import { describe, expect, it } from 'vitest'
import fs from 'node:fs'
import path from 'node:path'
import zlib from 'node:zlib'
import {
  MISSILE_METAS,
  CORPSEEXPLOSION_META,
  POISONCORPSEEXPLOSION_META,
  POISONEXPLOSIONCLOUD_META,
  POISONPUFF_META,
  CURSECAST_META,
  BONECAST_META,
  BONESPEARTRAIL_META,
  REVIVE_META,
  REVIVESMALL_META,
  REVIVEMEDIUM_META,
  REVIVELARGE_META,
  BONESPEAREXPLODE_META,
  type MissileMeta,
} from '../../../src/client/render/missiles-meta.ts'
import {
  OVERLAY_METAS,
  CURSE_AMPLIFY_DAMAGE_OVERLAY_META,
  CURSE_DIM_VISION_OVERLAY_META,
  CURSE_WEAKEN_OVERLAY_META,
  CURSE_IRON_MAIDEN_OVERLAY_META,
  CURSE_TERROR_OVERLAY_META,
  CURSE_CONFUSE_OVERLAY_META,
  CURSE_LIFE_TAP_OVERLAY_META,
  CURSE_ATTRACT_OVERLAY_META,
  CURSE_DECREPIFY_OVERLAY_META,
  CURSE_LOWER_RESIST_OVERLAY_META,
  HIT_IRON_MAIDEN_OVERLAY_META,
  HIT_LIFE_TAP_OVERLAY_META,
  BONE_ARMOR_CAST_OVERLAY_META,
  BONE_ARMOR_FRONT_OVERLAY_META,
  BONE_ARMOR_BACK_OVERLAY_META,
  type OverlayMeta,
} from '../../../src/client/render/overlays-meta.ts'

// Strict PNG RGBA Decoder
function decodeRgbaPng(buf: Buffer) {
  const width = buf.readUInt32BE(16)
  const height = buf.readUInt32BE(20)
  const bitDepth = buf[24]!
  const colorType = buf[25]!

  const idatParts: Buffer[] = []
  let offset = 8
  while (offset < buf.length) {
    const len = buf.readUInt32BE(offset)
    const type = buf.subarray(offset + 4, offset + 8).toString('ascii')
    if (type === 'IDAT') {
      idatParts.push(buf.subarray(offset + 8, offset + 8 + len))
    }
    offset += 12 + len
  }
  const idat = Buffer.concat(idatParts)
  const raw = zlib.inflateSync(idat)

  const bpp = 4
  const rowBytes = width * bpp
  const pixels = new Uint8Array(width * height * 4)
  let srcAt = 0
  let dstAt = 0

  for (let y = 0; y < height; y++) {
    const filter = raw[srcAt++]
    const row = raw.subarray(srcAt, srcAt + rowBytes)
    srcAt += rowBytes

    const prevRow = y > 0 ? pixels.subarray((y - 1) * rowBytes, y * rowBytes) : null
    const curRow = pixels.subarray(dstAt, dstAt + rowBytes)

    for (let x = 0; x < rowBytes; x++) {
      const left = x >= bpp ? curRow[x - bpp]! : 0
      const up = prevRow ? prevRow[x]! : 0
      const upLeft = prevRow && x >= bpp ? prevRow[x - bpp]! : 0

      let val = row[x]!
      if (filter === 0) {
        // None
      } else if (filter === 1) {
        val = (val + left) & 0xff
      } else if (filter === 2) {
        val = (val + up) & 0xff
      } else if (filter === 3) {
        val = (val + Math.floor((left + up) / 2)) & 0xff
      } else if (filter === 4) {
        const p = left + up - upLeft
        const pa = Math.abs(p - left)
        const pb = Math.abs(p - up)
        const pc = Math.abs(p - upLeft)
        let pr = upLeft
        if (pa <= pb && pa <= pc) pr = left
        else if (pb <= pc) pr = up
        val = (val + pr) & 0xff
      }
      curRow[x] = val
    }
    dstAt += rowBytes
  }

