import * as SQLite from 'expo-sqlite';
const db = SQLite.openDatabase('lnreader.db');

const getLibraryQuery = (sort, filter) => `
    SELECT novels.*, C.chaptersUnread, D.chaptersDownloaded, H.lastReadAt
    FROM novels
    LEFT JOIN (
        SELECT chapters.novelId, COUNT(*) AS chaptersUnread 
        FROM chapters
        WHERE chapters.read = 0
        GROUP BY chapters.novelId
    ) AS C
    ON novels.novelId = C.novelId
    LEFT JOIN (
        SELECT chapters.novelId, COUNT(*) AS chaptersDownloaded 
        FROM chapters
        WHERE chapters.downloaded = 1
        GROUP BY chapters.novelId
    ) AS D
    ON novels.novelId = D.novelId
    LEFT JOIN (
        SELECT history.historyNovelId as novelId, historyTimeRead AS lastReadAt
        FROM history
        GROUP BY history.historyNovelId
        HAVING history.historyTimeRead = MAX(history.historyTimeRead)
        ORDER BY history.historyTimeRead DESC
    ) AS H
    ON novels.novelId = H.novelId
    WHERE novels.followed = 1 ${filter ? 'AND ' + filter : ''}
    ${sort ? 'ORDER BY ' + sort : ''}
    `;

export const getLibrary = (sort, filter) => {
  return new Promise((resolve, reject) =>
    db.transaction(tx => {
      tx.executeSql(
        getLibraryQuery(sort, filter),
        null,
        (txObj, { rows: { _array } }) => {
          // console.log(JSON.stringify(_array, null, 2));
          resolve(_array);
        },
        (txObj, error) => {
          // console.log('Error ', error);
        },
      );
    }),
  );
};

const searchLibraryQuery = (searchText, sort, filter) =>
  `
    SELECT novels.*, C.chaptersUnread, D.chaptersDownloaded, H.lastReadAt
    FROM novels
    LEFT JOIN (
        SELECT chapters.novelId, COUNT(*) AS chaptersUnread 
        FROM chapters
        WHERE chapters.read = 0
        GROUP BY chapters.novelId
    ) AS C
    ON novels.novelId = C.novelId
    LEFT JOIN (
        SELECT chapters.novelId, COUNT(*) AS chaptersDownloaded 
        FROM chapters
        WHERE chapters.downloaded = 1
        GROUP BY chapters.novelId
    ) AS D
    ON novels.novelId = D.novelId
    LEFT JOIN (
        SELECT history.historyNovelId as novelId, historyTimeRead AS lastReadAt
        FROM history
        GROUP BY history.historyNovelId
        HAVING history.historyTimeRead = MAX(history.historyTimeRead)
        ORDER BY history.historyTimeRead DESC
    ) AS H
    ON novels.novelId = H.novelId
    WHERE novels.followed = 1 AND novelName LIKE '%${searchText}%'  ${
    filter ? 'AND ' + filter : ''
  }
    ${sort ? 'ORDER BY ' + sort : ''} `;

export const searchLibrary = (searchText, sort, filter) => {
  return new Promise((resolve, reject) => {
    db.transaction(tx => {
      tx.executeSql(
        searchLibraryQuery(searchText, sort, filter),
        null,
        (txObj, { rows: { _array } }) => resolve(_array),
        (txObj, error) => {
          // console.log('Error ', error);
        },
      );
    });
  });
};