// export const ts = (window as any).ts;
// import * as typescriptlib from '!!raw-loader!../../../node_modules/typescript/lib/lib.d.ts'
// import * as typescriptes5 from '!!raw-loader!../../../node_modules/typescript/lib/lib.es5.d.ts'
import typescriptlib from 'type_decls.d';
import * as ts from 'typescript';
import { Doc, FieldType } from '../../fields/Doc';
import { RefField } from '../../fields/RefField';
import { ScriptField } from '../../fields/ScriptField';
import { ScriptingGlobals, scriptingGlobals } from './ScriptingGlobals';

export { ts };

export interface ScriptSuccess {
    success: true;
    result: unknown;
}

export interface ScriptError {
    success: false;
    error: unknown;
    result: unknown;
}

export type ScriptResult = ScriptSuccess | ScriptError;

export type ScriptParam = { [name: string]: string };

export interface CompiledScript {
    readonly compiled: true;
    readonly originalScript: string;
    // eslint-disable-next-line no-use-before-define
    readonly options: Readonly<ScriptOptions>;
    run(args?: { [name: string]: unknown }, onError?: (res: string) => void, errorVal?: unknown): ScriptResult;
}

export interface CompileError {
    compiled: false;
    errors: ts.Diagnostic[];
}

export type CompileResult = CompiledScript | CompileError;
export function isCompileError(toBeDetermined: CompileResult): toBeDetermined is CompileError {
    if ((toBeDetermined as CompileError).errors) {
        return true;
    }
    return false;
}

// eslint-disable-next-line no-use-before-define
function Run(script: string | undefined, customParams: string[], diagnostics: ts.Diagnostic[], originalScript: string, options: ScriptOptions): CompileResult {
    const errors = diagnostics.filter(diag => diag.category === ts.DiagnosticCategory.Error).filter(diag => diag.code !== 2304 && diag.code !== 2339);
    if ((options.typecheck !== false && errors.length) || !script) {
        return { compiled: false, errors };
    }

    const paramNames = Object.keys(scriptingGlobals);
    const params = paramNames.map(key => scriptingGlobals[key]);
    // let fieldTypes = [Doc, ImageField, PdfField, VideoField, AudioField, List, RichTextField, ScriptField, ComputedField, CompileScript];
    // let paramNames = ["Docs", ...fieldTypes.map(fn => fn.name)];
    // let params: any[] = [Docs, ...fieldTypes];
    const compiledFunction = (() => {
        try {
            return new Function(...paramNames, `return ${script}`);
        } catch (e) {
            console.log(e);
            return undefined;
        }
    })();
    if (!compiledFunction) return { compiled: false, errors };
    const { capturedVariables = {} } = options;
    const run = (args: { [name: string]: unknown } = {}, onError?: (e: string) => void, errorVal?: ts.Diagnostic): ScriptResult => {
        const argsArray: unknown[] = [];
        for (const name of customParams) {
            if (name !== 'this') {
                argsArray.push(name in args ? args[name] : capturedVariables[name]);
            }
        }
        const thisParam = args.this || capturedVariables.this;
        let batch: { end(): void } | undefined;
        try {
            if (!options.editable) {
                batch = Doc.MakeReadOnly();
            }

            const result = compiledFunction.apply(thisParam, params).apply(thisParam, argsArray);
            batch?.end();
            return { success: true, result };
        } catch (error) {
            batch?.end();
            onError?.(script + ' ' + (error as string).toString());
            return { success: false, error, result: errorVal };
        }
    };
    return { compiled: true, run, originalScript, options };
}

interface File {
    fileName: string;
    content: string;
}

// class ScriptingCompilerHost implements ts.CompilerHost {
class ScriptingCompilerHost {
    files: File[] = [];

    // getSourceFile(fileName: string, languageVersion: ts.ScriptTarget, onError?: ((message: string) => void) | undefined, shouldCreateNewSourceFile?: boolean | undefined): ts.SourceFile | undefined {
    getSourceFile(fileName: string, languageVersion: ts.ScriptTarget | ts.CreateSourceFileOptions /* , onError?: ((message: string) => void) | undefined, shouldCreateNewSourceFile?: boolean | undefined */): ts.SourceFile | undefined {
        const contents = this.readFile(fileName);
        if (contents !== undefined) {
            return ts.createSourceFile(fileName, contents, languageVersion, true);
        }
        return undefined;
    }

    // getDefaultLibFileName(options: ts.CompilerOptions): string {
    getDefaultLibFileName(/* options: any */): string {
        return 'node_modules/typescript/lib/lib.d.ts'; // No idea what this means...
    }
    writeFile(fileName: string, content: string) {
        const file = this.files.find(f => f.fileName === fileName);
        if (file) {
            file.content = content;
        } else {
            this.files.push({ fileName, content });
        }
    }
    getCurrentDirectory(): string {
        return '';
    }
    getCanonicalFileName(fileName: string): string {
        return this.useCaseSensitiveFileNames() ? fileName : fileName.toLowerCase();
    }
    useCaseSensitiveFileNames(): boolean {
        return true;
    }
    getNewLine(): string {
        return '\n';
    }
    fileExists(fileName: string): boolean {
        return this.files.some(file => file.fileName === fileName);
    }
    readFile(fileName: string): string | undefined {
        const file = this.files.find(f => f.fileName === fileName);
        if (file) {
            return file.content;
        }
        return undefined;
    }
}