  return { width, height, bitDepth, colorType, pixels }
}

describe('Challenger Adversarial Stress Suite — Necromancer Assets', () => {
  const publicMissilesDir = path.resolve(__dirname, '../../../public/missiles')
  const packMissilesDir = path.resolve(__dirname, '../../../samples/d2-packs/missiles')
  const publicOverlaysDir = path.resolve(__dirname, '../../../public/overlays')
  const packOverlaysDir = path.resolve(__dirname, '../../../samples/d2-packs/overlays')

  const TARGET_MISSILES = [
    { name: 'corpseexplosion', celFile: 'CorpseExplodeGuts', meta: CORPSEEXPLOSION_META },
    { name: 'poisoncorpseexplosion', celFile: 'CorpseExplodeGutsPoison', meta: POISONCORPSEEXPLOSION_META },
    { name: 'poisonexplosioncloud', celFile: 'PoisonSparks', meta: POISONEXPLOSIONCLOUD_META },
    { name: 'poisonpuff', celFile: 'PoisonSmokePuff', meta: POISONPUFF_META },
    { name: 'cursecast', celFile: 'CurseCast', meta: CURSECAST_META },
    { name: 'bonecast', celFile: 'BoneCast', meta: BONECAST_META },
    { name: 'bonespeartrail', celFile: 'BoneSpearTrail', meta: BONESPEARTRAIL_META },
    { name: 'revive', celFile: 'Revive', meta: REVIVE_META },
  ] as const

  const TARGET_OVERLAYS = [
    { name: 'curseamplifydamage', celFile: 'CurseAmplifyDamageEffect', meta: CURSE_AMPLIFY_DAMAGE_OVERLAY_META, preDraw: false },
    { name: 'cursedimvision', celFile: 'CurseDimVisionEffect', meta: CURSE_DIM_VISION_OVERLAY_META, preDraw: false },
    { name: 'curseweaken', celFile: 'CurseWeakenEffect', meta: CURSE_WEAKEN_OVERLAY_META, preDraw: false },
    { name: 'curseironmaiden', celFile: 'CurseIronMaidenEffect', meta: CURSE_IRON_MAIDEN_OVERLAY_META, preDraw: false },
    { name: 'curseterror', celFile: 'CurseTerrorEffect', meta: CURSE_TERROR_OVERLAY_META, preDraw: false },
    { name: 'curseconfuse', celFile: 'CurseConfuseEffect', meta: CURSE_CONFUSE_OVERLAY_META, preDraw: false },
    { name: 'cursereversevampire', celFile: 'CurseReverseVampireEffect', meta: CURSE_LIFE_TAP_OVERLAY_META, preDraw: false },
    { name: 'curseattract', celFile: 'CurseAttractHarmEffect', meta: CURSE_ATTRACT_OVERLAY_META, preDraw: false },
    { name: 'cursedecrepify', celFile: 'CurseDecrepifyEffect', meta: CURSE_DECREPIFY_OVERLAY_META, preDraw: false },
    { name: 'curselowerresist', celFile: 'CurseLowerResistEffect', meta: CURSE_LOWER_RESIST_OVERLAY_META, preDraw: false },
    { name: 'hit_ironmaiden', celFile: 'AuraThornsHit', meta: HIT_IRON_MAIDEN_OVERLAY_META, preDraw: false },
    { name: 'hit_reversevampire', celFile: 'CurseRevVampireHit', meta: HIT_LIFE_TAP_OVERLAY_META, preDraw: false },
    { name: 'bonearmor_cast', celFile: 'BoneShieldEmerge', meta: BONE_ARMOR_CAST_OVERLAY_META, preDraw: false },
    { name: 'bonearmor_front', celFile: 'BoneShieldFront', meta: BONE_ARMOR_FRONT_OVERLAY_META, preDraw: false },
    { name: 'bonearmor_back', celFile: 'BoneShieldBack', meta: BONE_ARMOR_BACK_OVERLAY_META, preDraw: true },
  ] as const

  describe('Adversarial Test 1: Transparent Border Thresholding & Halo Elimination on Pixel Buffers', () => {
    it('1.1 Asserts NO pixel in any Necromancer missile PNG has max(r,g,b) <= 4 with alpha > 0', () => {
      for (const m of TARGET_MISSILES) {
        const pngPath = path.join(publicMissilesDir, `${m.name}.png`)
        const buf = fs.readFileSync(pngPath)
        const { width, height, pixels } = decodeRgbaPng(buf)

