<?php

class Meow_MWAI_Modules_Discussions {
  private $wpdb = null;
  private $core = null;
  private $table_chats = null;
  private $db_check = false;
  private $namespace_admin = 'mwai/v1';
  private $namespace_ui = 'mwai-ui/v1';

  public function __construct() {
    global $wpdb;
    global $mwai_core;
    $this->core = $mwai_core;
    $this->wpdb = $wpdb;
    $this->table_chats = $wpdb->prefix . 'mwai_chats';

    if ( $this->core->get_option( 'shortcode_chat_discussions' ) ) {
      add_filter( 'mwai_chatbot_reply', [ $this, 'chatbot_reply' ], 10, 4 );
      add_action( 'rest_api_init', [ $this, 'rest_api_init' ] );
    }
  }

  public function rest_api_init() {

    // Admin
		register_rest_route( $this->namespace_admin, '/discussions/list', [
			'methods' => 'POST',
			'callback' => [ $this, 'rest_discussions_list' ],
			'permission_callback' => [ $this->core, 'can_access_settings' ],
		] );
    register_rest_route( $this->namespace_admin, '/discussions/delete', [
      'methods' => 'POST',
      'callback' => [ $this, 'rest_discussions_delete' ],
      'permission_callback' => [ $this->core, 'can_access_settings' ],
    ] );

    // UI
    register_rest_route( $this->namespace_ui, '/discussions/list', [
			'methods' => 'POST',
			'callback' => [ $this, 'rest_discussions_ui_list' ],
			'permission_callback' => '__return_true'
		] );
	}

  function rest_discussions_list( $request ) {
		try {
			$params = $request->get_json_params();
			$offset = $params['offset'];
			$limit = $params['limit'];
      $filters = $params['filters'];
			$sort = $params['sort'];
			$chats = $this->chats_query( [], $offset, $limit, $filters, $sort );
			return new WP_REST_Response([ 'success' => true, 'total' => $chats['total'], 'chats' => $chats['rows'] ], 200 );
		}
		catch ( Exception $e ) {
			return new WP_REST_Response([ 'success' => false, 'message' => $e->getMessage() ], 500 );
		}
	}

  function rest_discussions_ui_list( $request ) {
		try {
			$params = $request->get_json_params();
			$offset = isset( $params['offset'] ) ? $params['offset'] : 0;
			$limit = isset( $params['limit'] ) ? $params['limit'] : 10;
      $botId = isset( $params['botId'] ) ? $params['botId'] : null;

      if ( is_null( $botId ) ) {
        return new WP_REST_Response([ 'success' => false, 'message' => "Bot ID is required." ], 200 );
      }

      $userId = get_current_user_id();
      if ( !$userId ) {
        return new WP_REST_Response([ 'success' => false, 'message' => "You need to be connected." ], 200 );
      }
			$filters = [ 
        [ 'accessor' => 'user', 'value' => $userId ],
        [ 'accessor' => 'botId', 'value' => $botId ],
      ];
			$chats = $this->chats_query( [], $offset, $limit, $filters );
			return new WP_REST_Response([ 'success' => true, 'total' => $chats['total'], 'chats' => $chats['rows'] ], 200 );
		}
		catch ( Exception $e ) {
			return new WP_REST_Response([ 'success' => false, 'message' => $e->getMessage() ], 500 );
		}
	}

  function rest_discussions_delete( $request ) {
    try {
      $params = $request->get_json_params();
      $chatsIds = $params['chatIds'];
      if ( is_array( $chatsIds ) ) {
        if ( count( $chatsIds ) === 0 ) {
          $this->wpdb->query( "TRUNCATE TABLE $this->table_chats" );
        }
        foreach( $chatsIds as $chatId ) {
          $this->wpdb->delete( $this->table_chats, [ 'chatId' => $chatId ] );
        }
      }
      return new WP_REST_Response([ 'success' => true ], 200 );
    }
    catch ( Exception $e ) {
      return new WP_REST_Response([ 'success' => false, 'message' => $e->getMessage() ], 500 );
    }
  }
  
  // Get latest discussion for the given parameter
  function get_discussion( $botId, $chatId ) {
    $this->check_db();
    $chat = $this->wpdb->get_row( $this->wpdb->prepare( "SELECT *
      FROM $this->table_chats
      WHERE chatId = %s AND botId = %s", $chatId, $botId
    ) );
    if ( $chat ) {
      $chat->messages = json_decode( $chat->messages );
      return $chat;
    }
    return null;
  }

  function chats_query( $chats = [], $offset = 0, $limit = null, $filters = null, $sort = null ) {
    $this->check_db();
    $offset = !empty( $offset ) ? intval( $offset ) : 0;
    $limit = !empty( $limit ) ? intval( $limit ) : 5;
    $filters = !empty( $filters ) ? $filters : [];
    $sort = !empty( $sort ) ? $sort : [ 'accessor' => 'updated', 'by' => 'desc' ];
    $query = "SELECT * FROM $this->table_chats";

