import {
  customElement,
  DeesElement,
  type TemplateResult,
  html,
  property,
  css,
} from '@design.estate/dees-element';
import { demoFunc } from './dees-updater.demo.js';
import {
  DeesStepper,
  type IStep,
  type IStepProgressState,
} from '../../00group-layout/dees-stepper/dees-stepper.js';

export type TDeesUpdaterSuccessAction = 'close' | 'reload';

export interface IDeesUpdaterOptions {
  currentVersion?: string;
  updatedVersion?: string;
  moreInfoUrl?: string;
  changelogUrl?: string;
  successAction?: TDeesUpdaterSuccessAction;
  successDelayMs?: number;
  successActionLabel?: string;
  onSuccessAction?: () => Promise<void> | void;
}

declare global {
  interface HTMLElementTagNameMap {
    'dees-updater': DeesUpdater;
  }
}

@customElement('dees-updater')
export class DeesUpdater extends DeesElement {
  public static demo = demoFunc;
  public static demoGroups = ['Utility'];

  public static async createAndShow(optionsArg: IDeesUpdaterOptions = {}) {
    const updater = new DeesUpdater();
    updater.currentVersion = optionsArg.currentVersion ?? '';
    updater.updatedVersion = optionsArg.updatedVersion ?? '';
    updater.moreInfoUrl = optionsArg.moreInfoUrl ?? '';
    updater.changelogUrl = optionsArg.changelogUrl ?? '';
    updater.successAction = optionsArg.successAction ?? 'close';
    updater.successDelayMs = optionsArg.successDelayMs ?? 10000;
    updater.successActionLabel = optionsArg.successActionLabel ?? '';
    updater.onSuccessAction = optionsArg.onSuccessAction ?? null;
    document.body.appendChild(updater);
    await updater.show();
    return updater;
  }

  @property({
    type: String,
  })
  accessor currentVersion = '';

  @property({
    type: String,
  })
  accessor updatedVersion = '';

  @property({
    type: String,
  })
  accessor moreInfoUrl = '';

  @property({
    type: String,
  })
  accessor changelogUrl = '';

  @property({
    type: String,
  })
  accessor successAction: TDeesUpdaterSuccessAction = 'close';

  @property({
    type: Number,
  })
  accessor successDelayMs = 10000;

  @property({
    type: String,
  })
  accessor successActionLabel = '';

  private stepper: DeesStepper | null = null;
  private progressStep: IStep | null = null;
  private showPromise: Promise<void> | null = null;
  private onSuccessAction: (() => Promise<void> | void) | null = null;

  public static styles = [
    css`
      :host {
        display: none;
      }
    `,
  ];

  public render(): TemplateResult {
    return html``;
  }

  public async connectedCallback(): Promise<void> {
    await super.connectedCallback();
    void this.show();
  }

  public async show(): Promise<void> {
    if (this.stepper?.isConnected) {
      return;
    }

    if (this.showPromise) {
      return this.showPromise;
    }

    this.showPromise = this.openStepperFlow();

    try {
      await this.showPromise;
    } finally {
      this.showPromise = null;
    }
  }

  public updateProgress(progressStateArg: Partial<IStepProgressState>) {
    if (!this.stepper || !this.progressStep) {
      return;
    }

    this.stepper.updateProgressStep(progressStateArg, this.progressStep);
  }

  public appendProgressLine(lineArg: string) {
    if (!this.stepper || !this.progressStep) {
      return;
    }

    this.stepper.appendProgressStepLine(lineArg, this.progressStep);
  }

  public markUpdateError(messageArg: string) {
    this.appendProgressLine(`Error: ${messageArg}`);
    this.updateProgress({
      indeterminate: false,
      statusText: messageArg,
    });
  }

  public async markUpdateReady() {
    if (!this.stepper || !this.progressStep) {
      return;
    }