        let haloCount = 0
        let haloSamples: { x: number; y: number; r: number; g: number; b: number; a: number }[] = []

        for (let y = 0; y < height; y++) {
          for (let x = 0; x < width; x++) {
            const idx = (y * width + x) * 4
            const r = pixels[idx]!
            const g = pixels[idx + 1]!
            const b = pixels[idx + 2]!
            const a = pixels[idx + 3]!
            const mVal = Math.max(r, g, b)

            if (mVal <= 4 && a > 0) {
              haloCount++
              if (haloSamples.length < 5) haloSamples.push({ x, y, r, g, b, a })
            }
          }
        }

        expect(
          haloCount,
          `Missile ${m.name}.png has ${haloCount} dark halo pixels (max(RGB)<=4 & alpha>0): ${JSON.stringify(haloSamples)}`
        ).toBe(0)
      }
    })

    it('1.2 Asserts NO pixel in any Necromancer overlay PNG has max(r,g,b) <= 4 with alpha > 0', () => {
      for (const o of TARGET_OVERLAYS) {
        const pngPath = path.join(publicOverlaysDir, `${o.name}.png`)
        const buf = fs.readFileSync(pngPath)
        const { width, height, pixels } = decodeRgbaPng(buf)

        let haloCount = 0
        let haloSamples: { x: number; y: number; r: number; g: number; b: number; a: number }[] = []

        for (let y = 0; y < height; y++) {
          for (let x = 0; x < width; x++) {
            const idx = (y * width + x) * 4
            const r = pixels[idx]!
            const g = pixels[idx + 1]!
            const b = pixels[idx + 2]!
            const a = pixels[idx + 3]!
            const mVal = Math.max(r, g, b)

            if (mVal <= 4 && a > 0) {
              haloCount++
              if (haloSamples.length < 5) haloSamples.push({ x, y, r, g, b, a })
            }
          }
        }

        expect(
          haloCount,
          `Overlay ${o.name}.png has ${haloCount} dark halo pixels (max(RGB)<=4 & alpha>0): ${JSON.stringify(haloSamples)}`
        ).toBe(0)
      }
    })

    it('1.3 Adversarial perimeter inspection: checks 1-pixel frame border and perimeter pixels around non-empty frames', () => {
      const allTargets = [
        ...TARGET_MISSILES.map(m => ({ name: m.name, meta: m.meta, dir: publicMissilesDir })),
        ...TARGET_OVERLAYS.map(o => ({ name: o.name, meta: o.meta, dir: publicOverlaysDir })),
      ]

      for (const t of allTargets) {
        const pngPath = path.join(t.dir, `${t.name}.png`)
        const buf = fs.readFileSync(pngPath)
        const { width, height, pixels } = decodeRgbaPng(buf)

        for (const group of t.meta.groups) {
          for (let fIdx = 0; fIdx < group.length; fIdx++) {
            const [fx, fy, fw, fh] = group[fIdx]!

            // Determine if this frame is non-empty
            let frameVisiblePixels = 0
            for (let y = fy; y < fy + fh; y++) {
              for (let x = fx; x < fx + fw; x++) {
                const idx = (y * width + x) * 4
                if (pixels[idx + 3]! > 0) frameVisiblePixels++
              }
            }

            if (frameVisiblePixels === 0) {
              // Empty frame: all pixels in box must be strictly alpha === 0
              continue
            }

            // For non-empty frame: inspect edge pixels (pixels with alpha > 0 adjacent to alpha === 0)
            let perimeterPixelsChecked = 0
            for (let y = fy; y < fy + fh; y++) {
              for (let x = fx; x < fx + fw; x++) {
                const idx = (y * width + x) * 4
                const a = pixels[idx + 3]!
                if (a === 0) continue

