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

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

enum UserRole {
  ADMIN
  AGENT
  CUSTOMER
}

model User {
  id           String   @id @default(uuid())
  email        String   @unique
  name         String
  role         UserRole @default(CUSTOMER)
  passwordHash String // bcryptjs hash — never the plaintext password; see
  // specs/010-identity-auth/data-model.md
  active       Boolean  @default(true)
  createdAt    DateTime @default(now())
  updatedAt    DateTime @updatedAt

  agent Agent?

  @@map("users")
}

model Product {
  id                String   @id @default(cuid())
  externalProductId String   @unique // reference into SaaS, not authoritative — see
  // .specify/memory/constitution.md Principle I
  name              String
  supportEnabled    Boolean  @default(true)
  status            String   @default("active") // active | suspended | deprecated
  createdAt         DateTime @default(now())
  updatedAt         DateTime @updatedAt

  categories           Category[]
  integration          ProductIntegration?
  problems             Problem[]
  tickets              Ticket[]
  knowledgeEntries     KnowledgeEntry[]
  errorCodes           ErrorCode[]
  knownIssues          KnownIssue[]
  runbooks             Runbook[]
  aiConfidencePolicies AIConfidencePolicy[]
  slaPolicies          SLAPolicy[]
  escalationPolicies   EscalationPolicy[]

  @@map("products")
}

model ProductIntegration {
  id        String  @id @default(cuid())
  productId String  @unique
  product   Product @relation(fields: [productId], references: [id])

  // AES-256-GCM-encrypted secret (ciphertext, not plaintext) — see
  // specs/002-saas-integration/research.md "Credential storage"
  credentialRef               String
  previousCredentialRef       String?
  previousCredentialExpiresAt DateTime?
  authMechanism               String    @default("signed_token") // free-text — not an enum,
  // so a future integration can use oauth2_client_credentials or mtls without a migration
  allowedScope                Json // { tenantIds?: string[], allowAnyTenant?: boolean }
  rateLimitPerMinute          Int       @default(60)
  rateLimitPerUserPerMinute   Int       @default(20)
  status                      String    @default("active") // active | suspended
  rotatedAt                   DateTime?
  revokedAt                   DateTime?
  createdAt                   DateTime  @default(now())

  @@map("product_integrations")
}

model CustomerReference {
  id               String   @id @default(cuid())
  externalUserId   String
  externalTenantId String
  createdAt        DateTime @default(now())

  tickets Ticket[]

  @@unique([externalUserId, externalTenantId])
  @@map("customer_references")
}

model Category {
  id          String   @id @default(uuid())
  productId   String
  name        String
  description String?
  createdAt   DateTime @default(now())
  updatedAt   DateTime @updatedAt

  product     Product     @relation(fields: [productId], references: [id], onDelete: Cascade)
  problems    Problem[]
  tickets     Ticket[]
  slaPolicies SLAPolicy[]

  @@map("categories")
}

model Problem {
  id             String   @id @default(cuid())
  statement      String
  symptoms       String
  impact         String?
  productId      String
  categoryId     String?
  severity       String
  customerImpact String?
  businessImpact String?
  environment    String?
  createdAt      DateTime @default(now())

  product  Product   @relation(fields: [productId], references: [id])
  category Category? @relation(fields: [categoryId], references: [id])
  tickets  Ticket[]

  investigations Investigation[]
  rootCauses     RootCause[]
  solutions      Solution[]

  @@map("problems")
}

model Ticket {
  id               String   @id @default(cuid())
  code             String   @unique // <PRODUCT_CODE>-<YEAR>-<SEQUENCE> — see
  // specs/003-ticketing/research.md "Ticket code format"
  productId        String
  problemId        String
  customerId       String
  externalUserId   String // denormalized copy of CustomerReference's field, for query
  externalTenantId String // convenience without a join — see data-model.md
  status           String   @default("NEW") // one of the 12 lifecycle states — see
  // specs/003-ticketing/research.md "Ticket lifecycle state machine"
  priority         String
  severity         String
  categoryId       String?
  idempotencyKey   String?
  version          Int      @default(1) // optimistic concurrency — see research.md
  createdAt        DateTime @default(now())
  updatedAt        DateTime @updatedAt

  product           Product             @relation(fields: [productId], references: [id])
  problem           Problem             @relation(fields: [problemId], references: [id])
  customer          CustomerReference   @relation(fields: [customerId], references: [id])
  category          Category?           @relation(fields: [categoryId], references: [id])
  messages          TicketMessage[]
  attachments       TicketAttachment[]
  aiSessions        AISupportSession[]
  assignments       Assignment[]
  assignmentHistory AssignmentHistory[]
  slaRun            SLARun?
  escalationEvents  EscalationEvent[]
  resolution        Resolution?

