }

        if ( '' === trim( $body ) ) {
            $body = $all_fields_html ?: '<p>' . esc_html__( 'No data submitted.', 'stacklar-forms' ) . '</p>';
        }

        $headers = array( 'Content-Type: text/html; charset=UTF-8' );
        $reply_to_field = isset( $action_settings['replyto'] ) ? sanitize_key( $action_settings['replyto'] ) : '';
        if ( $reply_to_field && isset( $flat_fields_plain[ $reply_to_field ] ) ) {
            $reply_to_email = sanitize_email( $flat_fields_plain[ $reply_to_field ] );
            if ( $reply_to_email ) {
                $headers[] = 'Reply-To: ' . $reply_to_email;
            }
        }

        $build_message = function( $key, $default ) use ( $action_settings, $replace_tokens ) {
            if ( empty( $action_settings[ $key ] ) ) {
                return $default;
            }
            $template = wp_unslash( (string) $action_settings[ $key ] );
            $value    = $replace_tokens( $template, 'text' );
            $value    = trim( wp_strip_all_tags( $value ) );
            if ( '' === $value ) {
                return $default;
            }
            return $value;
        };

        $success_message = $build_message( 'success_message', __( 'Email has been sent.', 'stacklar-forms' ) );
        $error_message   = $build_message( 'error_message', __( 'Unable to send email.', 'stacklar-forms' ) );

        if ( $this->is_form_test_mode( $form_id ) ) {
            return $this->test_mode_success_response(
                $this->get_action(),
                __( 'Test mode: email was prepared but not sent.', 'stacklar-forms' ),
                array(
                    'prepared' => true,
                )
            );
        }

        if ( ! wp_mail( $to_emails, $subject, $body, $headers ) ) {
            return $this->json_error( array( 'code' => 'mail_failed', 'message' => $error_message ), 500 );
        }

        // Hook for after-mail events if needed
        do_action( 'stacklar_after_mail', $form_id, $data );

        return $this->json_success( array(
            'code'    => 'ok',
            'message' => $success_message,
        ) );
    }

    protected function normalise_field_output( $value, $path = '' ) {
        if ( is_array( $value ) ) {
            return $this->normalise_array_output( $value, $path );
        }

        if ( is_bool( $value ) ) {
            $plain = $value ? '1' : '0';
            return array( $plain, esc_html( $plain ) );
        }

        if ( null === $value ) {
            return array( '', '' );
        }

        if ( is_scalar( $value ) ) {
            $plain = (string) $value;
            $html  = $plain !== '' ? nl2br( esc_html( $plain ) ) : '';
            return array( $plain, $html );
        }

        return array( '', '' );
    }

    /**
     * Normalise array values (repeaters, lists, associative data).
     *
     * @param array $value Raw array value.
     * @return array{string,string}
     */
    protected function normalise_array_output( array $value, $path = '' ) {
        if ( empty( $value ) ) {
            return array( '', '' );
        }

        $empty_text = __( 'Empty', 'stacklar-forms' );
        $empty_html = '<em style="color:rgba(100,116,139,0.9);">' . esc_html( $empty_text ) . '</em>';

        if ( wp_is_numeric_array( $value ) ) {
            if ( $this->all_items_are_assoc( $value ) ) {
                return $this->normalise_repeater_output( $value, $empty_text, $empty_html, $path );
            }
            return $this->normalise_list_output( $value, $empty_text, $empty_html, $path );
        }

        return $this->normalise_assoc_output( $value, $empty_text, $empty_html, $path );
    }

    /**
     * Normalise a list (numeric array) into plain and HTML strings.
     *
     * @param array  $list       List value.
     * @param string $empty_text Placeholder for empty content.
     * @param string $empty_html HTML placeholder for empty content.
     * @return array{string,string}
     */
    protected function normalise_list_output( array $list, $empty_text, $empty_html, $path = '' ) {
        $plain_items = array();
        $html_items  = array();

        foreach ( $list as $index => $item ) {
            $child_path = $path !== '' ? $path . '|' . $index : (string) $index;
            list( $plain, $html ) = $this->normalise_field_output( $item, $child_path );
            if ( '' === $plain ) {
                $plain = $empty_text;
            }
            $plain_items[] = $plain;
            $html_items[]  = '<li>' . ( '' !== $html ? $html : $empty_html ) . '</li>';
        }