                // Check 4-neighbors for any transparent pixel
                let hasTransparentNeighbor = false
                const neighbors = [
                  [x - 1, y],
                  [x + 1, y],
                  [x, y - 1],
                  [x, y + 1],
                ]
                for (const [nx, ny] of neighbors) {
                  if (nx < 0 || nx >= width || ny < 0 || ny >= height) {
                    hasTransparentNeighbor = true
                    break
                  }
                  const nIdx = (ny * width + nx) * 4
                  if (pixels[nIdx + 3] === 0) {
                    hasTransparentNeighbor = true
                    break
                  }
                }

                if (hasTransparentNeighbor) {
                  perimeterPixelsChecked++
                  const maxRgb = Math.max(pixels[idx]!, pixels[idx + 1]!, pixels[idx + 2]!)
                  // Edge pixel bordering transparency MUST NOT have maxRgb <= 4
                  expect(
                    maxRgb,
                    `Perimeter pixel at (${x},${y}) in ${t.name} (frame ${fIdx}) has maxRgb=${maxRgb} <= 4 with alpha=${a}`
                  ).toBeGreaterThan(4)
                }
              }
            }

            expect(
              perimeterPixelsChecked,
              `Non-empty frame at (${fx},${fy}) (fIdx: ${fIdx}) in ${t.name} must have non-empty perimeter`
            ).toBeGreaterThan(0)
          }
        }
      }
    })

    it('1.4 Mathematical verification of threshold ramp function across all non-zero alpha pixels', () => {
      const allTargets = [
        ...TARGET_MISSILES.map(m => ({ name: m.name, dir: publicMissilesDir })),
        ...TARGET_OVERLAYS.map(o => ({ name: o.name, dir: publicOverlaysDir })),
      ]

      for (const t of allTargets) {
        const pngPath = path.join(t.dir, `${t.name}.png`)
        const buf = fs.readFileSync(pngPath)
        const { pixels } = decodeRgbaPng(buf)

        for (let i = 0; i < pixels.length; i += 4) {
          const r = pixels[i]!
          const g = pixels[i + 1]!
          const b = pixels[i + 2]!
          const a = pixels[i + 3]!
          const m = Math.max(r, g, b)

          if (m <= 4) {
            expect(a).toBe(0)
          } else if (m >= 60) {
            expect(a).toBe(255)
          } else {
            // 4 < m < 60
            const expectedAlpha = Math.min(255, Math.round(((m - 4) / (60 - 4)) * 255))
            expect(Math.abs(a - expectedAlpha)).toBeLessThanOrEqual(1)
          }
        }
      }
    })
  })

  describe('Adversarial Test 2: Frame Geometry, Bounding Box Disjointness & Pivot Offsets', () => {
    it('2.1 Atlas Frame Disjointness: No two frames within an atlas sheet overlap each other', () => {
      const allMetas: { name: string; meta: MissileMeta | OverlayMeta }[] = [
        ...TARGET_MISSILES.map(m => ({ name: m.name, meta: m.meta })),
        ...TARGET_OVERLAYS.map(o => ({ name: o.name, meta: o.meta })),
      ]

      for (const { name, meta } of allMetas) {
        const frames: { x: number; y: number; w: number; h: number; fIdx: number }[] = []
        let fIdx = 0
        for (const group of meta.groups) {
          for (const [x, y, w, h] of group) {
            frames.push({ x, y, w, h, fIdx: fIdx++ })
          }
        }

        // Quadratic collision check among all frames in sheet
        for (let i = 0; i < frames.length; i++) {
          const a = frames[i]!
          for (let j = i + 1; j < frames.length; j++) {
            const b = frames[j]!
            const overlaps = !(
              a.x + a.w <= b.x ||
              b.x + b.w <= a.x ||
              a.y + a.h <= b.y ||
              b.y + b.h <= a.y
            )
            expect(
              overlaps,
              `Frame ${a.fIdx} [${a.x},${a.y},${a.w},${a.h}] overlaps Frame ${b.fIdx} [${b.x},${b.y},${b.w},${b.h}] in sheet ${name}`
            ).toBe(false)
          }
        }
      }
    })

    it('2.2 Bounding Box Rect Invariants: x>=0, y>=0, w>0, h>0 and strictly within sheet dimensions', () => {
      const allMetas = [
        ...TARGET_MISSILES.map(m => ({ name: m.name, meta: m.meta })),
        ...TARGET_OVERLAYS.map(o => ({ name: o.name, meta: o.meta })),
      ]