  @@unique([productId, idempotencyKey])
  @@index([productId, status])
  @@index([externalTenantId, externalUserId])
  @@map("tickets")
}

model TicketMessage {
  id                String   @id @default(cuid())
  ticketId          String
  type              String // CUSTOMER_MESSAGE | AI_MESSAGE | AGENT_MESSAGE | INTERNAL_NOTE |
  // SYSTEM_EVENT | INVESTIGATION_NOTE | SOLUTION_NOTE
  authorRef         String // agentId, "ai", "system", or externalUserId — never a local FK
  body              String
  visibleToCustomer Boolean // set from the type->visibility map at write time — see
  // specs/003-ticketing/research.md "Message type -> visibility mapping"
  createdAt         DateTime @default(now())

  ticket Ticket @relation(fields: [ticketId], references: [id])

  @@index([ticketId, visibleToCustomer, createdAt])
  @@map("ticket_messages")
}

model TicketAttachment {
  id         String   @id @default(cuid())
  ticketId   String
  storageKey String // S3/MinIO object key — never the file itself
  fileName   String
  mimeType   String
  sizeBytes  Int
  scanStatus String   @default("pending") // pending | clean | infected | rejected
  uploadedBy String // agentId or externalUserId — same non-FK convention as authorRef
  createdAt  DateTime @default(now())

  ticket Ticket @relation(fields: [ticketId], references: [id])

  @@map("ticket_attachments")
}

model KnowledgeEntry {
  id                  String    @id @default(cuid())
  code                String // KB-<PRODUCT>-<SEQ>, e.g. KB-DQ-102 — shared across versions,
  // logical identifier is (code, version), NOT code alone — see
  // specs/004-product-knowledge/research.md "Versioning mechanism"
  version             Int       @default(1)
  isCurrentVersion    Boolean   @default(true)
  productId           String
  feature             String?
  type                String // known_issue | faq | resolution_procedure | operations
  problem             String?
  symptoms            String?
  errorCode           String?
  cause               String?
  recommendedSolution String?
  verificationSteps   String?
  escalationGuidance  String?
  status              String    @default("draft") // draft | published | unpublished
  effectiveDate       DateTime?
  categoryScope       String[]
  validationStatus    String    @default("unvalidated") // unvalidated | validated
  owner               String?
  lastReview          DateTime?
  source              String?
  createdAt           DateTime  @default(now())

  product Product @relation(fields: [productId], references: [id])

  @@unique([code, version])
  @@index([productId, isCurrentVersion, status, effectiveDate])
  @@map("knowledge_entries")
}

model ErrorCode {
  id          String @id @default(cuid())
  code        String // e.g. LAYOUT_PARSE_042
  productId   String
  description String

  product     Product      @relation(fields: [productId], references: [id])
  knownIssues KnownIssue[]

  @@unique([productId, code])
  @@map("error_codes")
}

model KnownIssue {
  id          String  @id @default(cuid())
  productId   String
  errorCodeId String?
  description String
  status      String  @default("open")

  product   Product    @relation(fields: [productId], references: [id])
  errorCode ErrorCode? @relation(fields: [errorCodeId], references: [id])

  @@map("known_issues")
}

model Runbook {
  id               String  @id @default(cuid())
  key              String // e.g. PDF_HTML_CONVERSION_FAILURE — shared across versions, logical
  // identifier is (key, productId, version), NOT key alone — same convention as KnowledgeEntry
  version          Int     @default(1)
  isCurrentVersion Boolean @default(true)
  productId        String
  steps            Json // ordered array — order preserved exactly as authored
  active           Boolean @default(true)

  product Product @relation(fields: [productId], references: [id])

  @@unique([key, productId, version])
  @@index([productId, key, isCurrentVersion, active])
  @@map("runbooks")
}

model AuditLog {
  id         String   @id @default(cuid())
  actor      String // ProductIntegration id, agent id, "system", "ai", etc. — never a local
  // User foreign key; see specs/002-saas-integration/research.md "Aligning AuditLog"
  actorType  String // customer | agent | admin | system | ai
  action     String
  entityType String
  entityId   String
  oldValue   Json?
  newValue   Json?
  reason     String?
  metadata   Json?
  createdAt  DateTime @default(now())

