/**
 * Offline Cast Overlay Asset & Data Baking Script.
 *
 * Extracts authentic Diablo II v1.13c cast overlay DCC sprites from d2data.mpq:
 * - FireCast_for_Sorceress.dcc (fire_cast_1, 14 frames, box: [-55, -127, 117, 164])
 * - FireCast2.dcc (fire_cast_2, 16 frames, box: [-74, -89, 145, 133])
 * - IceCastNew01.dcc (ice_cast_1, 15 frames, box: [-49, -90, 97, 55])
 * - IceCastNew02.dcc (ice_cast_2, 15 frames, box: [-58, -100, 115, 123])
 * - IceCastNew03.dcc (ice_cast_3, 16 frames, box: [-63, -113, 127, 148])
 * - LightningCast.dcc (light_cast_1, 10 frames, box: [-79, -107, 164, 144])
 * - LightningCastRunesFront.dcc (light_cast_2, 10 frames, box: [-73, -154, 147, 190])
 * - Teleport.dcc (teleport, 18 frames, box: [-61, -108, 136, 154])
 *
 * Bakes them into indexed-color PNG atlases and JSON metadata under:
 * - public/overlays/
 * - samples/d2-packs/overlays/
 *
 * And generates typed metadata in src/render/overlays-meta.ts.
 * Enforces Zero Runtime MPQ/DLL Architectural Invariant.
 */

import { mkdirSync, writeFileSync } from 'node:fs'
import { join } from 'node:path'
import { MpqArchive } from '../src/mpq/archive.ts'
import { fileSource } from '../src/mpq/file-source.ts'
import { decodeDcc } from '../src/formats/dcc.ts'
import { decodePl2 } from '../src/formats/pl2.ts'
import { packSheetToPng } from './pack-entity-assets.ts'
import type { SpriteFrame, SpriteSheet } from '../src/formats/sprite.ts'

export interface OverlayFrameMeta {
  readonly x: number
  readonly y: number
  readonly w: number
  readonly h: number
  readonly anchorX: number
  readonly anchorY: number
}

export type OverlayFrameTuple = readonly [
  x: number,
  y: number,
  width: number,
  height: number,
  anchorX: number,
  anchorY: number,
]

export interface OverlayBox {
  readonly left: number
  readonly top: number
  readonly width: number
  readonly height: number
}

export interface OverlayMeta {
  readonly name: string
  readonly celFile: string
  readonly width: number
  readonly height: number
  readonly directions: number
  readonly frames: number
  readonly framesPerDirection: number
  readonly animRate: number
  readonly trans: number
  readonly preDraw: boolean
  readonly lightRadius: number
  readonly lightColor: readonly [number, number, number]
  readonly box: OverlayBox
  readonly groups: readonly (readonly OverlayFrameTuple[])[]
}

export interface OverlayTarget {
  readonly name: string
  readonly celFile: string
  readonly aliases?: readonly string[]
  readonly animRate: number
  readonly trans: number
  readonly preDraw: boolean
  readonly lightRadius: number
  readonly lightColor: readonly [number, number, number]
}

