// Prisma schema — the single source of truth for the database structure.
// The entity documentation lives in docs/architecture/data-model.md; keep
// both in sync when the schema evolves.

generator client {
  provider = "prisma-client-js"
}

datasource db {
  provider = "postgresql"
  url      = env("DATABASE_URL")
}

/// Typed key-value configuration for the instance (registration mode,
/// default quotas, legal pages, …). Values are validated with Zod before
/// writing; see the InstanceSettings service (issue #19).
model InstanceSetting {
  key       String   @id
  value     Json
  updatedAt DateTime @updatedAt

  @@map("instance_settings")
}

enum UserStatus {
  PENDING_VERIFICATION
  ACTIVE
  DISABLED
}

/// Account profile. Login methods live in UserIdentity (OIDC-ready,
/// ADR 0007); Site Admin is a user flag, all other roles are grants.
model User {
  id              String     @id @default(uuid())
  username        String     @unique
  email           String     @unique
  displayName     String     @map("display_name")
  locale          String     @default("en")
  isSiteAdmin     Boolean    @default(false) @map("is_site_admin")
  status          UserStatus @default(PENDING_VERIFICATION)
  emailVerifiedAt DateTime?  @map("email_verified_at")
  createdAt       DateTime   @default(now()) @map("created_at")
  lastLoginAt     DateTime?  @map("last_login_at")

  identities  UserIdentity[]
  sessions    Session[]
  authTokens  AuthToken[]
  ponds       Pond[]
  pages       Page[]
  attachments Attachment[]

  @@map("users")
}

enum PondType {
  PERSONAL
  SHARED
}

/// Top-level content container (data-model.md §ponds). Personal ponds are
/// created automatically on e-mail verification; `settings` stores only
/// deviations from the defaults (pondSettingsSchema in @dorfteich/shared).
/// `deletedAt`/`deletedBy` implement the pond-level trash (ADR 0013).
model Pond {
  id          String    @id @default(uuid())
  slug        String    @unique
  name        String
  description String    @default("")
  type        PondType
  ownerId     String    @map("owner_id")
  settings    Json      @default("{}")
  createdAt   DateTime  @default(now()) @map("created_at")
  updatedAt   DateTime  @updatedAt @map("updated_at")
  deletedAt   DateTime? @map("deleted_at")
  deletedBy   String?   @map("deleted_by")

  owner       User         @relation(fields: [ownerId], references: [id])
  usage       PondUsage?
  pages       Page[]
  attachments Attachment[]

  @@index([ownerId])
  @@map("ponds")
}

/// A wiki page (data-model.md §pages). Carries a Yjs document from day one
/// (ADR 0003) even though M2 saves it wholesale over REST; `ydocState` is
/// the merged state Y.Doc, decoded by the API to derive `PageContentCache`
/// on every save (issue #23). `sortKey` uses fractional indexing so pages
/// can be reordered without rewriting siblings (sidebar reorder is #26).
model Page {
  id        String    @id @default(uuid())
  pondId    String    @map("pond_id")
  title     String
  slug      String
  ydocState Bytes     @map("ydoc_state")
  sortKey   String    @map("sort_key")
  createdBy String    @map("created_by")
  createdAt DateTime  @default(now()) @map("created_at")
  updatedAt DateTime  @updatedAt @map("updated_at")
  deletedAt DateTime? @map("deleted_at")
  deletedBy String?   @map("deleted_by")

  pond                Pond                     @relation(fields: [pondId], references: [id])
  creator             User                     @relation(fields: [createdBy], references: [id])
  updates             PageUpdate[]
  contentCache        PageContentCache?
  attachments         Attachment[]
  versions            PageVersion[]
  pendingContributors PagePendingContributor[]

  @@unique([pondId, slug])
  @@index([pondId])
  @@map("pages")
}

/// Append log for incremental Yjs updates (data-model.md), compacted
/// periodically. Unused by M2's whole-state REST saves; the collab
/// server's persistence hooks (#35) are the first real writer.
model PageUpdate {
  id     String @id @default(uuid())
  pageId String @map("page_id")
  seq    Int
  update Bytes

  page Page @relation(fields: [pageId], references: [id], onDelete: Cascade)

