/**
 * U-001: Stage Transition — Legal Transition
 * U-002: Stage Transition — Illegal Transition
 */

import { describe, it, expect, beforeAll, afterAll } from 'vitest'
import { prisma } from '../setup'
import {
  createTestUser,
  createTestProgram,
  createTestPipeline,
  createTestTrack,
  createTestStage,
  createTestTransition,
  createTestProject,
  createTestPSS,
  cleanupTestData,
} from '../helpers'
import { validateTransition, executeTransition } from '@/server/services/stage-engine'

let programId: string
let userIds: string[] = []

beforeAll(async () => {
  const program = await createTestProgram({ name: 'StageEngine Test' })
  programId = program.id
})

afterAll(async () => {
  await cleanupTestData(programId, userIds)
})

describe('U-001: Legal Transition', () => {
  it('validates and executes a legal transition between two stages', async () => {
    const admin = await createTestUser('SUPER_ADMIN')
    userIds.push(admin.id)

    const pipeline = await createTestPipeline(programId)
    const track = await createTestTrack(pipeline.id)
    const stageA = await createTestStage(track.id, {
      name: 'Stage A',
      stageType: 'FILTER',
      status: 'STAGE_ACTIVE',
      sortOrder: 0,
    })
    const stageB = await createTestStage(track.id, {
      name: 'Stage B',
      stageType: 'EVALUATION',
      status: 'STAGE_ACTIVE',
      sortOrder: 1,
    })

    // Create a legal transition path A → B
    await createTestTransition(stageA.id, stageB.id)

    // Create project with PSS in stage A
    const project = await createTestProject(programId)
    await createTestPSS(project.id, track.id, stageA.id, { state: 'PENDING' })

    // Validate
    const validation = await validateTransition(project.id, stageA.id, stageB.id, prisma)
    expect(validation.valid).toBe(true)
    expect(validation.errors).toHaveLength(0)

    // Execute
    const result = await executeTransition(
      project.id, track.id, stageA.id, stageB.id, 'PENDING', admin.id, prisma
    )
    expect(result.success).toBe(true)
    expect(result.projectStageState).not.toBeNull()
    expect(result.projectStageState!.stageId).toBe(stageB.id)
    expect(result.projectStageState!.state).toBe('PENDING')

    // Verify source PSS was exited
    const sourcePSS = await prisma.projectStageState.findFirst({
      where: { projectId: project.id, stageId: stageA.id },
    })
    expect(sourcePSS!.exitedAt).not.toBeNull()

    // Verify dest PSS was created
    const destPSS = await prisma.projectStageState.findFirst({
      where: { projectId: project.id, stageId: stageB.id, exitedAt: null },
    })
    expect(destPSS).not.toBeNull()
    expect(destPSS!.state).toBe('PENDING')

    // Verify audit log entry was created
    const auditLog = await prisma.decisionAuditLog.findFirst({
      where: {
        entityType: 'ProjectStageState',
        eventType: 'stage.transitioned',
        entityId: destPSS!.id,
      },
    })
    expect(auditLog).not.toBeNull()
    expect(auditLog!.actorId).toBe(admin.id)
  })
})

describe('U-002: Illegal Transition', () => {
  it('rejects transition when no StageTransition record exists', async () => {
    const pipeline = await createTestPipeline(programId)
    const track = await createTestTrack(pipeline.id)
    const stageA = await createTestStage(track.id, {
      name: 'Stage A (no path)',
      stageType: 'FILTER',
      status: 'STAGE_ACTIVE',
      sortOrder: 0,
    })
    const stageB = await createTestStage(track.id, {
      name: 'Stage B (no path)',
      stageType: 'EVALUATION',
      status: 'STAGE_ACTIVE',
      sortOrder: 1,
    })

    // No StageTransition created between A and B

    const project = await createTestProject(programId)
    await createTestPSS(project.id, track.id, stageA.id, { state: 'PENDING' })

    const validation = await validateTransition(project.id, stageA.id, stageB.id, prisma)
    expect(validation.valid).toBe(false)
    expect(validation.errors.length).toBeGreaterThan(0)
    expect(validation.errors.some(e => e.includes('No transition defined'))).toBe(true)
  })

  it('rejects transition when destination stage is archived', async () => {
    const pipeline = await createTestPipeline(programId)
    const track = await createTestTrack(pipeline.id)
    const stageA = await createTestStage(track.id, {
      name: 'Active Stage',
      status: 'STAGE_ACTIVE',
      sortOrder: 0,
    })
    const stageB = await createTestStage(track.id, {
      name: 'Archived Stage',
      status: 'STAGE_ARCHIVED',
      sortOrder: 1,
    })

    await createTestTransition(stageA.id, stageB.id)

    const project = await createTestProject(programId)
    await createTestPSS(project.id, track.id, stageA.id, { state: 'PENDING' })

    const validation = await validateTransition(project.id, stageA.id, stageB.id, prisma)
    expect(validation.valid).toBe(false)
    expect(validation.errors.some(e => e.includes('archived'))).toBe(true)
  })

  it('rejects transition when project has no active PSS in source stage', async () => {
    const pipeline = await createTestPipeline(programId)
    const track = await createTestTrack(pipeline.id)
    const stageA = await createTestStage(track.id, {
      name: 'Source',
      status: 'STAGE_ACTIVE',
      sortOrder: 0,
    })
    const stageB = await createTestStage(track.id, {
      name: 'Dest',
      status: 'STAGE_ACTIVE',
      sortOrder: 1,
    })

    await createTestTransition(stageA.id, stageB.id)

    const project = await createTestProject(programId)
    // No PSS created for this project

    const validation = await validateTransition(project.id, stageA.id, stageB.id, prisma)
    expect(validation.valid).toBe(false)
    expect(validation.errors.some(e => e.includes('no active state'))).toBe(true)
  })
})