    this.stepper.updateProgressStep(
      {
        percentage: 100,
        indeterminate: false,
        statusText: 'Update ready.',
      },
      this.progressStep,
    );
    this.stepper.appendProgressStepLine('Update ready', this.progressStep);

    if (this.stepper.selectedStep === this.progressStep) {
      this.stepper.goNext();
    }
  }

  public async destroy() {
    const stepper = this.stepper;
    this.stepper = null;
    this.progressStep = null;

    if (stepper?.isConnected) {
      await stepper.destroy();
    }

    if (this.parentElement) {
      this.parentElement.removeChild(this);
    }
  }

  private async openStepperFlow() {
    const { steps, progressStep } = this.createUpdaterSteps();
    this.progressStep = progressStep;
    this.stepper = await DeesStepper.createAndShow({
      steps,
      cancelable: false,
    });
  }

  private createUpdaterSteps(): { steps: IStep[]; progressStep: IStep } {
    const infoMenuOptions = this.getLinkMenuOptions();
    const progressStep: IStep = {
      title: 'Updating the application',
      content: this.renderProgressContent(),
      progressStep: {
        label: this.getProgressLabel(),
        percentage: 5,
        indeterminate: true,
        statusRows: 4,
        statusText: 'Preparing update...',
        terminalLines: ['Preparing update'],
      },
      menuOptions: infoMenuOptions.length > 0 ? infoMenuOptions : undefined,
    };

    const readyStep: IStep = {
      title: this.updatedVersion ? `Version ${this.updatedVersion} ready` : 'Update ready',
      content: this.renderReadyContent(),
      progressStep: {
        label: this.getSuccessCountdownLabel(this.getSuccessDelaySeconds()),
        percentage: 0,
        indeterminate: false,
        showPercentage: false,
        statusRows: 2,
        statusText: this.getSuccessCountdownStatus(this.getSuccessDelaySeconds()),
      },
      validationFunc: async (stepper, _htmlElement, signal) => {
        await this.runSuccessCountdown(stepper, readyStep, signal);
      },
    };

    return {
      steps: [progressStep, readyStep],
      progressStep,
    };
  }

  private getProgressLabel(): string {
    if (this.currentVersion && this.updatedVersion) {
      return `${this.currentVersion} -> ${this.updatedVersion}`;
    }

    if (this.updatedVersion) {
      return `Preparing ${this.updatedVersion}`;
    }

    return 'Application update';
  }

  private getSuccessDelaySeconds(): number {
    return Math.max(1, Math.ceil(this.successDelayMs / 1000));
  }

  private getSuccessActionDisplayLabel(): string {
    if (this.successActionLabel) {
      return this.successActionLabel;
    }

    if (this.onSuccessAction) {
      return 'Continuing automatically';
    }

    if (this.successAction === 'reload') {
      return 'Reloading application';
    }

    return 'Closing updater';
  }

  private getSuccessCountdownLabel(secondsArg: number): string {
    return `${this.getSuccessActionDisplayLabel()} in ${secondsArg}s`;
  }

  private getSuccessCountdownStatus(secondsArg: number): string {
    const secondLabel = secondsArg === 1 ? 'second' : 'seconds';
    return `${this.getSuccessActionDisplayLabel()} in ${secondsArg} ${secondLabel}.`;
  }

  private getSuccessActionNowLabel(): string {
    return `${this.getSuccessActionDisplayLabel()} now...`;
  }

  private getLinkMenuOptions() {
    const menuOptions: Array<{ name: string; action: () => Promise<void> }> = [];

    if (this.moreInfoUrl) {
      menuOptions.push({
        name: 'More info',
        action: async () => {
          this.openExternalUrl(this.moreInfoUrl);
        },
      });
    }

    if (this.changelogUrl) {
      menuOptions.push({
        name: 'Changelog',
        action: async () => {
          this.openExternalUrl(this.changelogUrl);
        },
      });
    }

