/**
 * Workspace runner for APOPHIS CLI commands.
 *
 * Responsibilities:
 * - Fan out a command across all workspace packages
 * - Collect per-package artifacts with package attribution
 * - Aggregate results into a single workspace result
 * - Support json, ndjson, and human output formats
 * - Preserve exit codes: fail if any package fails
 *
 * Architecture:
 * - Dependency injection: all dependencies passed explicitly
 * - No optional imports — everything is required or injected
 * - Inline comments for documentation
 */

import type { CliContext } from './context.js';
import { findWorkspacePackages } from './config-loader.js';
import type { Artifact, WorkspaceRun, WorkspaceResult, ExitCode } from './types.js';
import { SUCCESS } from './exit-codes.js';

// ---------------------------------------------------------------------------
// Types
// ---------------------------------------------------------------------------

export type RunCommandFn = (ctx: CliContext) => Promise<{ exitCode: number; artifact?: Artifact; warnings?: string[] }>;

export interface WorkspaceRunnerDeps {
  runCommand: RunCommandFn;
  findPackages?: (cwd: string) => string[];
}

// ---------------------------------------------------------------------------
// Workspace package discovery
// ---------------------------------------------------------------------------

/**
 * Discover workspace packages using config-loader.
 * Falls back to empty array if no workspaces found.
 */
function discoverPackages(cwd: string, findPackages?: (cwd: string) => string[]): string[] {
  if (findPackages) {
    return findPackages(cwd);
  }
  return findWorkspacePackages(cwd);
}

// ---------------------------------------------------------------------------
// Package name extraction
// ---------------------------------------------------------------------------

/**
 * Extract package name from absolute path.
 * Uses basename of the directory.
 */
function getPackageName(pkgPath: string): string {
  const parts = pkgPath.split('/');
  return parts[parts.length - 1] || 'unknown';
}

// ---------------------------------------------------------------------------
// Workspace execution
// ---------------------------------------------------------------------------

/**
 * Run a command across all workspace packages.
 *
 * Flow:
 * 1. Discover workspace packages
 * 2. Run command for each package with package-attributed context
 * 3. Collect artifacts and warnings
 * 4. Determine overall exit code (fail if any package fails)
 * 5. Return workspace result with all runs
 */
export async function runWorkspace(
  deps: WorkspaceRunnerDeps,
  ctx: CliContext,
): Promise<WorkspaceResult> {
  const packages = discoverPackages(ctx.cwd, deps.findPackages);

  if (packages.length === 0) {
    return {
      exitCode: SUCCESS as ExitCode,
      runs: [],
      message: 'No workspace packages found.',
    };
  }

  const runs: WorkspaceRun[] = [];
  let overallExitCode = SUCCESS;
  const allWarnings: string[] = [];

  for (const pkgPath of packages) {
    const pkgName = getPackageName(pkgPath);

    // Create a context scoped to this package's directory
    const pkgCtx: CliContext = {
      ...ctx,
      cwd: pkgPath,
    };

    const pkgResult = await deps.runCommand(pkgCtx);

    if (pkgResult.artifact) {
      // Attach package name to artifact for attribution
      const attributedArtifact: Artifact = {
        ...pkgResult.artifact,
        package: pkgName,
      };
      runs.push({
        package: pkgName,
        cwd: pkgPath,
        artifact: attributedArtifact,
      });
    }

    if (pkgResult.exitCode !== SUCCESS) {
      overallExitCode = pkgResult.exitCode as ExitCode;
    }

    if (pkgResult.warnings) {
      allWarnings.push(...pkgResult.warnings.map(w => `[${pkgName}] ${w}`));
    }
  }

  return {
    exitCode: overallExitCode as ExitCode,
    runs,
    warnings: allWarnings.length > 0 ? allWarnings : undefined,
  };
}

// ---------------------------------------------------------------------------
// Output formatting
// ---------------------------------------------------------------------------

/**
 * Format workspace results for human-readable output.
 * Shows per-package summary with pass/fail status.
 */
export function formatWorkspaceHuman(result: WorkspaceResult): string {
  const lines: string[] = [];
  lines.push('Workspace results');
  lines.push('');

  for (const run of result.runs) {
    const a = run.artifact;
    const status = a.exitReason === 'success' ? '✓' : '✗';
    lines.push(`  ${status} ${run.package}: ${a.summary.passed}/${a.summary.total} passed`);
    if (a.summary.failed > 0) {
      lines.push(`    ${a.summary.failed} failed`);
    }
  }

  lines.push('');
  lines.push(`Overall: ${result.exitCode === SUCCESS ? 'passed' : 'failed'}`);

  return lines.join('\n');
}

/**
 * Format workspace results as JSON.
 * Includes all runs with full artifacts.
 */
export function formatWorkspaceJson(result: WorkspaceResult): string {
  return JSON.stringify({
    exitCode: result.exitCode,
    runs: result.runs.map(r => ({
      package: r.package,
      cwd: r.cwd,
      artifact: r.artifact,
    })),
    warnings: result.warnings,
  }, null, 2);
}

/**
 * Format workspace results as NDJSON.
 * Emits one event per package plus a completion event.
 */
export function formatWorkspaceNdjson(result: WorkspaceResult): string {
  const lines: string[] = [];

  for (const run of result.runs) {
    lines.push(JSON.stringify({
      type: 'workspace.run.completed',
      package: run.package,
      cwd: run.cwd,
      summary: run.artifact.summary,
      exitReason: run.artifact.exitReason,
    }));
  }

  lines.push(JSON.stringify({
    type: 'workspace.completed',
    exitCode: result.exitCode,
    packages: result.runs.length,
  }));

  return lines.join('\n');
}