  @@unique([pageId, seq])
  @@map("page_updates")
}

enum PageVersionTrigger {
  AUTO
  MANUAL
  PRE_RESTORE
}

/// Version snapshot of a page (ADR 0013, data-model.md). `ydocSnapshot` is a
/// full, self-contained encoded Yjs state — restore never depends on the
/// update log, so compaction (#40) cannot lose restorable history.
/// `contributorIds` is the set of users who edited since the previous version
/// (derived from the live session, #41). Created automatically at session end
/// and on an active-editing interval by collab, and on demand (named) by the
/// api; `PRE_RESTORE` snapshots are written before a restore (#42).
model PageVersion {
  id             String             @id @default(uuid())
  pageId         String             @map("page_id")
  ydocSnapshot   Bytes              @map("ydoc_snapshot")
  trigger        PageVersionTrigger
  label          String?
  contributorIds String[]           @map("contributor_ids")
  createdAt      DateTime           @default(now()) @map("created_at")

  page Page @relation(fields: [pageId], references: [id], onDelete: Cascade)

  @@index([pageId, createdAt])
  @@map("page_versions")
}

/// Accumulator of users who have edited a page since its last version (#41).
/// Collab flushes the current session's contributors here (deduplicated by the
/// composite key); version creation on either side reads and clears it in the
/// same transaction as writing the snapshot. Cascades on page purge (ADR 0013).
model PagePendingContributor {
  pageId String @map("page_id")
  userId String @map("user_id")

  page Page @relation(fields: [pageId], references: [id], onDelete: Cascade)

  @@id([pageId, userId])
  @@map("page_pending_contributors")
}

/// Live-session registry the collab server keeps current: one row per page
/// with an open collaboration session, refreshed by a heartbeat (issue #40).
/// The compaction job reads it to skip pages that are being edited; a stale
/// row (collab crashed without unloading) ages out via the heartbeat window,
/// so no FK to `pages` is needed and a leftover row is harmless. Collab is the
/// only writer, over raw SQL (it does not use Prisma).
model CollabOpenSession {
  pageId      String   @id @map("page_id")
  heartbeatAt DateTime @map("heartbeat_at")

  @@index([heartbeatAt])
  @@map("collab_open_sessions")
}

/// Derived plain representation refreshed on every state save (issue #23),
/// built from the Yjs state via the shared editor schema. `outline` is the
/// heading tree (`OutlineEntry[]` from @dorfteich/shared) as jsonb.
model PageContentCache {
  pageId    String   @id @map("page_id")
  plainText String   @map("plain_text")
  markdown  String
  html      String
  outline   Json
  updatedAt DateTime @updatedAt @map("updated_at")

  page Page @relation(fields: [pageId], references: [id], onDelete: Cascade)

  @@map("page_content_cache")
}

enum QuotaSubjectType {
  USER
  POND
}

/// Per-user/per-pond quota values (ADR 0011). Resolution: pond override →
/// user override → instance default (QuotaService). `value` is BigInt so
/// storage limits beyond 2 GiB fit.
model QuotaOverride {
  id          String           @id @default(uuid())
  subjectType QuotaSubjectType @map("subject_type")
  subjectId   String           @map("subject_id")
  quotaKey    String           @map("quota_key")
  value       BigInt
  updatedAt   DateTime         @updatedAt @map("updated_at")

  @@unique([subjectType, subjectId, quotaKey])
  @@map("quota_overrides")
}

/// Cached usage counters per pond, updated transactionally with the
/// guarded writes (uploads land in M2 #27, membership in M5); reconciled
/// nightly by a maintenance job (operations.md).
model PondUsage {
  pondId           String   @id @map("pond_id")
  storageBytesUsed BigInt   @default(0) @map("storage_bytes_used")
  editorCount      Int      @default(0) @map("editor_count")
  readerCount      Int      @default(0) @map("reader_count")
  updatedAt        DateTime @updatedAt @map("updated_at")

  pond Pond @relation(fields: [pondId], references: [id], onDelete: Cascade)

  @@map("pond_usage")
}

/// Uploaded file (ADR 0011, issue #27). Bytes live on the uploads volume at
/// `<uploadsDir>/<pondId>/<id>` (FileStorageService); this row carries the
/// metadata needed to serve and account for it. `pageId` starts unset —
/// images are uploaded before the page referencing them is known
/// (paste-then-insert, issue #28) — and is set on every page state save to
/// whichever page's document currently embeds the file (issue #31,
/// `PagesService.saveState`); the trash-purge job uses that link to delete
/// a purged page's files. Not touched when an image is later removed from
/// its page's content — an orphan-file sweep to reclaim those is a
/// separate future maintenance job (operations.md), not this one.
/// `deletedAt` stays unused for now — purge hard-deletes attachments
/// directly rather than soft-deleting them first — reserved for that same
/// future orphan-sweep job.
model Attachment {
  id          String    @id @default(uuid())
  pondId      String    @map("pond_id")
  pageId      String?   @map("page_id")
  fileName    String    @map("file_name")
  mimeType    String    @map("mime_type")
  sizeBytes   Int       @map("size_bytes")
  storagePath String    @map("storage_path")
  uploadedBy  String    @map("uploaded_by")
  createdAt   DateTime  @default(now()) @map("created_at")
  deletedAt   DateTime? @map("deleted_at")

  pond     Pond  @relation(fields: [pondId], references: [id])
  page     Page? @relation(fields: [pageId], references: [id])
  uploader User  @relation(fields: [uploadedBy], references: [id])