export const OVERLAY_TARGETS: readonly OverlayTarget[] = [
  {
    name: 'fire_cast_1',
    celFile: 'FireCast_for_Sorceress',
    animRate: 16,
    trans: 3,
    preDraw: false,
    lightRadius: 9,
    lightColor: [255, 178, 64] as const,
  },
  {
    name: 'fire_cast_2',
    celFile: 'FireCast2',
    animRate: 16,
    trans: 3,
    preDraw: false,
    lightRadius: 9,
    lightColor: [255, 178, 64] as const,
  },
  {
    name: 'ice_cast_1',
    celFile: 'IceCastNew01',
    animRate: 16,
    trans: 3,
    preDraw: false,
    lightRadius: 9,
    lightColor: [81, 81, 255] as const,
  },
  {
    name: 'ice_cast_2',
    celFile: 'IceCastNew02',
    animRate: 16,
    trans: 3,
    preDraw: false,
    lightRadius: 9,
    lightColor: [81, 81, 255] as const,
  },
  {
    name: 'ice_cast_3',
    celFile: 'IceCastNew03',
    animRate: 16,
    trans: 3,
    preDraw: false,
    lightRadius: 9,
    lightColor: [81, 81, 255] as const,
  },
  {
    name: 'light_cast_1',
    celFile: 'LightningCast',
    animRate: 16,
    trans: 3,
    preDraw: false,
    lightRadius: 9,
    lightColor: [255, 255, 255] as const,
  },
  {
    name: 'light_cast_2',
    celFile: 'LightningCastRunesFront',
    animRate: 16,
    trans: 3,
    preDraw: false,
    lightRadius: 9,
    lightColor: [255, 255, 255] as const,
  },
  {
    name: 'teleport',
    celFile: 'Teleport',
    animRate: 16,
    trans: 3,
    preDraw: false,
    lightRadius: 5,
    lightColor: [255, 255, 200] as const,
  },
  // 20 Authentic Diablo II v1.13c Paladin Aura Overlays
  {
    name: 'might',
    celFile: 'AuraMightFront',
    aliases: ['aura_might_front', 'aura_might'],
    animRate: 16,
    trans: 3,
    preDraw: false,
    lightRadius: 0,
    lightColor: [255, 255, 255] as const,
  },
  {
    name: 'prayer',
    celFile: 'AuraPrayerFront',
    aliases: ['aura_prayer_front', 'aura_prayer'],
    animRate: 8,
    trans: 3,
    preDraw: false,
    lightRadius: 0,
    lightColor: [255, 255, 255] as const,
  },
  {
    name: 'resist_fire',
    celFile: 'AuraResistFireFront',
    aliases: ['aura_resistfire'],
    animRate: 16,
    trans: 3,
    preDraw: true,
    lightRadius: 6,
    lightColor: [255, 193, 103] as const,
  },
  {
    name: 'holy_fire',
    celFile: 'AuraHolyFireFront',
    aliases: ['aura_holyfire_front', 'aura_holyfire'],
    animRate: 16,
    trans: 3,
    preDraw: false,
    lightRadius: 0,
    lightColor: [255, 255, 255] as const,
  },
  {
    name: 'thorns',
    celFile: 'AuraThornsFront',
    aliases: ['aura_thorns_front', 'aura_thorns'],
    animRate: 16,
    trans: 3,
    preDraw: false,
    lightRadius: 0,
    lightColor: [255, 255, 255] as const,
  },
  {
    name: 'defiance',
    celFile: 'AuraDefianceFront',
    aliases: ['aura_defiance_front', 'aura_defiance'],
    animRate: 8,
    trans: 3,
    preDraw: false,
    lightRadius: 0,
    lightColor: [255, 255, 255] as const,
  },
  {
    name: 'resist_cold',
    celFile: 'AuraResistColdBack',
    aliases: ['aura_resistcold'],
    animRate: 16,
    trans: 3,
    preDraw: true,
