import { describe, it, expect } from 'vitest'
import { readFileSync, existsSync, readdirSync } from 'node:fs'
import { join } from 'node:path'
import {
  computeObjectPhaseOffsetMs,
  updateAnimatedObject,
  updateAnimatedObjects,
  PERSISTENT_ILLUMINATION_TOKENS,
  type ObjectDrawable,
  type AnimatedObjectFrame,
} from '../src/scene/act-scene.ts'
import {
  updateAnimatableTiles,
  type AnimatableTile,
  DEFAULT_ANIMATED_TILE_FRAME_DURATION_MS,
} from '../src/game/animated-tiles.ts'

describe('Dungeon & Wilderness Illumination & Animated Tile Sequences (Issue #398)', () => {
  describe('PERSISTENT_ILLUMINATION_TOKENS definitions', () => {
    it('includes all canonical illumination and environmental fire tokens', () => {
      const requiredTokens = ['TO', 'A1', 'A2', '3O', '3o', 'FX', 'FY', 'FZ', 'BR', 'BF', 'FL']
      for (const token of requiredTokens) {
        expect(PERSISTENT_ILLUMINATION_TOKENS.has(token)).toBe(true)
      }
    })
  })

  describe('Persistent illumination looping parity (updateAnimatedObject)', () => {
    const dummyAtlasFrame = (i: number) => ({
      x: i * 32,
      y: 0,
      width: 32,
      height: 64,
    })

    const createTestIlluminationDrawable = (
      token: string,
      frameCount = 10,
      frameDurationMs = 80,
      forceCycleAnim?: boolean,
    ): ObjectDrawable => {
      const frames: AnimatedObjectFrame[] = Array.from({ length: frameCount }, (_, i) => ({
        frame: dummyAtlasFrame(i),
        page: 0,
        offsetX: -16,
        offsetY: -32,
      }))

      return {
        token,
        frame: frames[0]!.frame,
        x: 100,
        y: 200,
        depth: 60,
        page: 0,
        baseX: 100,
        baseY: 200,
        animatedFrames: frames,
        frameDurationMs,
        cycleAnim: forceCycleAnim,
        phaseOffsetMs: 0,
        currentFrameIndex: 0,
      }
    }

    it('cycles continuously even if cycleAnim was false for persistent illumination tokens', () => {
      // Tokens like FX, FY, FZ (environmental fires) or BR (braziers) might have cycleAnim=0 in Objects.txt mode 0
      const tokensToTest = ['TO', 'A1', 'A2', '3O', '3o', 'FX', 'FY', 'FZ', 'BR', 'BF', 'FL']

      for (const token of tokensToTest) {
        const obj = createTestIlluminationDrawable(token, 10, 80, false)
        const totalDuration = 10 * 80 // 800ms

        // At t=0
        updateAnimatedObject(obj, 0)
        expect(obj.currentFrameIndex).toBe(0)

        // At t=160ms (frame 2)
        updateAnimatedObject(obj, 160)
        expect(obj.currentFrameIndex).toBe(2)

        // Beyond cycle: at t=800ms, should loop back to frame 0 (NOT clamped to frame 9)
        updateAnimatedObject(obj, 800)
        expect(obj.currentFrameIndex).toBe(0)

        // At t=1040ms (800 + 3 * 80), should be frame 3
        updateAnimatedObject(obj, 1040)
        expect(obj.currentFrameIndex).toBe(3)
      }
    })

    it('clamps non-persistent objects when cycleAnim is false', () => {
      const nonFireObj = createTestIlluminationDrawable('XX', 10, 80, false)
      // At t=1000ms (> 800ms total duration)
      updateAnimatedObject(nonFireObj, 1000)
      expect(nonFireObj.currentFrameIndex).toBe(9) // clamped to last frame
    })

    it('maintains independent spatial phase offsets across torches and candles', () => {
      const duration = 20 * 51.2
      const p1 = computeObjectPhaseOffsetMs(100, 200, duration)
      const p2 = computeObjectPhaseOffsetMs(104, 208, duration)
      expect(p1).not.toBe(p2)
      expect(p1).toBeGreaterThanOrEqual(0)
      expect(p1).toBeLessThan(duration)
    })

    it('prevents sprite coordinate drift across frame transitions and loops', () => {
      const frames: AnimatedObjectFrame[] = [
        { frame: dummyAtlasFrame(0), page: 0, offsetX: -10, offsetY: -20 },
        { frame: dummyAtlasFrame(1), page: 0, offsetX: -15, offsetY: -25 },
        { frame: dummyAtlasFrame(2), page: 0, offsetX: -8, offsetY: -18 },
      ]
      const obj: ObjectDrawable = {
        token: 'TO',
        frame: frames[0]!.frame,
        x: 100 + frames[0]!.offsetX,
        y: 200 + frames[0]!.offsetY,
        depth: 60,
        page: 0,
        baseX: 100,
        baseY: 200,
        animatedFrames: frames,
        frameDurationMs: 100,
        cycleAnim: true,
        currentFrameIndex: 0,
      }

