/*
 * Copyright (C) 2022 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

importScripts('sql-wasm.js', "TempSql.js");
let conn: any = null;
let encoder = new TextEncoder();
function initIndexedDB() {
    return new Promise((resolve, reject) => {
        let request = indexedDB.open("systrace");
        request.onerror = function (event) {
        };
        request.onsuccess = function (event) {
            let db = request.result;
            resolve(db);
        };
        request.onupgradeneeded = function (event) {
            // @ts-ignore
            let db = event!.target!.result;
            if (!db.objectStoreNames.contains("connection")) {
                db.createObjectStore("connection", {autoIncrement: true});
            }
        };
    })
}

function readConnection(store: IDBObjectStore) {
    return new Promise((resolve, reject) => {
        let request = store.get(1);
        request.onsuccess = function (event) {
            // @ts-ignore
            resolve(event.target.result);
        };
        request.onerror = function (event) {
            // @ts-ignore
            reject(event.target.result);
        };
    })
}

function deleteConnection(store: IDBObjectStore, id: number) {
    return new Promise((resolve, reject) => {
        let request = store.delete(id);
        request.onsuccess = function (event) {
            // @ts-ignore
            resolve(event.target.result);
        };
        request.onerror = function (event) {
            // @ts-ignore
            reject(event.target.result);
        };
    })
}

let mergedUnitArray = (bufferSlice:Array<Uint8Array>)=>{
    let length = 0;
    bufferSlice.forEach(item => {
        length += item.length;
    });
    let mergedArray = new Uint8Array(length);
    let offset = 0;
    bufferSlice.forEach(item => {
        mergedArray.set(item, offset);
        offset += item.length;
    });
    return mergedArray;
}

self.onerror = function (error) {
}


self.onmessage = async (e: any) => {
    if (e.data.action === "open") {
        let array = new Uint8Array(e.data.buffer);
        // @ts-ignore
        initSqlJs({locateFile: filename => `${filename}`}).then((SQL: any) => {
            conn = new SQL.Database(array);
            // @ts-ignore
            self.postMessage({id: e.data.id, ready: true, index: 0});
            temp_init_sql_list.forEach((item, index) => {
                let r = conn.exec(item);
                // @ts-ignore
                self.postMessage({id: e.data.id, ready: true, index: index + 1});
            });
            // @ts-ignore
            self.postMessage({id: e.data.id, init: true});
        });
    } else if (e.data.action === "close") {
    } else if (e.data.action === "exec"||e.data.action === "exec-buf") {
        try {
            let action = e.data.action; //: "exec"
            let sql = e.data.sql;
            let params = e.data.params;
            const stmt = conn.prepare(sql);
            stmt.bind(params);
            let res = [];
            while (stmt.step()) { //
                res.push(stmt.getAsObject());
            }
            stmt.free();
            // @ts-ignore
            self.postMessage({id: e.data.id, results: res});
        } catch (err: any) {
            // @ts-ignore
            self.postMessage({id: e.data.id, results: [], error: err.message});
        }
    }
}