  @@map("audit_logs")
}

model AISupportSession {
  id                       String    @id @default(cuid())
  ticketId                 String
  ticket                   Ticket    @relation(fields: [ticketId], references: [id])
  status                   String // analyzing | troubleshooting | verifying | resolved | escalated |
  // ended_by_agent — mirrored onto Ticket.status through the existing 003 state machine, see
  // specs/005-ai-support/research.md "AISupportSession.status drives Ticket.status"
  activeRunbookKey         String?
  currentStepIndex         Int?
  clarifyingQuestionsAsked Int       @default(0)
  toolCallCount            Int       @default(0)
  startedAt                DateTime  @default(now())
  endedAt                  DateTime?

  diagnoses     AIDiagnosis[]
  interactions  AIInteraction[]
  actions       AIAction[]
  knowledgeRefs AIKnowledgeReference[]

  @@index([ticketId, status])
  @@map("ai_support_sessions")
}

model AIDiagnosis {
  id             String           @id @default(cuid())
  sessionId      String
  session        AISupportSession @relation(fields: [sessionId], references: [id])
  product        String
  feature        String?
  problemType    String
  severity       String
  confidence     Float
  possibleCauses String[]
  createdAt      DateTime         @default(now())

  @@index([sessionId])
  @@map("ai_diagnoses")
}

model AIInteraction {
  id        String           @id @default(cuid())
  sessionId String
  session   AISupportSession @relation(fields: [sessionId], references: [id])
  role      String // customer | ai
  content   String
  createdAt DateTime         @default(now())

  @@index([sessionId, createdAt])
  @@map("ai_interactions")
}

model AIAction {
  id                String           @id @default(cuid())
  sessionId         String
  session           AISupportSession @relation(fields: [sessionId], references: [id])
  toolName          String
  input             Json
  riskLevel         String // low | medium | high — copied from the registry at evaluation time
  evaluationOutcome String // approved | pending_approval | refused
  refusalReason     String?
  approvedBy        String? // system-policy | agentId | null while pending_approval
  createdAt         DateTime         @default(now())

  result AIActionResult?

  @@index([sessionId, createdAt])
  @@map("ai_actions")
}

model AIActionResult {
  id        String   @id @default(cuid())
  actionId  String   @unique
  action    AIAction @relation(fields: [actionId], references: [id])
  output    Json
  status    String // success | failed
  createdAt DateTime @default(now())

  @@map("ai_action_results")
}

model AIKnowledgeReference {
  id             String           @id @default(cuid())
  sessionId      String
  session        AISupportSession @relation(fields: [sessionId], references: [id])
  knowledgeId    String // KnowledgeEntry.id — resolved through ai-support/knowledge's public
  // index.ts, not a cross-module DB-level FK (Constitution Principle III)
  relevanceScore Float?
  createdAt      DateTime         @default(now())

  @@index([sessionId])
  @@map("ai_knowledge_references")
}

model AIConfidencePolicy {
  id                     String   @id @default(cuid())
  productId              String? // null = system-wide default row
  product                Product? @relation(fields: [productId], references: [id])
  categoryId             String? // null = applies to every category of productId
  highThreshold          Float
  lowThreshold           Float
  maxClarifyingQuestions Int
  updatedAt              DateTime @updatedAt

  @@unique([productId, categoryId])
  @@map("ai_confidence_policies")
}

model Team {
  id        String   @id @default(cuid())
  name      String
  active    Boolean  @default(true)
  createdAt DateTime @default(now())
  updatedAt DateTime @updatedAt

  agents         Agent[]
  hierarchyNodes HierarchyNode[]

  @@map("teams")
}

model Agent {
  id        String   @id @default(cuid())
  teamId    String
  team      Team     @relation(fields: [teamId], references: [id])
  name      String
  active    Boolean  @default(true)
  createdAt DateTime @default(now())
  updatedAt DateTime @updatedAt

  // Nullable link to the login identity this routing/skills profile belongs to — schema
  // capability only, no workflow sets it yet; see specs/010-identity-auth/research.md.
  userId String? @unique
  user   User?   @relation(fields: [userId], references: [id])

  skills       AgentSkill[]
  availability AgentAvailability?
  assignments  Assignment[]

  @@index([teamId, active])
  @@map("agents")
}

model AgentSkill {
  id       String @id @default(cuid())
  agentId  String
  agent    Agent  @relation(fields: [agentId], references: [id])
  skillTag String
  level    Int // proficiency, used by a future SKILL_BASED assignment strategy — not
  // interpreted by this feature

  @@unique([agentId, skillTag])
  @@map("agent_skills")
}

model AgentAvailability {
  id           String   @id @default(cuid())
  agentId      String   @unique
  agent        Agent    @relation(fields: [agentId], references: [id])
  status       String // available | busy | away | offline — validated at the schema layer
  workingHours Json // per business calendar — opaque to this feature
  currentLoad  Int      @default(0)
  updatedAt    DateTime @updatedAt

  // Last-write-wins on purpose — see specs/006-support-organization/research.md "Availability
  // concurrency"; no expectedVersion field here, unlike Ticket.status/KnowledgeEntry.version.

