/** Coverage shard definitions for the GitHub Actions source-test lanes. */

/** A coverage lane that owns complete package roots and optional cross-package tests. */
export interface CoverageShard {
  /** Stable lane identifier passed through `DSH_COVERAGE_SHARD`. */
  name: string
  /** Group or package paths below `packages/` whose tests and source coverage belong to the lane. */
  packageRoots: readonly string[]
  /** Additional test roots needed for cross-package behavior or repository scripts. */
  extraTestRoots?: readonly string[]
}

/** Exhaustive, non-overlapping ownership of workspace packages in coverage CI. */
export const coverageShards = [
  {
    name: 'core-loop',
    packageRoots: ['core/agent', 'core/agent-loop', 'core/tools'],
  },
  {
    name: 'state-session',
    packageRoots: [
      'core/session',
      'core/scope',
      'core/system-prompt',
      'context',
      'session-persistence',
      'session-query',
      'support/invariants',
    ],
    extraTestRoots: [
      'packages/examples/cli-demo/tests',
      'packages/llm/token-meter/tests',
      'scripts',
    ],
  },
  {
    name: 'models',
    packageRoots: ['llm', 'compact'],
  },
  {
    name: 'session-title',
    packageRoots: ['session-title'],
  },
  {
    name: 'integrations',
    packageRoots: ['hooks/hook-protocol', 'lsp', 'mcp', 'hooks/hooks-claude'],
  },
  {
    name: 'sdk-capabilities',
    packageRoots: [
      'sdk',
      'hooks/hooks-codex',
      'web',
      'skill',
      'spill',
      'util',
      'guard',
      'todo',
      'timeout',
    ],
  },
  {
    name: 'interfaces',
    packageRoots: ['ui', 'examples', 'goal'],
    extraTestRoots: ['examples'],
  },
  { name: 'execution', packageRoots: ['fs', 'bash', 'sandbox', 'code-runtime'] },
  {
    name: 'workflow',
    packageRoots: ['workflow/workflow', 'workflow/tool-workflow', 'workflow/tool-ralph'],
  },
  {
    name: 'workflow-worker',
    packageRoots: ['workflow/workflow-workerthread'],
  },
  { name: 'delegation', packageRoots: ['subagent', 'tasks'] },
  {
    name: 'repository',
    packageRoots: [
      'cordis',
      'support/acp-snapshot',
      'support/agent-loop-testkit',
      'support/llm-replay',
      'support/loader-smoke',
    ],
  },
] as const satisfies readonly CoverageShard[]

/**
 * Build Vitest filters and coverage include globs for one source-test lane.
 *
 * @param name Stable shard name from {@link coverageShards}.
 * @returns Positional test roots followed by per-group coverage include flags.
 */
export function coverageArgs(name: string): string[] {
  const shard = coverageShards.find(candidate => candidate.name === name)
  if (shard === undefined) {
    throw new Error(`run-gates: unknown DSH_COVERAGE_SHARD ${JSON.stringify(name)}.`)
  }

  // Vitest positional filters are substrings; the trailing separator keeps
  // prefix-named sibling packages out of each lane.
  const testRoots = new Set([
    ...shard.packageRoots.map(packageRoot => `packages/${packageRoot}/`),
    ...('extraTestRoots' in shard ? shard.extraTestRoots.map(testRoot => `${testRoot}/`) : []),
    'scripts/test-invariants.spec.ts',
  ])
  return [
    ...testRoots,
    ...shard.packageRoots.map(packageRoot => packageRoot.includes('/')
      ? `--coverage.include=packages/${packageRoot}/src/**/*.ts`
      : `--coverage.include=packages/${packageRoot}/*/src/**/*.ts`),
  ]
}