import * as ts from "typescript";
const fs = require('fs');
import * as assert from 'assert'

const TMP_FILENAME = "tmp.ts";

function diagnosticMsgToString(diagMsg: string|ts.DiagnosticMessageChain): string {
    if (typeof diagMsg === "string") {
        return diagMsg;
    }
    let curMsg: ts.DiagnosticMessageChain|undefined = diagMsg;
    while (curMsg) {
        if (typeof curMsg.messageText === "string") {
            return curMsg.messageText;
        }
        curMsg = curMsg.next;
    }
    return "found no error";
}

function diagnosticMsgContains(diagMsg: string|ts.DiagnosticMessageChain, contents: string): boolean {
    return diagnosticMsgToString(diagMsg).indexOf(contents) >= 0;
}

/**
 * @hidden
 */
export function assertFailCompile(contents: string, expectedMsg: string): void {
    fs.writeFileSync(
        TMP_FILENAME, "import { HashSet } from './dist/src/HashSet';" +
            " import { Stream } from './dist/src/Stream';" +
            " import { LinkedList } from './dist/src/LinkedList';" +
            " import { HashMap } from './dist/src/HashMap';" +
            " import { Option } from './dist/src/Option';" +
            " import { Either } from './dist/src/Either';" +
            " import { Vector } from './dist/src/Vector';" + contents);
    const tsProgram = ts.createProgram([TMP_FILENAME], {target:ts.ScriptTarget.ES2016});
    const emitResult = tsProgram.emit();
    const allDiagnostics = ts.getPreEmitDiagnostics(tsProgram)
        .concat(emitResult.diagnostics as ts.Diagnostic[]);
    const allErrorsTxt = allDiagnostics.map(x => diagnosticMsgToString(x.messageText)).join(", ");
    // for some reason getting tons of 'cannot find module' errors
    // on circleCI. The test is otherwise still valid since i do "contains"
    // and the real error is still in there.
    //
    // if (allDiagnostics.length > 1) {
    //     console.log(allErrorsTxt);
    // }
    // assert.equal(1, allDiagnostics.length);
    const isMatch = allDiagnostics.filter(d => diagnosticMsgContains(d.messageText, expectedMsg)).length > 0;
    if (isMatch) {
        assert.ok(true);
    } else {
        assert.equal(allErrorsTxt, expectedMsg);
    }
    fs.unlinkSync(TMP_FILENAME);
    fs.unlinkSync(TMP_FILENAME.replace(/.ts$/, ".js"));
}