      for (let clock = 0; clock <= 3000; clock += 50) {
        updateAnimatedObject(obj, clock)
        const expectedFrameIdx = Math.floor(clock / 100) % 3
        expect(obj.currentFrameIndex).toBe(expectedFrameIdx)
        const expectedFrame = frames[expectedFrameIdx]!
        expect(obj.x).toBe(100 + expectedFrame.offsetX)
        expect(obj.y).toBe(200 + expectedFrame.offsetY)
      }
    })

    it('safely handles degenerate frame inputs (empty, single frame, zero/negative duration)', () => {
      const singleFrameObj: ObjectDrawable = {
        token: 'TO',
        frame: dummyAtlasFrame(0),
        x: 100,
        y: 200,
        depth: 60,
        page: 0,
        baseX: 100,
        baseY: 200,
        animatedFrames: [{ frame: dummyAtlasFrame(0), page: 0, offsetX: 0, offsetY: 0 }],
        frameDurationMs: 80,
        currentFrameIndex: 0,
      }
      expect(updateAnimatedObject(singleFrameObj, 1000)).toBe(false)
      expect(singleFrameObj.currentFrameIndex).toBe(0)

      const zeroDurationObj = createTestIlluminationDrawable('TO', 5, 0, true)
      expect(updateAnimatedObject(zeroDurationObj, 120)).toBe(true)
      expect(zeroDurationObj.currentFrameIndex).toBe(3)

      const negClockObj = createTestIlluminationDrawable('TO', 5, 40, true)
      expect(updateAnimatedObject(negClockObj, -100)).toBe(false)
      expect(negClockObj.currentFrameIndex).toBe(0)
    })
  })

  describe('DT1 animated tile serialization and unpacking parity', () => {
    it('correctly unpacks extended animated tile rows [frameIndex, x, y, cx, cy, ...animFrames]', () => {
      // Simulate scene frames
      const dummyFrames = [
        { x: 0, y: 0, width: 160, height: 80 },
        { x: 160, y: 0, width: 160, height: 80 },
        { x: 320, y: 0, width: 160, height: 80 },
        { x: 480, y: 0, width: 160, height: 80 },
      ]
      const framePlacement = [
        [0, 0, 0, 160, 80],
        [0, 160, 0, 160, 80],
        [0, 320, 0, 160, 80],
        [0, 480, 0, 160, 80],
      ]

      // Row with 4 animated frames: indices 0, 1, 2, 3
      const row = [0, 100, 200, 5, 10, 0, 1, 2, 3]
      const frameIndex = row[0] ?? 0
      const animFrames = row.length > 5 ? row.slice(5) : undefined
      const anim = animFrames && animFrames.length > 1
        ? animFrames.map(fIdx => ({
            frame: dummyFrames[fIdx]!,
            page: framePlacement[fIdx]?.[0] ?? 0,
          }))
        : undefined

      const tile: AnimatableTile = {
        frame: dummyFrames[frameIndex]!,
        page: framePlacement[frameIndex]?.[0] ?? 0,
        animatedFrames: anim,
        currentFrameIndex: 0,
      }

      expect(tile.animatedFrames).toBeDefined()
      expect(tile.animatedFrames!.length).toBe(4)

      // Verify updateAnimatableTiles advances frames
      const tiles = [tile]
      // At t=0ms
      updateAnimatableTiles(tiles, 0, 'time', DEFAULT_ANIMATED_TILE_FRAME_DURATION_MS)
      expect(tile.currentFrameIndex).toBe(0)

      // At t=150ms (> 128ms)
      updateAnimatableTiles(tiles, 150, 'time', DEFAULT_ANIMATED_TILE_FRAME_DURATION_MS)
      expect(tile.currentFrameIndex).toBe(1)
      expect(tile.frame).toEqual(dummyFrames[1])

      // At t=550ms (> 4 * 128 = 512ms, looped to frame 0)
      updateAnimatableTiles(tiles, 550, 'time', DEFAULT_ANIMATED_TILE_FRAME_DURATION_MS)
      expect(tile.currentFrameIndex).toBe(0)
      expect(tile.frame).toEqual(dummyFrames[0])
    })
  })

  describe('Baked Map Scene Inspection (Wilderness & Dungeons)', () => {
    const packsDir = join(process.cwd(), 'samples/d2-packs')

    it('verifies town scene (towne1) preserves all animated objects', () => {
      const townPath = join(packsDir, 'act1/1-act-1-town-towne1/scene.json')
      expect(existsSync(townPath)).toBe(true)

      const scene = JSON.parse(readFileSync(townPath, 'utf8'))
      const objects = scene.objects as any[]

      // Campfire (RB)
      const rbs = objects.filter(o => o.token === 'RB')
      expect(rbs.length).toBeGreaterThan(0)
      for (const rb of rbs) {
        expect(rb.animatedFrames?.length).toBe(20)
        expect(rb.cycleAnim).toBe(true)
      }