  @@map("agent_availability")
}

model HierarchyNode {
  id       String          @id @default(cuid())
  name     String
  parentId String?
  parent   HierarchyNode?  @relation("HierarchyTree", fields: [parentId], references: [id])
  children HierarchyNode[] @relation("HierarchyTree")
  order    Int
  teamId   String?
  team     Team?           @relation(fields: [teamId], references: [id])

  skills             String[]
  productScope       String[] // external product ids; empty = matches every product
  categoryScope      String[] // free text; empty = matches every category
  priorityScope      String[] // free text; empty = matches every priority
  assignmentStrategy String // free-text reference — no real strategy table exists yet (Phase 7)
  slaPolicyId        String? // free-text reference — no SlaPolicy table exists yet (Phase 8)
  escalationPolicyId String? // free-text reference — no EscalationPolicy table exists yet
  entryConditions    Json? // opaque rule expression — stored, not evaluated, by this feature
  exitConditions     Json? // opaque rule expression — stored, not evaluated, by this feature
  active             Boolean  @default(true)
  createdAt          DateTime @default(now())
  updatedAt          DateTime @updatedAt

  escalationRules EscalationRule[]

  @@index([parentId, order])
  @@index([active])
  @@map("hierarchy_nodes")
}

model Assignment {
  id       String  @id @default(cuid())
  ticketId String // not unique — one row per assignment period, see
  // specs/007-orchestration-assignment/research.md
  ticket   Ticket  @relation(fields: [ticketId], references: [id])
  agentId  String
  agent    Agent   @relation(fields: [agentId], references: [id])
  strategy String // ROUND_ROBIN | LEAST_LOADED | SKILL_BASED | MANUAL | DIRECT
  reason   String?

  isCurrent    Boolean   @default(true)
  assignedAt   DateTime  @default(now())
  unassignedAt DateTime?

  @@index([ticketId, isCurrent])
  @@index([agentId, isCurrent])
  @@map("assignments")
}

model AssignmentHistory {
  id        String   @id @default(cuid())
  ticketId  String
  ticket    Ticket   @relation(fields: [ticketId], references: [id])
  agentId   String? // null for a "no eligible agent" outcome — FR-008
  action    String // assigned | reassigned | unassigned
  strategy  String
  reason    String?
  actor     String // system | agentId | adminId
  createdAt DateTime @default(now())

  @@index([ticketId, createdAt])
  @@map("assignment_history")
}

model SLAPolicy {
  id            String    @id @default(cuid())
  name          String
  productId     String? // wildcard when null — see data-model.md "Resolution"
  product       Product?  @relation(fields: [productId], references: [id])
  categoryId    String?
  category      Category? @relation(fields: [categoryId], references: [id])
  problemTypeId String? // free-text — no ProblemType table exists in this codebase
  priority      String? // free-text, matches Ticket.priority

  firstResponseMinutes    Int
  investigationMinutes    Int? // stored per doc06; not read by this feature (spec.md Assumptions)
  resolutionMinutes       Int
  customerResponseMinutes Int? // stored per doc06; not read by this feature (spec.md Assumptions)

  businessCalendarId String? // null = 24/7, no exclusions — an explicit policy choice
  businessCalendar   BusinessCalendar? @relation(fields: [businessCalendarId], references: [id])

  active    Boolean  @default(true)
  createdAt DateTime @default(now())
  updatedAt DateTime @updatedAt

  slaRuns SLARun[]

  @@index([productId, categoryId, active])
  @@map("sla_policies")
}

model SLARun {
  id       String    @id @default(cuid())
  ticketId String    @unique // one run per ticket — no reopen-cycle support (spec.md Assumptions)
  ticket   Ticket    @relation(fields: [ticketId], references: [id])
  policyId String
  policy   SLAPolicy @relation(fields: [policyId], references: [id])

  firstResponseDueAt DateTime?
  resolutionDueAt    DateTime?
  status             String // running | paused | warning | breached | completed

  pausedAt  DateTime?
  resumedAt DateTime?

  breachedAt              DateTime?
  // Additive refinement beyond doc06 (research.md/data-model.md): records a first-response
  // breach separately from the resolution-timer breach status above, and doubles as the
  // idempotency guard for the breach-detection sweep (never re-fires on the same run).
  firstResponseBreachedAt DateTime?

  completedAt DateTime?