      for (const { name, meta } of allMetas) {
        expect(meta.width).toBeGreaterThan(0)
        expect(meta.height).toBeGreaterThan(0)
        expect(meta.width).toBeLessThanOrEqual(4096)
        expect(meta.height).toBeLessThanOrEqual(4096)

        for (const group of meta.groups) {
          for (const [x, y, w, h] of group) {
            expect(Number.isInteger(x)).toBe(true)
            expect(Number.isInteger(y)).toBe(true)
            expect(Number.isInteger(w)).toBe(true)
            expect(Number.isInteger(h)).toBe(true)
            expect(x).toBeGreaterThanOrEqual(0)
            expect(y).toBeGreaterThanOrEqual(0)
            expect(w).toBeGreaterThan(0)
            expect(h).toBeGreaterThan(0)
            expect(x + w).toBeLessThanOrEqual(meta.width)
            expect(y + h).toBeLessThanOrEqual(meta.height)
          }
        }
      }
    })

    it('2.3 Coordinate Pivot Offsets (ax, ay) Bounds & Sanity: finite, integer, and within Diablo II coordinates', () => {
      const allMetas = [
        ...TARGET_MISSILES.map(m => ({ name: m.name, meta: m.meta })),
        ...TARGET_OVERLAYS.map(o => ({ name: o.name, meta: o.meta })),
      ]

      for (const { name, meta } of allMetas) {
        for (const group of meta.groups) {
          for (const [, , , , ax, ay] of group) {
            expect(typeof ax).toBe('number')
            expect(typeof ay).toBe('number')
            expect(Number.isNaN(ax)).toBe(false)
            expect(Number.isNaN(ay)).toBe(false)
            expect(Number.isFinite(ax)).toBe(true)
            expect(Number.isFinite(ay)).toBe(true)
            expect(Number.isInteger(ax)).toBe(true)
            expect(Number.isInteger(ay)).toBe(true)
            // Diablo II frame anchor offsets range from -1000 to +1000 pixels
            expect(ax).toBeGreaterThanOrEqual(-1000)
            expect(ax).toBeLessThanOrEqual(1000)
            expect(ay).toBeGreaterThanOrEqual(-1000)
            expect(ay).toBeLessThanOrEqual(1000)
          }
        }
      }
    })

    it('2.4 Sheet Activity: every missile and overlay atlas sheet contains non-empty frames and active render data', () => {
      const allTargets = [
        ...TARGET_MISSILES.map(m => ({ name: m.name, meta: m.meta, dir: publicMissilesDir })),
        ...TARGET_OVERLAYS.map(o => ({ name: o.name, meta: o.meta, dir: publicOverlaysDir })),
      ]

      for (const t of allTargets) {
        const pngPath = path.join(t.dir, `${t.name}.png`)
        const buf = fs.readFileSync(pngPath)
        const { width, pixels } = decodeRgbaPng(buf)

        let totalVisiblePixels = 0
        let nonZeroFramesCount = 0

        for (const group of t.meta.groups) {
          for (let fIdx = 0; fIdx < group.length; fIdx++) {
            const [x, y, w, h] = group[fIdx]!
            let frameVisible = 0
            for (let row = y; row < y + h; row++) {
              for (let col = x; col < x + w; col++) {
                const idx = (row * width + col) * 4
                if (pixels[idx + 3]! > 0) frameVisible++
              }
            }
            if (frameVisible > 0) {
              nonZeroFramesCount++
              totalVisiblePixels += frameVisible
            }
          }
        }

        expect(totalVisiblePixels, `${t.name} must have positive visible pixel count`).toBeGreaterThan(100)
        expect(nonZeroFramesCount, `${t.name} must have multiple active frames`).toBeGreaterThanOrEqual(1)
      }
    })
  })

  describe('Adversarial Test 3: Directional Groups, Frame Counts & Metadata Parity', () => {
    it('3.1 Verifies directional group structure across all new missiles', () => {
      for (const m of TARGET_MISSILES) {
        expect(m.meta.directions).toBeGreaterThanOrEqual(1)
        expect(m.meta.groups.length).toBe(m.meta.directions)
        expect(m.meta.framesPerDirection).toBeGreaterThan(0)

