export type TSmartcliTerminalTaskStatus = 'running' | 'completed' | 'failed';

export interface ISmartcliWritable {
  isTTY?: boolean;
  columns?: number;
  write(chunk: string): void | boolean;
}

export interface ISmartcliTerminalOptions {
  stream?: ISmartcliWritable;
  interactive?: boolean;
  colors?: boolean;
}

export interface ISmartcliTerminalTaskOptions {
  job: string;
  rows?: number;
  logLimit?: number;
}

export interface ISmartcliTerminalAttachErrorOptions {
  keepOpen?: boolean;
}

const ansiCodes = {
  reset: '\u001B[0m',
  red: '\u001B[31m',
  green: '\u001B[32m',
  cyan: '\u001B[36m',
  gray: '\u001B[90m',
};

/**
 * A live terminal renderer for multiple fixed-row tasks.
 * It automatically falls back to append-only logs in non-interactive environments.
 */
export class SmartcliTerminal {
  private stream: ISmartcliWritable;
  private interactive: boolean;
  private colors: boolean;
  private tasks: SmartcliTerminalTask[] = [];
  private renderedLineCount = 0;

  constructor(optionsArg: ISmartcliTerminalOptions = {}) {
    this.stream = optionsArg.stream || getDefaultStream();
    this.interactive = getInteractiveState(this.stream, optionsArg.interactive);
    this.colors = optionsArg.colors ?? (this.interactive && !hasEnvFlag('NO_COLOR'));
  }

  public createTask(optionsArg: ISmartcliTerminalTaskOptions): SmartcliTerminalTask {
    const task = new SmartcliTerminalTask(this, optionsArg);
    this.tasks.push(task);

    if (this.interactive) {
      this.render();
    } else {
      this.writePermanentLine(`[start] ${task.job}`);
    }

    return task;
  }

  public createProcess(optionsArg: ISmartcliTerminalTaskOptions): SmartcliTerminalTask {
    return this.createTask(optionsArg);
  }

  public isInteractive(): boolean {
    return this.interactive;
  }

  public getTasks(): SmartcliTerminalTask[] {
    return [...this.tasks];
  }

  /** @internal */
  public updateTask(taskArg: SmartcliTerminalTask, messageArg?: string): void {
    if (!this.tasks.includes(taskArg)) {
      return;
    }

    if (this.interactive) {
      this.render();
    } else if (messageArg) {
      this.writePermanentLine(`[${taskArg.job}] ${messageArg}`);
    }
  }

  /** @internal */
  public completeTask(taskArg: SmartcliTerminalTask, messageArg?: string): void {
    const message = messageArg || taskArg.getLastLogLine();
    const summary = `[ok] ${taskArg.job}${message ? ` - ${message}` : ''}`;
    this.finalizeTask(taskArg, [summary]);
  }

  /** @internal */
  public failTask(taskArg: SmartcliTerminalTask, errorLinesArg: string[]): void {
    const summary = `[err] ${taskArg.job}${errorLinesArg[0] ? ` - ${errorLinesArg[0]}` : ''}`;
    const detailLines = errorLinesArg.slice(1).map((lineArg) => `  ${lineArg}`);
    this.finalizeTask(taskArg, [summary, ...detailLines]);
  }

  public clear(): void {
    if (this.interactive) {
      this.clearRenderedBlock();
    }
    this.tasks = [];
  }

  private finalizeTask(taskArg: SmartcliTerminalTask, linesArg: string[]): void {
    this.tasks = this.tasks.filter((task) => task !== taskArg);

    if (this.interactive) {
      this.clearRenderedBlock();
      this.writePermanentLines(linesArg);
      this.render();
    } else {
      this.writePermanentLines(linesArg);
    }
  }

  private render(): void {
    if (!this.interactive) {
      return;
    }

    const width = this.getLineWidth();
    const lines = this.tasks.flatMap((taskArg) => {
      return taskArg.renderPlainRows(width).map((lineArg, indexArg) => {
        const truncatedLine = truncateLine(lineArg, width);
        return indexArg === 0 ? this.colorizeStatusLabel(truncatedLine) : truncatedLine;
      });
    });

    if (this.renderedLineCount > 0) {
      this.stream.write(`\u001B[${this.renderedLineCount}F`);
    }

    const lineCount = Math.max(this.renderedLineCount, lines.length);
    for (let index = 0; index < lineCount; index++) {
      this.stream.write('\u001B[2K\r');
      if (index < lines.length) {
        this.stream.write(lines[index]);
      }
      this.stream.write('\n');
    }

    this.renderedLineCount = lines.length;
  }

  private clearRenderedBlock(): void {
    if (this.renderedLineCount === 0) {
      return;
    }

    this.stream.write(`\u001B[${this.renderedLineCount}F`);
    this.stream.write(`\u001B[${this.renderedLineCount}M`);
    this.renderedLineCount = 0;
  }

  private writePermanentLines(linesArg: string[]): void {
    for (const line of linesArg) {
      this.writePermanentLine(line);
    }
  }

  private writePermanentLine(lineArg: string): void {
    const line = this.colors ? this.colorizeStatusLabel(lineArg) : lineArg;
    this.stream.write(`${line}\n`);
  }

  private colorizeStatusLabel(lineArg: string): string {
    if (!this.colors) {
      return lineArg;
    }

    if (lineArg.startsWith('[ok]')) {
      return `${ansiCodes.green}[ok]${ansiCodes.reset}${lineArg.slice(4)}`;
    }
    if (lineArg.startsWith('[err]')) {
      return `${ansiCodes.red}[err]${ansiCodes.reset}${lineArg.slice(5)}`;
    }
    if (lineArg.startsWith('[run]')) {
      return `${ansiCodes.cyan}[run]${ansiCodes.reset}${lineArg.slice(5)}`;
    }
    if (lineArg.startsWith('[start]')) {
      return `${ansiCodes.gray}[start]${ansiCodes.reset}${lineArg.slice(7)}`;
    }
    return lineArg;
  }