        $plain = implode( ', ', array_map( 'trim', $plain_items ) );
        $html  = $html_items ? '<ul style="margin:0;padding-left:18px;">' . implode( '', $html_items ) . '</ul>' : '';

        return array( $plain, $html );
    }

    /**
     * Normalise an associative array.
     *
     * @param array  $assoc      Associative data.
     * @param string $empty_text Placeholder text.
     * @param string $empty_html Placeholder HTML.
     * @return array{string,string}
     */
    protected function normalise_assoc_output( array $assoc, $empty_text, $empty_html, $path = '' ) {
        $plain_lines = array();
        $html_items  = array();

        foreach ( $assoc as $key => $item ) {
            if ( $this->is_tel_helper_key( $key ) ) {
                continue;
            }
            $child_path = $path !== '' ? $path . '|' . $key : (string) $key;
            $label = $this->is_label_key_mode() ? $this->lookup_label_for_path( $child_path, (string) $key ) : (string) $key;
            list( $plain, $html ) = $this->normalise_field_output( $item, $child_path );
            if ( '' === $plain ) {
                $plain = $empty_text;
            }
            $plain_lines[] = $label . ': ' . $plain;
            $html_items[]  = '<li><strong>' . esc_html( $label ) . ':</strong> ' . ( '' !== $html ? $html : $empty_html ) . '</li>';
        }

        if ( empty( $plain_lines ) ) {
            return array( '', '' );
        }

        $plain = implode( "\n", array_map( 'trim', $plain_lines ) );
        $html  = $html_items ? '<ul style="margin:0;padding-left:18px;">' . implode( '', $html_items ) . '</ul>' : '';

        return array( $plain, $html );
    }

    /**
     * Normalise repeater rows into plain text and HTML table output.
     *
     * @param array  $rows       Repeater rows.
     * @param string $empty_text Placeholder text.
     * @param string $empty_html Placeholder HTML.
     * @return array{string,string}
     */
    protected function normalise_repeater_output( array $rows, $empty_text, $empty_html, $path = '' ) {
        $columns = array();
        foreach ( $rows as $row ) {
            foreach ( $row as $col_key => $_ ) {
                if ( $this->is_tel_helper_key( $col_key ) ) {
                    continue;
                }
                $columns[ $col_key ] = true;
            }
        }
        $columns = array_keys( $columns );

        if ( empty( $columns ) ) {
            return $this->normalise_list_output( $rows, $empty_text, $empty_html, $path );
        }

        $plain_rows = array();
        $html_rows  = array();

        foreach ( $rows as $index => $row ) {
            $pairs      = array();
            $cell_htmls = array();

            foreach ( $columns as $column ) {
                $cell_value = array_key_exists( $column, $row ) ? $row[ $column ] : '';
                $cell_path  = $path !== '' ? $path . '|' . $index . '|' . $column : $column;
                list( $cell_plain, $cell_html ) = $this->normalise_field_output( $cell_value, $cell_path );
                if ( '' === $cell_plain ) {
                    $cell_plain = $empty_text;
                }
                if ( '' === $cell_html ) {
                    $cell_html = $empty_html;
                }
                $cell_label = $this->is_label_key_mode() ? $this->lookup_label_for_path( $cell_path, (string) $column ) : (string) $column;
                $pairs[]      = $cell_label . ': ' . $cell_plain;
                $cell_htmls[] = '<td style="padding:8px 12px;border:1px solid #e2e8f0;font-size:13px;line-height:1.5;">' . $cell_html . '</td>';
            }

            $plain_rows[] = sprintf(
                '#%1$d %2$s',
                $index + 1,
                $pairs ? implode( '; ', $pairs ) : $empty_text
            );
            $html_rows[] = '<tr>' . implode( '', $cell_htmls ) . '</tr>';
        }