    return menuOptions;
  }

  private renderProgressContent(): TemplateResult {
    return html`
      <div style="display: grid; gap: 12px; color: var(--dees-color-text-secondary); line-height: 1.6;">
        <p style="margin: 0; text-align: center;">
          Downloading and applying the latest application release.
          ${this.currentVersion && this.updatedVersion
            ? html`Moving from <strong>${this.currentVersion}</strong> to <strong>${this.updatedVersion}</strong>.`
            : this.updatedVersion
              ? html`Preparing <strong>${this.updatedVersion}</strong>.`
              : ''}
        </p>
        <p style="margin: 0; text-align: center; font-size: 13px; color: var(--dees-color-text-muted);">
          The updater advances automatically once the new build is installed and verified.
        </p>
      </div>
    `;
  }

  private renderReadyContent(): TemplateResult {
    const successDelaySeconds = this.getSuccessDelaySeconds();

    return html`
      <div style="display: grid; gap: 12px; color: var(--dees-color-text-secondary); line-height: 1.6;">
        <p style="margin: 0; text-align: center;">
          ${this.updatedVersion
            ? html`Version <strong>${this.updatedVersion}</strong> is ready to use.`
            : 'The new version is ready to use.'}
        </p>
        <p style="margin: 0; text-align: center; font-size: 13px; color: var(--dees-color-text-muted);">
          Configured next action: ${this.getSuccessActionDisplayLabel()}. It runs automatically in ${successDelaySeconds} seconds.
        </p>
      </div>
    `;
  }

  private async runSuccessCountdown(
    stepperArg: DeesStepper,
    stepArg: IStep,
    signal?: AbortSignal,
  ): Promise<void> {
    const totalDuration = Math.max(1000, this.successDelayMs);
    const startTime = Date.now();

    while (!signal?.aborted) {
      const elapsed = Math.min(totalDuration, Date.now() - startTime);
      const remainingMilliseconds = Math.max(0, totalDuration - elapsed);
      const remainingSeconds = Math.max(0, Math.ceil(remainingMilliseconds / 1000));

      stepperArg.updateProgressStep(
        {
          label: remainingMilliseconds > 0
            ? this.getSuccessCountdownLabel(remainingSeconds)
            : this.getSuccessActionNowLabel(),
          percentage: (elapsed / totalDuration) * 100,
          indeterminate: false,
          showPercentage: false,
          statusText: remainingMilliseconds > 0
            ? this.getSuccessCountdownStatus(remainingSeconds)
            : this.getSuccessActionNowLabel(),
        },
        stepArg,
      );

      if (remainingMilliseconds <= 0) {
        break;
      }

      const completed = await this.waitForCountdownTick(100, signal);
      if (!completed) {
        return;
      }
    }

    await this.runConfiguredSuccessAction();
  }

  private async waitForCountdownTick(timeoutArg: number, signal?: AbortSignal): Promise<boolean> {
    return new Promise((resolve) => {
      let completed = false;

      const finish = (result: boolean) => {
        if (completed) {
          return;
        }

        completed = true;
        if (signal) {
          signal.removeEventListener('abort', handleAbort);
        }
        resolve(result);
      };

      const handleAbort = () => {
        window.clearTimeout(timeoutId);
        finish(false);
      };

      const timeoutId = window.setTimeout(() => {
        finish(true);
      }, timeoutArg);

      if (signal) {
        signal.addEventListener('abort', handleAbort, { once: true });
      }
    });
  }

  private async runConfiguredSuccessAction(): Promise<void> {
    if (this.onSuccessAction) {
      await this.onSuccessAction();
      return;
    }

    if (this.successAction === 'reload') {
      await this.destroy();
      window.location.reload();
      return;
    }

    await this.destroy();
  }

  private openExternalUrl(urlArg: string) {
    window.open(urlArg, '_blank', 'noopener,noreferrer');
  }
}