    lightRadius: 6,
    lightColor: [210, 210, 255] as const,
  },
  {
    name: 'blessed_aim',
    celFile: 'BlessedAim_front',
    aliases: ['blessedaimfront', 'blessed_aim_front'],
    animRate: 8,
    trans: 3,
    preDraw: false,
    lightRadius: 0,
    lightColor: [255, 255, 255] as const,
  },
  {
    name: 'cleansing',
    celFile: 'Cleansing_front',
    aliases: ['cleansingfront', 'cleansing_front'],
    animRate: 8,
    trans: 3,
    preDraw: false,
    lightRadius: 0,
    lightColor: [255, 255, 255] as const,
  },
  {
    name: 'resist_lightning',
    celFile: 'AuraResistLightningBack',
    aliases: ['aura_resistlight'],
    animRate: 16,
    trans: 3,
    preDraw: true,
    lightRadius: 6,
    lightColor: [255, 255, 200] as const,
  },
  {
    name: 'concentration',
    celFile: 'Concentration_front',
    aliases: ['concentrationfront', 'concentration_front'],
    animRate: 3,
    trans: 3,
    preDraw: false,
    lightRadius: 0,
    lightColor: [255, 255, 255] as const,
  },
  {
    name: 'holy_freeze',
    celFile: 'HolyFreeze',
    aliases: ['holyfreeze', 'holywind'],
    animRate: 8,
    trans: 3,
    preDraw: true,
    lightRadius: 0,
    lightColor: [255, 255, 255] as const,
  },
  {
    name: 'vigor',
    celFile: 'Stamina_front',
    aliases: ['staminafront', 'stamina_front', 'stamina'],
    animRate: 8,
    trans: 3,
    preDraw: false,
    lightRadius: 0,
    lightColor: [255, 255, 255] as const,
  },
  {
    name: 'holy_shock',
    celFile: 'HolyShock_front',
    aliases: ['holyshockfront', 'holyshock_front', 'holyshock'],
    animRate: 16,
    trans: 3,
    preDraw: false,
    lightRadius: 0,
    lightColor: [255, 255, 255] as const,
  },
  {
    name: 'sanctuary',
    celFile: 'SanctuaryAura_Front',
    aliases: ['sanctuaryfront', 'sanctuary_front'],
    animRate: 16,
    trans: 3,
    preDraw: true,
    lightRadius: 0,
    lightColor: [255, 255, 255] as const,
  },
  {
    name: 'meditation',
    celFile: 'Meditation',
    aliases: ['meditationfront'],
    animRate: 16,
    trans: 3,
    preDraw: false,
    lightRadius: 0,
    lightColor: [255, 255, 255] as const,
  },
  {
    name: 'fanaticism',
    celFile: 'Fanatacism_Back',
    aliases: ['fanaticismback', 'aura_fanatic', 'Fanatacism_Front'],
    animRate: 6,
    trans: 3,
    preDraw: true,
    lightRadius: 0,
    lightColor: [255, 255, 255] as const,
  },
  {
    name: 'conviction',
    celFile: 'Conviction',
    aliases: ['convictionback'],
    animRate: 6,
    trans: 3,
    preDraw: true,
    lightRadius: 0,
    lightColor: [255, 255, 255] as const,
  },
  {
    name: 'redemption',
    celFile: 'Redemption',
    aliases: ['redemptionback'],
    animRate: 16,
    trans: 3,
    preDraw: true,
    lightRadius: 0,
    lightColor: [255, 255, 255] as const,
  },
  {
    name: 'salvation',
    celFile: 'AuraResistAllFront',
    aliases: ['aura_resistall_front', 'aura_resistall'],
    animRate: 16,
    trans: 3,
    preDraw: false,
    lightRadius: 6,
    lightColor: [211, 148, 255] as const,
  },
] as const