        $head_cells = array();
        foreach ( $columns as $column ) {
            $header_path = $path !== '' ? $path . '|' . $column : $column;
            $header_label = $this->is_label_key_mode() ? $this->lookup_label_for_path( $header_path, (string) $column ) : (string) $column;
            $head_cells[] = '<th scope="col" style="text-align:left;padding:8px 12px;border:1px solid #e2e8f0;background:#f8fafc;font-size:12px;font-weight:600;">' . esc_html( $header_label ) . '</th>';
        }

        $html_table = '<div class="stacklar-email-template-repeater" style="margin:6px 0;">'
            . '<table style="width:100%;border-collapse:collapse;border:1px solid #e2e8f0;">'
            . '<thead><tr>' . implode( '', $head_cells ) . '</tr></thead>'
            . '<tbody>' . implode( '', $html_rows ) . '</tbody>'
            . '</table>'
            . '</div>';

        $plain = implode( "\n", array_map( 'trim', $plain_rows ) );

        return array( $plain, $html_table );
    }

    /**
     * Resolve the base key and helper type for telephone helper inputs.
     *
     * @param mixed $key
     * @return array{0:?string,1:?string}
     */
    protected function detect_tel_helper_key( $key ) {
        if ( ! is_scalar( $key ) ) {
            return array( null, null );
        }

        $normalized = sanitize_key( (string) $key );
        if ( '' === $normalized ) {
            return array( null, null );
        }

        if ( substr( $normalized, -13 ) === '_intl_display' ) {
            return array( substr( $normalized, 0, -13 ), 'intl_display' );
        }

        if ( substr( $normalized, -9 ) === '_national' ) {
            return array( substr( $normalized, 0, -9 ), 'national' );
        }

        if ( substr( $normalized, -8 ) === '_country' ) {
            return array( substr( $normalized, 0, -8 ), 'country' );
        }

        return array( null, null );
    }

    /**
     * Check whether a key represents a helper field for telephone inputs.
     *
     * @param mixed $key
     * @return bool
     */
    protected function is_tel_helper_key( $key ) {
        list( $base, $type ) = $this->detect_tel_helper_key( $key );
        return ( null !== $base && null !== $type );
    }

    /**
     * Determine whether a value should be treated as empty for output purposes.
     *
     * @param mixed $value
     * @return bool
     */
    protected function is_empty_field_value( $value ) {
        if ( is_array( $value ) ) {
            foreach ( $value as $item ) {
                if ( ! $this->is_empty_field_value( $item ) ) {
                    return false;
                }
            }
            return true;
        }

        if ( null === $value || $value === false ) {
            return true;
        }

        if ( is_string( $value ) ) {
            return trim( $value ) === '';
        }

        return $value === '';
    }

    /**
     * Merge telephone helper values back into their base field when missing.
     *
     * @param mixed $value
     * @return mixed
     */
    protected function merge_tel_helpers( $value ) {
        if ( ! is_array( $value ) ) {
            return $value;
        }

        $merged = array();
        foreach ( $value as $key => $child ) {
            $merged[ $key ] = $this->merge_tel_helpers( $child );
        }

        if ( ! wp_is_numeric_array( $merged ) ) {
            foreach ( $merged as $key => $child ) {
                list( $base, $type ) = $this->detect_tel_helper_key( $key );
                if ( null === $base || null === $type ) {
                    continue;
                }
                if ( 'intl_display' !== $type && 'national' !== $type ) {
                    continue;
                }
                if ( $this->is_empty_field_value( $child ) ) {
                    continue;
                }
                if ( isset( $merged[ $base ] ) && ! $this->is_empty_field_value( $merged[ $base ] ) ) {
                    continue;
                }
                $merged[ $base ] = $child;
            }
        }

        return $merged;
    }

    /**
     * Determine whether every list item is an associative array.
     *
     * @param array $items List items.
     * @return bool
     */
    protected function all_items_are_assoc( array $items ) {
        if ( empty( $items ) ) {
            return false;
        }
        foreach ( $items as $item ) {
            if ( ! is_array( $item ) || wp_is_numeric_array( $item ) ) {
                return false;
            }
        }
        return true;
    }
}