      // Torches (TO)
      const tos = objects.filter(o => o.token === 'TO')
      expect(tos.length).toBeGreaterThan(0)
      for (const to of tos) {
        expect(to.animatedFrames?.length).toBe(20)
        expect(to.cycleAnim).toBe(true)
      }
    })

    it('verifies Cave (Level 10) packs have animated illumination objects', () => {
      const act1Dir = join(packsDir, 'act1')
      expect(existsSync(act1Dir)).toBe(true)

      const caveDirs = readdirSync(act1Dir).filter(name => name.startsWith('10-act-1-cave'))
      expect(caveDirs.length).toBeGreaterThan(0)
      for (const d of caveDirs) {
        const scenePath = join(act1Dir, d, 'scene.json')
        expect(existsSync(scenePath)).toBe(true)
        const scene = JSON.parse(readFileSync(scenePath, 'utf8'))
        const illumination = (scene.objects as any[]).filter(o =>
          o.token && PERSISTENT_ILLUMINATION_TOKENS.has(o.token.trim().toUpperCase())
        )
        expect(illumination.length).toBeGreaterThan(0)
        for (const item of illumination) {
          if (item.animatedFrames) {
            expect(item.animatedFrames.length).toBeGreaterThan(1)
            expect(item.cycleAnim).toBe(true)
            expect(item.frameDelta).toBeGreaterThan(0)
          }
        }
      }
    })

    it('verifies Catacombs (Level 34) packs have animated candles (A1, A2) and fires (BF, BR)', () => {
      const act1Dir = join(packsDir, 'act1')
      expect(existsSync(act1Dir)).toBe(true)

      const catacombsDirs = readdirSync(act1Dir).filter(name => name.startsWith('34-act-1-catacombs'))
      expect(catacombsDirs.length).toBeGreaterThan(0)

      let totalCandlesOrFires = 0
      for (const d of catacombsDirs) {
        const scenePath = join(act1Dir, d, 'scene.json')
        expect(existsSync(scenePath)).toBe(true)
        const scene = JSON.parse(readFileSync(scenePath, 'utf8'))
        const items = (scene.objects as any[]).filter(o =>
          o.token && ['A1', 'A2', 'BF', 'BR', 'TO'].includes(o.token.trim().toUpperCase())
        )
        for (const item of items) {
          totalCandlesOrFires += 1
          if (item.animatedFrames) {
            expect(item.animatedFrames.length).toBeGreaterThan(1)
            expect(item.cycleAnim).toBe(true)
            expect(item.frameDurationMs).toBeGreaterThan(0)
          }
        }
      }
      expect(totalCandlesOrFires).toBeGreaterThan(0)
    })

    it('verifies Wilderness and Crypt maps contain cycleAnim=true on illumination objects', () => {
      const act1Dir = join(packsDir, 'act1')
      expect(existsSync(act1Dir)).toBe(true)

      const cryptDirs = readdirSync(act1Dir).filter(name => name.startsWith('18-act-1-crypt') || name.startsWith('19-act-1-crypt'))
      expect(cryptDirs.length).toBeGreaterThan(0)
      for (const d of cryptDirs) {
        const scenePath = join(act1Dir, d, 'scene.json')
        expect(existsSync(scenePath)).toBe(true)
        const scene = JSON.parse(readFileSync(scenePath, 'utf8'))
        const items = (scene.objects as any[]).filter(o =>
          o.token && PERSISTENT_ILLUMINATION_TOKENS.has(o.token.trim().toUpperCase())
        )
        for (const item of items) {
          if (item.animatedFrames) {
            expect(item.cycleAnim).toBe(true)
          }
        }
      }
    })

    it('verifies DT1 animated tile sequences in scenes that contain animated tiles', () => {
      const act4Dir = join(packsDir, 'act4')
      expect(existsSync(act4Dir)).toBe(true)

      // River of flame (Level 107) and Chaos Sanctuary (Level 108) have animated lava tiles
      const chaosDirs = readdirSync(act4Dir).filter(name => name.startsWith('108-act-4-diablo') || name.startsWith('107-act-4-lava'))
      expect(chaosDirs.length).toBeGreaterThan(0)
      let totalAnimatedTiles = 0
      for (const d of chaosDirs) {
        const scenePath = join(act4Dir, d, 'scene.json')
        expect(existsSync(scenePath)).toBe(true)
        const scene = JSON.parse(readFileSync(scenePath, 'utf8'))
        const draws = [
          ...(scene.floors ?? []),
          ...(scene.walls ?? []),
          ...(scene.shadows ?? []),
          ...(scene.roofs ?? []),
        ]
        const animatedTileDraws = draws.filter((row: number[]) => row.length > 5)
        totalAnimatedTiles += animatedTileDraws.length
        if (animatedTileDraws.length > 0) {
          for (const row of animatedTileDraws) {
            const animFrames = row.slice(5)
            expect(animFrames.length).toBeGreaterThan(1)
            // Each frame index should be valid in scene.frames
            for (const fIdx of animFrames) {
              expect(fIdx).toBeGreaterThanOrEqual(0)
              expect(fIdx).toBeLessThan(scene.frames.length)
            }
          }
        }
      }
      expect(totalAnimatedTiles).toBeGreaterThan(0)
    })
  })
})