  @@index([status, resolutionDueAt])
  @@index([status, firstResponseDueAt])
  @@map("sla_runs")
}

model BusinessCalendar {
  id           String @id @default(cuid())
  name         String
  timezone     String // IANA zone name, e.g. "America/New_York"
  workingHours Json // { mon?: {start,end}, tue?: ..., ... } — see research.md

  holidays Holiday[]
  policies SLAPolicy[]

  @@map("business_calendars")
}

model Holiday {
  id          String           @id @default(cuid())
  calendarId  String
  calendar    BusinessCalendar @relation(fields: [calendarId], references: [id], onDelete: Cascade)
  date        DateTime // compared by calendar date only, in the calendar's own timezone
  description String?

  @@index([calendarId, date])
  @@map("holidays")
}

model EscalationPolicy {
  id        String   @id @default(cuid())
  name      String
  productId String? // wildcard (global) when null — see research.md "Escalation policy resolution"
  product   Product? @relation(fields: [productId], references: [id])
  active    Boolean  @default(true)

  rules EscalationRule[]

  @@index([productId, active])
  @@map("escalation_policies")
}

model EscalationRule {
  id       String           @id @default(cuid())
  policyId String
  policy   EscalationPolicy @relation(fields: [policyId], references: [id])

  triggerType String // one of doc05 §6's 10 values; only resolution_breach/first_response_breach
  // are ever evaluated by this feature — the other 8 are valid, stored, inert config
  // (research.md)
  condition   Json // stored, not evaluated, by this feature (research.md)

  targetNodeId String
  targetNode   HierarchyNode @relation(fields: [targetNodeId], references: [id])

  notify Json // who/how to notify — stored and returned only, no delivery mechanism exists
  active Boolean @default(true)

  @@index([policyId, triggerType, active])
  @@map("escalation_rules")
}

model EscalationEvent {
  id       String @id @default(cuid())
  ticketId String
  ticket   Ticket @relation(fields: [ticketId], references: [id])

  ruleId     String? // null for a manual escalation or a breach with no matching rule
  fromNodeId String?
  toNodeId   String?

  reason      String
  triggeredBy String // system | <agentId> | <adminId>
  createdAt   DateTime @default(now())

  @@index([ticketId, createdAt])
  @@map("escalation_events")
}

model Investigation {
  id            String   @id @default(cuid())
  problemId     String
  problem       Problem  @relation(fields: [problemId], references: [id])
  investigator  String
  findings      Json
  evidence      Json?
  internalNotes String? // never exposed on a customer-facing read — see
  // specs/009-problem-resolution/spec.md FR-003
  status        String   @default("open") // open | complete
  createdAt     DateTime @default(now())

  @@index([problemId, createdAt])
  @@map("investigations")
}

model RootCause {
  id          String   @id @default(cuid())
  problemId   String
  problem     Problem  @relation(fields: [problemId], references: [id])
  type        String // technical | configuration | external_dependency | business |
  // contributing_factor
  description String
  createdAt   DateTime @default(now())

  @@index([problemId, createdAt])
  @@map("root_causes")
}

model Solution {
  id        String   @id @default(cuid())
  problemId String
  problem   Problem  @relation(fields: [problemId], references: [id])
  proposed  String
  approved  Boolean  @default(false)
  createdAt DateTime @default(now())

  implementation SolutionImplementation?
  verification   SolutionVerification?

  @@index([problemId, createdAt])
  @@map("solutions")
}

model SolutionImplementation {
  id            String   @id @default(cuid())
  solutionId    String   @unique
  solution      Solution @relation(fields: [solutionId], references: [id])
  notes         String?
  implementedBy String
  implementedAt DateTime @default(now())

  @@map("solution_implementations")
}

model SolutionVerification {
  id         String   @id @default(cuid())
  solutionId String   @unique
  solution   Solution @relation(fields: [solutionId], references: [id])
  method     String // automated | technical_test | customer_confirmation | agent_confirmation
  result     String // success | failed
  evidence   Json?
  verifiedAt DateTime @default(now())

  @@map("solution_verifications")
}

model Resolution {
  id         String   @id @default(cuid())
  ticketId   String   @unique
  ticket     Ticket   @relation(fields: [ticketId], references: [id])
  outcome    String
  resolvedBy String // "ai" | agentId — see specs/009-problem-resolution/data-model.md
  resolvedAt DateTime @default(now())

  @@map("resolutions")
}