  private getLineWidth(): number {
    return Math.max(20, (this.stream.columns || 80) - 1);
  }
}

export class SmartcliTerminalTask {
  public readonly job: string;
  public readonly rows: number;
  public status: TSmartcliTerminalTaskStatus = 'running';
  private terminal: SmartcliTerminal;
  private logLimit: number;
  private logLines: string[] = [];
  private errorLines: string[] = [];

  constructor(terminalArg: SmartcliTerminal, optionsArg: ISmartcliTerminalTaskOptions) {
    this.terminal = terminalArg;
    this.job = optionsArg.job;
    this.rows = Math.max(1, Math.floor(optionsArg.rows || 3));
    this.logLimit = Math.max(this.rows, Math.floor(optionsArg.logLimit || 100));
  }

  public log(messageArg: string): this {
    if (this.status !== 'running') {
      return this;
    }

    const newLines = normalizeLines(messageArg);
    this.logLines.push(...newLines);
    if (this.logLines.length > this.logLimit) {
      this.logLines.splice(0, this.logLines.length - this.logLimit);
    }

    this.terminal.updateTask(this, newLines.join('\n'));
    return this;
  }

  public update(messageArg: string): this {
    return this.log(messageArg);
  }

  public complete(messageArg?: string): this {
    if (this.status !== 'running') {
      return this;
    }

    this.status = 'completed';
    this.terminal.completeTask(this, messageArg);
    return this;
  }

  public attachError(
    errorArg: unknown,
    optionsArg: ISmartcliTerminalAttachErrorOptions = {}
  ): this {
    if (this.status !== 'running') {
      return this;
    }

    this.status = 'failed';
    this.errorLines = formatError(errorArg);

    if (optionsArg.keepOpen) {
      this.terminal.updateTask(this, this.errorLines.join('\n'));
    } else {
      this.terminal.failTask(this, this.errorLines);
    }

    return this;
  }

  public fail(errorArg: unknown): this {
    return this.attachError(errorArg);
  }

  public getLastLogLine(): string | undefined {
    return this.logLines[this.logLines.length - 1];
  }

  public getLogLines(): string[] {
    return [...this.logLines];
  }

  public getErrorLines(): string[] {
    return [...this.errorLines];
  }

  /** @internal */
  public renderPlainRows(widthArg: number): string[] {
    const statusLabel = this.status === 'failed' ? '[err]' : '[run]';
    const lines: string[] = [];
    const detailLines = this.errorLines.length > 0 ? this.errorLines : this.logLines;

    if (this.rows === 1) {
      const lastDetail = detailLines[detailLines.length - 1];
      lines.push(`${statusLabel} ${this.job}${lastDetail ? ` - ${lastDetail}` : ''}`);
      return lines;
    }

    lines.push(`${statusLabel} ${this.job}`);
    const visibleDetailLineCount = this.rows - 1;
    const visibleDetailLines = detailLines.slice(-visibleDetailLineCount);
    for (const line of visibleDetailLines) {
      lines.push(`  ${line}`);
    }

    while (lines.length < this.rows) {
      lines.push('');
    }

    return lines.map((lineArg) => truncateLine(lineArg, widthArg));
  }
}

function getDefaultStream(): ISmartcliWritable {
  const globalObject: any = globalThis as any;
  if (globalObject.process?.stdout?.write) {
    return globalObject.process.stdout;
  }

  return {
    isTTY: false,
    write: (chunkArg: string) => {
      if (typeof console !== 'undefined') {
        console.log(chunkArg.replace(/\n$/, ''));
      }
    },
  };
}

function getInteractiveState(streamArg: ISmartcliWritable, overrideArg?: boolean): boolean {
  if (typeof overrideArg === 'boolean') {
    return overrideArg;
  }

  if (!streamArg.isTTY) {
    return false;
  }

  return !(
    hasEnvFlag('CI') ||
    hasEnvFlag('GITHUB_ACTIONS') ||
    hasEnvFlag('JENKINS_URL') ||
    hasEnvFlag('GITLAB_CI') ||
    hasEnvFlag('TRAVIS') ||
    hasEnvFlag('CIRCLECI') ||
    getEnvValue('TERM') === 'dumb'
  );
}

function hasEnvFlag(nameArg: string): boolean {
  const value = getEnvValue(nameArg);
  return Boolean(value && value !== '0' && value.toLowerCase() !== 'false');
}

function getEnvValue(nameArg: string): string | undefined {
  const globalObject: any = globalThis as any;
  return globalObject.process?.env?.[nameArg];
}

function normalizeLines(messageArg: string): string[] {
  return String(messageArg)
    .split(/\r?\n/)
    .map((lineArg) => lineArg.trimEnd())
    .filter((lineArg) => lineArg.length > 0);
}

function formatError(errorArg: unknown): string[] {
  if (errorArg instanceof Error) {
    return normalizeLines(errorArg.stack || errorArg.message || errorArg.name);
  }

  if (typeof errorArg === 'string') {
    return normalizeLines(errorArg);
  }

  try {
    const jsonString = JSON.stringify(errorArg);
    return normalizeLines(jsonString === undefined ? String(errorArg) : jsonString);
  } catch {
    return [String(errorArg)];
  }
}

function truncateLine(lineArg: string, widthArg: number): string {
  if (lineArg.length <= widthArg) {
    return lineArg;
  }

  if (widthArg <= 3) {
    return lineArg.slice(0, widthArg);
  }

  return `${lineArg.slice(0, widthArg - 3)}...`;
}