import { DomainError } from '@devrunbook/domain'

import {
  authorizeWorkspaceAction,
  type AuthenticatedActor,
  type WorkspaceAuthorizationLookup,
} from '../auth/workspace-authorization'
import {
  assessLifecycleEvidence,
  type LifecycleEvidence,
  type LifecycleEvidencePolicy,
  type PlaybookLifecycle,
} from '../quality/static-quality-evaluation'
import {
  formatPrivatePlaybookDraftEtag,
  parsePrivatePlaybookDraftEtag,
  type PrivatePlaybookDraft,
} from './private-playbook-drafts'

const semverPattern =
  /^(?:0|[1-9]\d*)\.(?:0|[1-9]\d*)\.(?:0|[1-9]\d*)(?:-[0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*)?(?:\+[0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*)?$/u

export interface PrivatePlaybookPublicationCandidate {
  readonly draft: PrivatePlaybookDraft
  /** Trusted evidence assembled from persisted validation and evaluation rows. */
  readonly evidence: LifecycleEvidence
  readonly policy: LifecycleEvidencePolicy
}

export interface PrivatePlaybookPublicationStore {
  findPublicationCandidate(
    workspaceId: string,
    versionId: string,
  ): Promise<PrivatePlaybookPublicationCandidate | null>
  publishDraft(request: {
    readonly workspaceId: string
    readonly versionId: string
    readonly publishedBy: string
    readonly expectedRevision: number
    readonly expectedDigest: string
    readonly lifecycle: Exclude<PlaybookLifecycle, 'draft' | 'battle-tested'>
    readonly now: Date
  }): Promise<PrivatePlaybookDraft | null>
  createNextDraft(request: {
    readonly workspaceId: string
    readonly sourceVersionId: string
    readonly semanticVersion: string
    readonly createdBy: string
    readonly now: Date
  }): Promise<PrivatePlaybookDraft | null>
}

export interface PrivatePlaybookPublicationDependencies {
  readonly authorization: WorkspaceAuthorizationLookup
  readonly store: PrivatePlaybookPublicationStore
  readonly now: () => Date
}

export interface PrivatePlaybookPublicationRequest {
  readonly actor: AuthenticatedActor | null
  readonly workspaceId: string
  readonly versionId: string
  readonly expectedEtag: string
  readonly lifecycle: Exclude<PlaybookLifecycle, 'draft' | 'battle-tested'>
}

function conflict(message: string, details?: Record<string, unknown>): never {
  throw new DomainError('private_playbook_publish_conflict', message, details)
}

function notFound(): never {
  throw new DomainError(
    'private_playbook_not_found',
    'Private playbook not found',
  )
}

async function authorizeWrite(
  dependencies: PrivatePlaybookPublicationDependencies,
  actor: AuthenticatedActor | null,
  workspaceId: string,
): Promise<string> {
  const context = await authorizeWorkspaceAction(dependencies.authorization, {
    actor,
    workspaceId,
    action: 'write',
  })
  return context.userId
}

function hasChangelog(draft: PrivatePlaybookDraft): boolean {
  return draft.files.some(
    (file) => file.role === 'changelog' && file.content.byteLength > 0,
  )
}

export async function publishPrivatePlaybookVersion(
  dependencies: PrivatePlaybookPublicationDependencies,
  request: PrivatePlaybookPublicationRequest,
): Promise<{ readonly version: PrivatePlaybookDraft; readonly etag: string }> {
  const publishedBy = await authorizeWrite(
    dependencies,
    request.actor,
    request.workspaceId,
  )
  const expected = parsePrivatePlaybookDraftEtag(request.expectedEtag)
  const candidate = await dependencies.store.findPublicationCandidate(
    request.workspaceId,
    request.versionId,
  )
  if (!candidate) notFound()
  if (candidate.draft.publishedAt !== null) {
    conflict('Published playbook versions are immutable; create a new version.')
  }
  if (
    candidate.draft.draftRevision !== expected.revision ||
    candidate.draft.draftDigest !== expected.digest
  ) {
    conflict('The draft changed since it was reviewed.', {
      currentEtag: formatPrivatePlaybookDraftEtag(
        candidate.draft.draftRevision,
        candidate.draft.draftDigest,
      ),
    })
  }
  if (!hasChangelog(candidate.draft)) {
    throw new DomainError(
      'private_playbook_changelog_required',
      'A non-empty changelog is required before publication',
    )
  }

  const assessment = assessLifecycleEvidence(
    request.lifecycle,
    candidate.evidence,
    candidate.policy,
    dependencies.now(),
  )
  if (!assessment.eligible) {
    throw new DomainError(
      'private_playbook_quality_evidence_insufficient',
      'The requested lifecycle exceeds current quality evidence',
      { requirements: assessment.requirements, findings: assessment.findings },
    )
  }

  const version = await dependencies.store.publishDraft({
    workspaceId: request.workspaceId,
    versionId: request.versionId,
    publishedBy,
    expectedRevision: expected.revision,
    expectedDigest: expected.digest,
    lifecycle: request.lifecycle,
    now: dependencies.now(),
  })
  if (!version) notFound()
  return {
    version,
    etag: formatPrivatePlaybookDraftEtag(
      version.draftRevision,
      version.draftDigest,
    ),
  }
}

export async function createNextPrivatePlaybookVersion(
  dependencies: PrivatePlaybookPublicationDependencies,
  request: {
    readonly actor: AuthenticatedActor | null
    readonly workspaceId: string
    readonly sourceVersionId: string
    readonly semanticVersion: string
  },
): Promise<{ readonly draft: PrivatePlaybookDraft; readonly etag: string }> {
  const createdBy = await authorizeWrite(
    dependencies,
    request.actor,
    request.workspaceId,
  )
  if (!semverPattern.test(request.semanticVersion)) {
    throw new DomainError(
      'private_playbook_version_invalid',
      'A valid Semantic Version is required',
    )
  }
  const source = await dependencies.store.findPublicationCandidate(
    request.workspaceId,
    request.sourceVersionId,
  )
  if (!source) notFound()
  if (source.draft.publishedAt === null) {
    conflict('Only an immutable published version can be used as the source.')
  }
  if (source.draft.semanticVersion === request.semanticVersion) {
    conflict('The new version must use a different Semantic Version.')
  }
  const draft = await dependencies.store.createNextDraft({
    workspaceId: request.workspaceId,
    sourceVersionId: request.sourceVersionId,
    semanticVersion: request.semanticVersion,
    createdBy,
    now: dependencies.now(),
  })
  if (!draft) notFound()
  return {
    draft,
    etag: formatPrivatePlaybookDraftEtag(
      draft.draftRevision,
      draft.draftDigest,
    ),
  }
}