const fs = require("fs");
const sql = require("mssql/msnodesqlv8");

const defaultCaseSpecs = {
    clientId: 9053,
    caseName: "toothache"
};

class Request {

    constructor(config) {
        this.config = Object.assign({}, config);
    }

    async newCase(caseSpecs) {
        let connection = await this.$connect();
        let caseP = await this.$enchanceCase(caseSpecs, connection);
        let queryResult = await connection.request().query(this.$withMetadata(`
DECLARE @NewID INT
EXEC pr_Case_INSERT @MetaData, '${case.clientId}', '', '${case.caseName}', NULL, @NewID OUTPUT
SELECT @NewID AS NewCaseID
        `));
        await connection.request().query(this.$withMetadata(`
EXEC pr_CasesForClient_SELECT @MetaData, ${case.clientId}
EXEC pr_CaseStatusForClient_SELECT @MetaData, ${case.clientId}
        `));
        caseP.patientId = patientId;
        return caseP;
    }

    async cleanup() {
        this.pool && this.pool.close();
    }

    async $connect() {
        if (!this.pool) {
            this.pool = new sql.ConnectionPool(this.config);
            await this.pool.connect();
        }
        return this.pool;
    }

    $withMetadata(sql) {
        return `
DECLARE @MetaData TT_MetaData
INSERT INTO @MetaData (TenantID, UserID, TimeZoneOffset, UseDaylightSavingsTime) VALUES (${this.config.tenantId}, ${this.config.userId}, -6, 1)
        ` + sql;
    }

    async $enchanceCase(caseSpecs, connection) {
        caseSpecs = Object.assign({}, defaultCaseSpecs, caseSpecs);
        //if (!caseSpecs.caseName) {
        //    caseSpecs.caseName = `Test-${new Date().getTime()}-${Math.floor(Math.random() * 100)}`;
        //}
        return caseSpecs;
    }
}

function readConfig(fileName) {
    try {
        return JSON.parse(fs.readFileSync(fileName, "utf8"));
    }
    catch (error) {
        if (error.code !== "ENOENT") {
            throw error;
        }
        return undefined;
    }
}

function mergeConfigs(...configs) {
    let merged = {};
    for (let config of configs) {
        if (!config) continue;
        let options = merged.options;
        Object.assign(merged, config);
        if (options || config.options) {
            merged.options = Object.assign({}, options, config.options);
        }
    }
    return merged;
}

const defaultConfig = {
    server: ".",
    database: "clntacl",
    options: {
        trustedConnection: true
    }
};

const config = mergeConfigs(defaultConfig,
    readConfig("./database.json"), readConfig("./database.local.json"));

const request = new Request(config);

module.exports = request;