export type Traverser = (node: ts.Node, indentation: string) => boolean | void;
export type TraverserParam = Traverser | { onEnter: Traverser; onLeave: Traverser };
export type Transformer = {
    transformer: ts.TransformerFactory<ts.Node>;
    getVars?: () => { [name: string]: FieldType };
};
export interface ScriptOptions {
    requiredType?: string; // does function required a typed return value
    addReturn?: boolean; // does the compiler automatically add a return statement
    params?: { [name: string]: string }; // list of function parameters and their types
    capturedVariables?: { [name: string]: Doc | number | string | boolean | undefined }; // list of captured variables
    typecheck?: boolean; // should the compiler perform typechecking
    editable?: boolean; // can the script edit Docs
    traverser?: TraverserParam;
    transformer?: Transformer; // does the editor display a text label by each document that can be used as a captured document reference
    globals?: { [name: string]: unknown };
}

// function forEachNode(node:ts.Node, fn:(node:any) => void);
function forEachNode(node: ts.Node, onEnter: Traverser, onExit?: Traverser, indentation = '') {
    return (
        onEnter(node, indentation) ||
        // eslint-disable-next-line @typescript-eslint/no-explicit-any
        ts.forEachChild(node, (n: any) => {
            forEachNode(n, onEnter, onExit, indentation + '    ');
        }) ||
        (onExit && onExit(node, indentation))
    );
}

export function CompileScript(script: string, options: ScriptOptions = {}): CompileResult {
    const captured = options.capturedVariables ?? {};
    const signature = Object.keys(captured).reduce((p, v) => {
        const formatCapture = (obj: FieldType | undefined) => `${v}=${obj instanceof RefField ? 'XXX' : obj?.toString()}`;
        const captureVal = captured[v];
        if (captureVal instanceof Array) return p + captureVal.map(formatCapture);
        return p + formatCapture(captured[v]);
    }, '');
    const found = ScriptField.GetScriptFieldCache(script + ':' + signature); // if already compiled, found is the result; cache set below
    if (found) return found as CompiledScript;
    options.typecheck = true;
    const { requiredType = '', addReturn = false, params = {}, capturedVariables = {}, typecheck = true } = options;
    if (options.params && !options.params.this) options.params.this = Doc.name;
    if (options.globals) {
        ScriptingGlobals.setScriptingGlobals(options.globals);
    }
    const host = new ScriptingCompilerHost();
    if (options.traverser) {
        const sourceFile = ts.createSourceFile('script.ts', script, ts.ScriptTarget.ES2015, true);
        const onEnter = typeof options.traverser === 'object' ? options.traverser.onEnter : options.traverser;
        const onLeave = typeof options.traverser === 'object' ? options.traverser.onLeave : undefined;
        forEachNode(sourceFile, onEnter, onLeave);
    }
    if (options.transformer) {
        const sourceFile = ts.createSourceFile('script.ts', script, ts.ScriptTarget.ES2015, true);
        const result = ts.transform(sourceFile, [options.transformer.transformer]);
        const newCaptures = options.transformer.getVars?.();
        if (Object.keys(newCaptures ?? {}).length) {
            // tslint:disable-next-line: prefer-object-spread
            // options.capturedVariables = Object.assign(capturedVariables, newCaptures!) as any;

            const { transformed } = result;
            const printer = ts.createPrinter({
                newLine: ts.NewLineKind.LineFeed,
            });
            // eslint-disable-next-line no-param-reassign
            script = printer.printFile(transformed[0].getSourceFile());
        }
        result.dispose();
    }
    const paramNames: string[] = [];
    if ('this' in params || 'this' in capturedVariables) {
        paramNames.push('this');
    }
    paramNames.push(...Object.keys(params).filter(p => p!== 'this' && !Object.keys(capturedVariables).includes(p)));

    const paramList = paramNames.map(key => {
        const val = typeof params[key] === "string" && params[key].length && !"\"'`".includes(params[key][0]) ? `"${params[key]}"` : params[key];
        return `${key}: ${val}`;
    });
    for (const key in capturedVariables) {
        if (key !== 'this') {
            const val = capturedVariables[key];
            paramNames.push(key);
            paramList.push(`${key}: ${typeof val === 'object' ? Object.getPrototypeOf(val).constructor.name : typeof val}`);
        }
    }
    const paramString = paramList.join(', ');
    const body = addReturn && !script.startsWith('{ return') ? `return ${script};` : script;
    const reqTypes = requiredType ? `: ${requiredType}` : '';
    const funcScript = `(function(${paramString})${reqTypes} { ${body} })`;
    host.writeFile('file.ts', funcScript);

    if (typecheck) host.writeFile('node_modules/typescript/lib/lib.d.ts', typescriptlib);
    const program = ts.createProgram(['file.ts'], {}, host);
    const testResult = program.emit();
    const outputText = host.readFile('file.js');

    const diagnostics = ts.getPreEmitDiagnostics(program).concat(testResult.diagnostics);
    if (script.startsWith('@')) options.typecheck = true; // need the compilation to fail so that the script will return itself as a string (instead of nothing)
    const result = Run(outputText, paramNames, diagnostics, script, options);

    if (options.globals) {
        ScriptingGlobals.resetScriptingGlobals();
    }
    !signature.includes('XXX') && ScriptField._scriptFieldCache.set(script + ':' + signature, result as CompiledScript);
    return result;
}