export async function bakeOverlays(projectRoot: string = process.cwd()): Promise<Record<string, OverlayMeta>> {
  const mpqPath = join(projectRoot, 'samples', 'd2', 'd2data.mpq')
  const mpq = await MpqArchive.open(await fileSource(mpqPath))

  const palFile = mpq.find('data/global/palette/ACT1/pal.pl2')
  if (!palFile) throw new Error('data/global/palette/ACT1/pal.pl2 not found in d2data.mpq')
  const pl2 = decodePl2(await mpq.read(palFile))

  const publicOutDir = join(projectRoot, 'public', 'overlays')
  const packOutDir = join(projectRoot, 'samples', 'd2-packs', 'overlays')
  mkdirSync(publicOutDir, { recursive: true })
  mkdirSync(packOutDir, { recursive: true })

  const metaRecord: Record<string, OverlayMeta> = {}

  for (const target of OVERLAY_TARGETS) {
    const f = mpq.find(`data/global/overlays/${target.celFile}.dcc`)
    if (!f) throw new Error(`Overlay DCC not found: data/global/overlays/${target.celFile}.dcc`)

    const dcc = decodeDcc(await mpq.read(f))
    const firstDir = dcc.directions[0]
    if (!firstDir) throw new Error(`Overlay DCC has no directions: ${target.celFile}`)

    const box: OverlayBox = {
      left: firstDir.box.left,
      top: firstDir.box.top,
      width: firstDir.box.width,
      height: firstDir.box.height,
    }

    const groups = dcc.directions.map(dir => ({
      frames: dir.frames.map(
        (frame): SpriteFrame => ({
          width: frame.frame.width,
          height: frame.frame.height,
          indices: frame.frame.indices,
          mask: frame.frame.mask,
          anchorX: dir.box.left,
          anchorY: dir.box.top,
        }),
      ),
    }))

    const sheet: SpriteSheet = { groups, width: null }
    const packed = packSheetToPng(sheet, pl2.rgb)

    const meta: OverlayMeta = {
      name: target.name,
      celFile: target.celFile,
      width: packed.width,
      height: packed.height,
      directions: dcc.directions.length,
      frames: firstDir.frames.length,
      framesPerDirection: firstDir.frames.length,
      animRate: target.animRate,
      trans: target.trans,
      preDraw: target.preDraw,
      lightRadius: target.lightRadius,
      lightColor: target.lightColor,
      box,
      groups: packed.groups,
    }

    metaRecord[target.name] = meta
    metaRecord[target.celFile] = meta
    if (target.celFile.toLowerCase() !== target.celFile) {
      metaRecord[target.celFile.toLowerCase()] = meta
    }

    const allKeys = new Set<string>([target.name, target.celFile, ...(target.aliases ?? [])])
    for (const alias of target.aliases ?? []) {
      metaRecord[alias] = meta
    }

    const jsonStr = JSON.stringify(meta, null, 2)

    // Write primary name and aliases to both public/overlays/ and samples/d2-packs/overlays/
    for (const fileKey of allKeys) {
      writeFileSync(join(publicOutDir, `${fileKey}.png`), packed.png)
      writeFileSync(join(publicOutDir, `${fileKey}.json`), jsonStr, 'utf-8')
      writeFileSync(join(packOutDir, `${fileKey}.png`), packed.png)
      writeFileSync(join(packOutDir, `${fileKey}.json`), jsonStr, 'utf-8')
    }

    console.log(
      `[Overlay Packer] Baked ${target.name} (${target.celFile}.dcc): ` +
      `${meta.frames} frames, box [${box.left}, ${box.top}, ${box.width}, ${box.height}], ` +
      `${packed.width}x${packed.height}, ${packed.png.byteLength} bytes PNG`,
    )
  }

  const TARGET_CONST_NAMES: Record<string, string> = {
    fire_cast_1: 'FIRE_CAST_1_META',
    fire_cast_2: 'FIRE_CAST_2_META',
    ice_cast_1: 'ICE_CAST_1_META',
    ice_cast_2: 'ICE_CAST_2_META',
    ice_cast_3: 'ICE_CAST_3_META',
    light_cast_1: 'LIGHT_CAST_1_META',
    light_cast_2: 'LIGHT_CAST_2_META',
    teleport: 'TELEPORT_META',
    might: 'MIGHT_AURA_META',
    prayer: 'PRAYER_AURA_META',
    resist_fire: 'RESIST_FIRE_AURA_META',
    holy_fire: 'HOLY_FIRE_AURA_META',
    thorns: 'THORNS_AURA_META',
    defiance: 'DEFIANCE_AURA_META',
    resist_cold: 'RESIST_COLD_AURA_META',
    blessed_aim: 'BLESSED_AIM_AURA_META',
    cleansing: 'CLEANSING_AURA_META',
    resist_lightning: 'RESIST_LIGHTNING_AURA_META',
    concentration: 'CONCENTRATION_AURA_META',
    holy_freeze: 'HOLY_FREEZE_AURA_META',
    vigor: 'VIGOR_AURA_META',
    holy_shock: 'HOLY_SHOCK_AURA_META',
    sanctuary: 'SANCTUARY_AURA_META',
    meditation: 'MEDITATION_AURA_META',
    fanaticism: 'FANATICISM_AURA_META',
    conviction: 'CONVICTION_AURA_META',
    redemption: 'REDEMPTION_AURA_META',
    salvation: 'SALVATION_AURA_META',
  }