        // All directional groups must have exactly framesPerDirection frames
        for (let d = 0; d < m.meta.directions; d++) {
          const group = m.meta.groups[d]!
          expect(group.length).toBe(m.meta.framesPerDirection)
        }
      }
    })

    it('3.2 Verifies overlay single-direction and preDraw configuration', () => {
      for (const o of TARGET_OVERLAYS) {
        expect(o.meta.directions).toBe(1)
        expect(o.meta.frames).toBeGreaterThan(0)
        expect(o.meta.framesPerDirection).toBe(o.meta.frames)
        expect(o.meta.groups.length).toBe(1)
        expect(o.meta.groups[0]!.length).toBe(o.meta.frames)
        expect(o.meta.preDraw).toBe(o.preDraw)

        // Specific preDraw check: Bone Armor back must be true, front must be false
        if (o.name === 'bonearmor_back') {
          expect(o.meta.preDraw).toBe(true)
        } else {
          expect(o.meta.preDraw).toBe(false)
        }
      }
    })

    it('3.3 JSON Disk vs TypeScript In-Memory Metadata Exact Parity', () => {
      for (const m of TARGET_MISSILES) {
        const jsonPath = path.join(publicMissilesDir, `${m.name}.json`)
        const json = JSON.parse(fs.readFileSync(jsonPath, 'utf-8'))

        expect(json.name).toBe(m.meta.name)
        expect(json.celFile).toBe(m.meta.celFile)
        expect(json.width).toBe(m.meta.width)
        expect(json.height).toBe(m.meta.height)
        expect(json.directions).toBe(m.meta.directions)
        expect(json.framesPerDirection).toBe(m.meta.framesPerDirection)
        expect(json.animSpeed).toBe(m.meta.animSpeed)
        expect(json.groups).toEqual(m.meta.groups)
      }

      for (const o of TARGET_OVERLAYS) {
        const jsonPath = path.join(publicOverlaysDir, `${o.name}.json`)
        const json = JSON.parse(fs.readFileSync(jsonPath, 'utf-8'))

        expect(json.name).toBe(o.meta.name)
        expect(json.celFile).toBe(o.meta.celFile)
        expect(json.width).toBe(o.meta.width)
        expect(json.height).toBe(o.meta.height)
        expect(json.directions).toBe(o.meta.directions)
        expect(json.frames).toBe(o.meta.frames)
        expect(json.framesPerDirection).toBe(o.meta.framesPerDirection)
        expect(json.animRate).toBe(o.meta.animRate)
        expect(json.trans).toBe(o.meta.trans)
        expect(json.preDraw).toBe(o.meta.preDraw)
        expect(json.groups).toEqual(o.meta.groups)
      }
    })

    it('3.4 Dual Storage Byte & Content Parity between public/ and samples/d2-packs/', () => {
      for (const m of TARGET_MISSILES) {
        const pubPng = fs.readFileSync(path.join(publicMissilesDir, `${m.name}.png`))
        const packPng = fs.readFileSync(path.join(packMissilesDir, `${m.name}.png`))
        expect(Buffer.compare(pubPng, packPng), `Missile ${m.name}.png differs between public and samples/d2-packs`).toBe(0)

        const pubJson = fs.readFileSync(path.join(publicMissilesDir, `${m.name}.json`))
        const packJson = fs.readFileSync(path.join(packMissilesDir, `${m.name}.json`))
        expect(Buffer.compare(pubJson, packJson), `Missile ${m.name}.json differs between public and samples/d2-packs`).toBe(0)
      }

      for (const o of TARGET_OVERLAYS) {
        const pubPng = fs.readFileSync(path.join(publicOverlaysDir, `${o.name}.png`))
        const packPng = fs.readFileSync(path.join(packOverlaysDir, `${o.name}.png`))
        expect(Buffer.compare(pubPng, packPng), `Overlay ${o.name}.png differs between public and samples/d2-packs`).toBe(0)

        const pubJson = fs.readFileSync(path.join(publicOverlaysDir, `${o.name}.json`))
        const packJson = fs.readFileSync(path.join(packOverlaysDir, `${o.name}.json`))
        expect(Buffer.compare(pubJson, packJson), `Overlay ${o.name}.json differs between public and samples/d2-packs`).toBe(0)
      }
    })
  })
})