  @@index([pondId])
  @@index([pageId])
  @@map("attachments")
}

/// One row per login method. `provider` is "password" today and
/// "oidc:<issuer>" later; `credential` holds the Argon2id hash for
/// password identities.
model UserIdentity {
  id         String   @id @default(uuid())
  userId     String   @map("user_id")
  provider   String
  subject    String
  credential String?
  createdAt  DateTime @default(now()) @map("created_at")

  user User @relation(fields: [userId], references: [id], onDelete: Cascade)

  @@unique([provider, subject])
  @@index([userId])
  @@map("user_identities")
}

/// Server-side browser sessions (ADR 0007). `id` is the SHA-256 hash of
/// the opaque cookie token — the raw token is never stored.
model Session {
  id         String   @id
  userId     String   @map("user_id")
  createdAt  DateTime @default(now()) @map("created_at")
  expiresAt  DateTime @map("expires_at")
  lastSeenAt DateTime @default(now()) @map("last_seen_at")
  userAgent  String?  @map("user_agent")

  user User @relation(fields: [userId], references: [id], onDelete: Cascade)

  @@index([userId])
  @@index([expiresAt])
  @@map("sessions")
}

enum AuthTokenPurpose {
  EMAIL_VERIFICATION
  PASSWORD_RESET
}

/// Single-use, expiring tokens for e-mail flows. Stored hashed; consuming
/// sets `consumedAt` so replays are detectable.
model AuthToken {
  id         String           @id @default(uuid())
  tokenHash  String           @unique @map("token_hash")
  userId     String           @map("user_id")
  purpose    AuthTokenPurpose
  expiresAt  DateTime         @map("expires_at")
  consumedAt DateTime?        @map("consumed_at")
  createdAt  DateTime         @default(now()) @map("created_at")

  user User @relation(fields: [userId], references: [id], onDelete: Cascade)

  @@index([userId, purpose])
  @@map("auth_tokens")
}

/// Fixed-window rate-limit counters (ADR 0002: no Redis). `key` encodes
/// scope and subject, e.g. "login:ip:203.0.113.7".
model RateLimit {
  key         String   @id
  windowStart DateTime @map("window_start")
  count       Int      @default(0)

  @@map("rate_limits")
}

enum MailStatus {
  PENDING
  SENT
  FAILED
}

/// Outbox for reliable e-mail delivery with retry (issue #12).
model MailOutbox {
  id            String     @id @default(uuid())
  toAddress     String     @map("to_address")
  subject       String
  textBody      String     @map("text_body")
  htmlBody      String     @map("html_body")
  status        MailStatus @default(PENDING)
  attempts      Int        @default(0)
  nextAttemptAt DateTime   @default(now()) @map("next_attempt_at")
  lastError     String?    @map("last_error")
  createdAt     DateTime   @default(now()) @map("created_at")
  sentAt        DateTime?  @map("sent_at")

  @@index([status, nextAttemptAt])
  @@map("mail_outbox")
}

enum JobStatus {
  IDLE
  RUNNING
  FAILED
}

/// Generic maintenance-job bookkeeping (data-model.md, operations.md;
/// issue #31). One row per named job; `SchedulerService` is the only
/// writer. `status`/`lockedAt` double as the run-mutex: claiming a due job
/// is a single atomic `UPDATE ... WHERE status != 'RUNNING'`, which is safe
/// under concurrent processes without needing a session-scoped advisory
/// lock (Prisma doesn't guarantee one connection across separate calls).
/// `lastRunAt` is what makes the schedule survive an api restart — cadence
/// is computed from it, not from an in-memory timer start time. The mail
/// outbox worker (#12) predates this table and still runs its own loop;
/// folding it in is left for whenever that file is next touched, not this
/// issue's job to do.
model Job {
  name           String    @id
  cadenceSeconds Int       @map("cadence_seconds")
  status         JobStatus @default(IDLE)
  lastRunAt      DateTime? @map("last_run_at")
  lockedAt       DateTime? @map("locked_at")
  lastError      String?   @map("last_error")
  updatedAt      DateTime  @updatedAt @map("updated_at")

  @@map("jobs")
}