  const individualConsts = OVERLAY_TARGETS.map(t => {
    const constName = TARGET_CONST_NAMES[t.name] ?? `${t.name.toUpperCase()}_META`
    return `export const ${constName}: OverlayMeta = ${JSON.stringify(metaRecord[t.name], null, 2)}`
  }).join('\n\n')

  const overlayMetasEntries: string[] = []
  const seenKeys = new Set<string>()
  for (const t of OVERLAY_TARGETS) {
    const constName = TARGET_CONST_NAMES[t.name] ?? `${t.name.toUpperCase()}_META`
    const keys = new Set<string>([t.name, t.celFile, ...(t.aliases ?? [])])
    for (const k of keys) {
      if (!seenKeys.has(k)) {
        seenKeys.add(k)
        overlayMetasEntries.push(`  ${JSON.stringify(k)}: ${constName},`)
      }
      const lower = k.toLowerCase()
      if (!seenKeys.has(lower)) {
        seenKeys.add(lower)
        overlayMetasEntries.push(`  ${JSON.stringify(lower)}: ${constName},`)
      }
    }
  }

  // Generate src/render/overlays-meta.ts
  const metaTsContent = `/**
 * Authentic Diablo II v1.13c Cast & Aura Overlay Atlas Metadata.
 * Auto-generated by scripts/pack-overlays.ts.
 * Enforces Zero Runtime MPQ/DLL Architectural Invariant.
 */

export interface OverlayFrameMeta {
  readonly x: number
  readonly y: number
  readonly w: number
  readonly h: number
  readonly anchorX: number
  readonly anchorY: number
}

export type OverlayFrameTuple = readonly [
  x: number,
  y: number,
  width: number,
  height: number,
  anchorX: number,
  anchorY: number,
]

export interface OverlayBox {
  readonly left: number
  readonly top: number
  readonly width: number
  readonly height: number
}

export interface OverlayMeta {
  readonly name: string
  readonly celFile: string
  readonly width: number
  readonly height: number
  readonly directions: number
  readonly frames: number
  readonly framesPerDirection: number
  readonly animRate: number
  readonly trans: number
  readonly preDraw: boolean
  readonly lightRadius: number
  readonly lightColor: readonly [number, number, number]
  readonly box: OverlayBox
  readonly groups: readonly (readonly OverlayFrameTuple[])[]
}

${individualConsts}

export const ALL_OVERLAY_NAMES: readonly string[] = [
${OVERLAY_TARGETS.map(t => `  ${JSON.stringify(t.name)},`).join('\n')}
]

export const OVERLAY_METAS: Readonly<Record<string, OverlayMeta>> = {
${overlayMetasEntries.join('\n')}
}
`
  const metaTsPath = join(projectRoot, 'src', 'render', 'overlays-meta.ts')
  writeFileSync(metaTsPath, metaTsContent, 'utf-8')
  console.log(`[Overlay Packer] Wrote ${metaTsPath}`)

  return metaRecord
}

// Execute standalone if called from CLI
if (process.argv[1]?.endsWith('pack-overlays.ts')) {
  bakeOverlays().catch((err: unknown) => {
    console.error('Bake overlays failed:', err)
    process.exit(1)
  })
}