import { randomUUID } from 'node:crypto';
import { EventEmitter } from 'node:events';
import { resolve } from 'node:path';
import {
  prepareProjectRelease,
  ProjectReleaseBuildError,
  type PreparedRelease,
  type ReleaseBuildProgress,
  type ReleaseBuildRuntimeContext,
} from './project-release-builder';

type ReleaseJobPackageSummary = Omit<PreparedRelease['sourceArchive']['summary'], 'archivePath'>;

export type ReleaseJobState = 'queued' | 'running' | 'complete' | 'failed' | 'cancelled';

export type ReleaseJobStatus = {
  jobId: string;
  projectId: string;
  state: ReleaseJobState;
  phase: ReleaseBuildProgress['phase'] | 'queued';
  percent: number;
  errorCode?: string;
  errorMessage?: string;
  result?: {
    package: ReleaseJobPackageSummary;
    contract: PreparedRelease['contract'];
  };
};

/**
 * A utility-process build only needs to return the immutable package summary
 * and contract to Main. Archive bytes stay in the worker and are discarded
 * before it exits, so a release status request cannot duplicate a large build
 * buffer in the browser process.
 */
export type ReleaseJobPreparation = {
  sourceArchive: Pick<PreparedRelease['sourceArchive'], 'summary'>;
  contract: PreparedRelease['contract'];
  dispose(): Promise<void>;
};

export type ReleaseJobPrepare = (input: {
  projectPath: string;
  clientVersion: string;
  signal?: AbortSignal;
  onProgress?: (progress: ReleaseBuildProgress) => void;
  runtimeContext?: ReleaseBuildRuntimeContext;
}) => Promise<PreparedRelease | ReleaseJobPreparation>;

type ReleaseJobRecord = ReleaseJobStatus & {
  controller: AbortController;
  projectPath: string;
  projectKey: string;
};

export type ReleaseJobManagerOptions = {
  prepare?: ReleaseJobPrepare;
  acquireLease?: (lease: { id: string; kind: string }) => () => void;
  dispose?: () => void;
};

/**
 * Owns the asynchronous local release build contract. The manager is kept
 * independent of HTTP so Main can expose start/progress/status/cancel over
 * either Host API or IPC without putting project state in the Renderer.
 */
export class ReleaseJobManager extends EventEmitter {
  private readonly jobs = new Map<string, ReleaseJobRecord>();
  private readonly activeProjects = new Map<string, string>();
  private readonly prepare: ReleaseJobPrepare;

  constructor(private readonly options: ReleaseJobManagerOptions = {}) {
    super();
    this.prepare = options.prepare ?? prepareProjectRelease;
  }

  start(input: { projectId: string; projectPath: string; clientVersion: string }): ReleaseJobStatus {
    const projectKey = resolve(input.projectPath);
    if (this.activeProjects.has(projectKey)) {
      throw new ProjectReleaseBuildError('LOCAL_BUILD_BUSY');
    }
    const jobId = randomUUID();
    const record: ReleaseJobRecord = {
      jobId,
      projectId: input.projectId,
      projectPath: input.projectPath,
      projectKey,
      state: 'queued',
      phase: 'queued',
      percent: 0,
      controller: new AbortController(),
    };
    this.jobs.set(jobId, record);
    this.activeProjects.set(projectKey, jobId);
    void this.run(record, input.clientVersion);
    return this.snapshot(record);
  }

  get(jobId: string): ReleaseJobStatus | null {
    const record = this.jobs.get(jobId);
    return record ? this.snapshot(record) : null;
  }

  cancel(jobId: string): ReleaseJobStatus | null {
    const record = this.jobs.get(jobId);
    if (!record) return null;
    if (record.state === 'queued' || record.state === 'running') {
      record.controller.abort();
      this.update(record, {
        state: 'cancelled',
        errorCode: 'LOCAL_BUILD_CANCELLED',
        errorMessage: '构建已取消。',
      });
    }
    return this.snapshot(record);
  }

  dispose(): void {
    for (const record of this.jobs.values()) record.controller.abort();
    this.jobs.clear();
    this.activeProjects.clear();
    this.options.dispose?.();
    this.removeAllListeners();
  }

  private async run(record: ReleaseJobRecord, clientVersion: string): Promise<void> {
    const releaseLease = this.options.acquireLease?.({ id: `release-job:${record.jobId}`, kind: 'release-build' });
    let prepared: PreparedRelease | null = null;
    this.update(record, { state: 'running', phase: 'packaging', percent: 1 });
    try {
      prepared = await this.prepare({
        projectPath: record.projectPath,
        clientVersion,
        signal: record.controller.signal,
        onProgress: (progress) => this.update(record, {
          state: record.controller.signal.aborted ? 'cancelled' : 'running',
          phase: progress.phase,
          percent: progress.percent,
        }),
      });
      if (record.controller.signal.aborted) {
        this.update(record, {
          state: 'cancelled',
          errorCode: 'LOCAL_BUILD_CANCELLED',
          errorMessage: '构建已取消。',
        });
        return;
      }
      this.update(record, {
        state: 'complete',
        phase: 'complete',
        percent: 100,
        result: {
          package: (() => {
            const { archivePath: _archivePath, ...summary } = prepared.sourceArchive.summary;
            return summary;
          })(),
          contract: prepared.contract,
        },
      });
    } catch (error) {
      const code = error instanceof ProjectReleaseBuildError
        ? error.code
        : 'LOCAL_BUILD_FAILED';
      const cancelled = code === 'LOCAL_BUILD_CANCELLED' || record.controller.signal.aborted;
      this.update(record, {
        state: cancelled ? 'cancelled' : 'failed',
        errorCode: cancelled ? 'LOCAL_BUILD_CANCELLED' : code,
        errorMessage: cancelled ? '构建已取消。' : (error instanceof Error ? error.message : String(error)),
      });
    } finally {
      releaseLease?.();
      await prepared?.dispose().catch(() => undefined);
      if (this.activeProjects.get(record.projectKey) === record.jobId) {
        this.activeProjects.delete(record.projectKey);
      }
    }
  }

  private update(record: ReleaseJobRecord, patch: Partial<ReleaseJobStatus>): void {
    Object.assign(record, patch);
    const status = this.snapshot(record);
    this.emit('status', status);
    this.emit(`status:${record.jobId}`, status);
  }

  private snapshot(record: ReleaseJobRecord): ReleaseJobStatus {
    const {
      controller: _controller,
      projectKey: _projectKey,
      projectPath: _projectPath,
      ...status
    } = record;
    return structuredClone(status);
  }
}