    // Filters
    if ( is_array( $filters ) ) {
      $where = array();
      foreach ( $filters as $filter ) {
        if ( $filter['accessor'] === 'user' ) {
          $value = esc_sql( $filter['value'] );
          if ( is_null( $value ) || $value === '' ) {
            continue;
          }
          $isIP = filter_var( $value, FILTER_VALIDATE_IP );
          if ( $isIP ) {
            $where[] = "ip = '{$value}'";
          }
          else {
            $where[] = "userId = '{$value}'";
          }
        }
        if ( $filter['accessor'] === 'botId' ) {
          $value = esc_sql( $filter['value'] );
          if ( is_null( $value ) || $value === '' ) {
            continue;
          }
          $where[] = "botId = '{$value}'";
        }
        if ( $filter['accessor'] === 'preview' ) {
          $value = $filter['value'];
          if ( empty( $value ) ) {
            continue;
          }
          $where[] = "messages LIKE '%{$value}%'";
        }
      }
      if ( count( $where ) > 0 ) {
        $query .= " WHERE " . implode( " AND ", $where );
      }
    }

    // Count based on this query
    $chats['total'] = $this->wpdb->get_var( "SELECT COUNT(*) FROM ($query) AS t" );

    // Order by
    $query .= " ORDER BY " . esc_sql( $sort['accessor'] ) . " " . esc_sql( $sort['by'] );

    // Limits
    if ( $limit > 0 ) {
      $query .= " LIMIT $offset, $limit";
    }

    $chats['rows'] = $this->wpdb->get_results( $query, ARRAY_A );
    return $chats;
  }

  function chatbot_reply( $rawText, $query, $params, $extra ) {
    global $mwai_core;
    $userIp = $mwai_core->get_ip_address();
    $userId = $mwai_core->get_user_id();
    $botId = isset( $params['botId'] ) ? $params['botId'] : null;
    $chatId = isset( $params['chatId'] ) ? $params['chatId'] : $query->session;
    $newMessage = isset( $params['newMessage'] ) ? $params['newMessage'] : $query->prompt;
    //$chatId = hash( 'sha256', $userIp . $userId . $clientChatId );
    $this->check_db();
    $chat = $this->wpdb->get_row( $this->wpdb->prepare( "SELECT * FROM $this->table_chats WHERE chatId = %s", $chatId ) );
    $extra = [
      'embeddings' => isset( $extra['embeddings'] ) ? $extra['embeddings'] : null
    ];
    if ( $chat ) {
      $chat->messages = json_decode( $chat->messages );
      $chat->messages[] = [
        'role' => 'user',
        'content' => $newMessage
      ];
      $chat->messages[] = [
        'role' => 'assistant',
        'content' => $rawText,
        'extra' => $extra
      ];
      $chat->messages = json_encode( $chat->messages );
      $this->wpdb->update( $this->table_chats, [ 
        'userId' => $userId,
        'messages' => $chat->messages,
        'updated' => date( 'Y-m-d H:i:s' )
       ], [ 'id' => $chat->id ] );
    }
    else {
      $chat = [
        'userId' => $userId,
        'ip' => $userIp,
        'messages' => json_encode( [
          [
            'role' => 'user',
            'content' => $newMessage
          ],
          [
            'role' => 'assistant',
            'content' => $rawText,
            'extra' => $extra
          ]
        ] ),
        'extra' => json_encode( [
          'session' => $query->session,
          'model' => $query->model,
          'temperature' => $query->temperature,
          'context' => $query->context,
        ] ),
        'botId' => $botId,
        'chatId' => $chatId,
        'created' => date( 'Y-m-d H:i:s' ),
        'updated' => date( 'Y-m-d H:i:s' )
      ];
      $this->wpdb->insert( $this->table_chats, $chat );
    }
    return $rawText;
  }

  function check_db() {
    if ( $this->db_check ) {
      return true;
    }
    $this->db_check = !( strtolower( 
      $this->wpdb->get_var( "SHOW TABLES LIKE '$this->table_chats'" ) ) != strtolower( $this->table_chats )
    );
    if ( !$this->db_check ) {
      $this->create_db();
      $this->db_check = !( strtolower( 
        $this->wpdb->get_var( "SHOW TABLES LIKE '$this->table_chats'" ) ) != strtolower( $this->table_chats )
      );
    }

    // LATER: REMOVE THIS AFTER SEPTEMBER 2023
    // Make sure the column "userId" and "ip "exist in the $this->table_chats table
    $this->db_check = $this->db_check && $this->wpdb->get_var( "SHOW COLUMNS FROM $this->table_chats LIKE 'userId'" );
    if ( !$this->db_check ) {
      $this->wpdb->query( "ALTER TABLE $this->table_chats ADD COLUMN userId BIGINT(20) NULL" );
      $this->wpdb->query( "ALTER TABLE $this->table_chats ADD COLUMN ip VARCHAR(64) NULL" );
      $this->wpdb->query( "ALTER TABLE $this->table_chats ADD COLUMN botId VARCHAR(64) NULL" );
      $this->db_check = true;
    }

    return $this->db_check;
  }

  function create_db() {
    $charset_collate = $this->wpdb->get_charset_collate();
    $sqlLogs = "CREATE TABLE $this->table_chats (
      id BIGINT(20) NOT NULL AUTO_INCREMENT,
      userId BIGINT(20) NULL,
      ip VARCHAR(64) NULL,
      messages TEXT NOT NULL NULL,
      extra TEXT NOT NULL NULL,
      botId VARCHAR(64) NULL,
      chatId VARCHAR(64) NOT NULL,
      created DATETIME NOT NULL,
      updated DATETIME NOT NULL,
      PRIMARY KEY  (id),
      INDEX chatId (chatId)
    ) $charset_collate;";
    require_once( ABSPATH . 'wp-admin/includes/upgrade.php' );
    dbDelta( $sqlLogs );
  }

}