import { dlopen, FFIType } from 'bun:ffi'
import { existsSync, statSync } from 'node:fs'
import path from 'node:path'
import { fileURLToPath } from 'node:url'

export const MAC_WINDOW_CORNER_RADIUS = 15
export const MAC_TRAFFIC_LIGHT_OFFSET = { x: 14, y: 12 }

const DYLIB_NAME = 'libMacWindowEffects.dylib'
const MIN_DYLIB_BYTES = 10_000

function resolveDylibPath() {
  const candidates = new Set()
  const moduleDir = path.dirname(fileURLToPath(import.meta.url))

  candidates.add(path.join(moduleDir, DYLIB_NAME))
  candidates.add(path.join(moduleDir, '../bun', DYLIB_NAME))
  candidates.add(path.join(moduleDir, '../../bun', DYLIB_NAME))
  candidates.add(path.join(process.cwd(), 'src/bun', DYLIB_NAME))

  for (const execPath of [process.execPath, process.argv0].filter(Boolean)) {
    const execDir = path.dirname(execPath)
    candidates.add(
      path.join(execDir, '../Resources/app/bun', DYLIB_NAME)
    )
    candidates.add(path.join(execDir, 'Resources/app/bun', DYLIB_NAME))
    candidates.add(path.join(execDir, DYLIB_NAME))
  }

  for (const candidate of candidates) {
    const resolved = path.resolve(candidate)
    if (!existsSync(resolved)) {
      continue
    }

    try {
      if (statSync(resolved).size >= MIN_DYLIB_BYTES) {
        return resolved
      }
    } catch {
      // Ignore unreadable paths and keep searching.
    }
  }

  return null
}

function loadMacWindowEffectsLibrary() {
  const dylibPath = resolveDylibPath()
  if (!dylibPath) {
    console.warn(
      'macOS vibrancy: native effects library not found; using transparent window only.'
    )
    return null
  }

  try {
    return {
      path: dylibPath,
      lib: dlopen(dylibPath, {
        enableWindowVibrancy: {
          args: [FFIType.ptr, FFIType.f64],
          returns: FFIType.bool
        },
        ensureWindowShadow: {
          args: [FFIType.ptr],
          returns: FFIType.bool
        },
        setWindowCornerRadius: {
          args: [FFIType.ptr, FFIType.f64],
          returns: FFIType.bool
        },
        setWindowTrafficLightsPosition: {
          args: [FFIType.ptr, FFIType.f64, FFIType.f64],
          returns: FFIType.bool
        },
        setNativeWindowDragRegion: {
          args: [FFIType.ptr, FFIType.f64, FFIType.f64],
          returns: FFIType.bool
        }
      })
    }
  } catch (error) {
    console.warn(
      `macOS vibrancy: failed to load native effects library (${dylibPath}):`,
      error
    )
    return null
  }
}

function applyTrafficLightsPosition(lib, mainWindow, attempt = 0) {
  const applied = lib.symbols.setWindowTrafficLightsPosition(
    mainWindow.ptr,
    MAC_TRAFFIC_LIGHT_OFFSET.x,
    MAC_TRAFFIC_LIGHT_OFFSET.y
  )

  if (applied || attempt >= 10) {
    return applied
  }

  setTimeout(() => applyTrafficLightsPosition(lib, mainWindow, attempt + 1), 50)
  return false
}

export function applyMacOSWindowEffects(mainWindow) {
  if (process.platform !== 'darwin' || !mainWindow?.ptr) {
    return
  }

  const loaded = loadMacWindowEffectsLibrary()
  if (!loaded) {
    return
  }

  const { path: dylibPath, lib } = loaded

  try {
    const vibrancyEnabled = lib.symbols.enableWindowVibrancy(
      mainWindow.ptr,
      MAC_WINDOW_CORNER_RADIUS
    )
    const shadowEnabled = lib.symbols.ensureWindowShadow(mainWindow.ptr)
    const trafficLightsScheduled = applyTrafficLightsPosition(lib, mainWindow)

    mainWindow.on?.('resize', () => {
      lib.symbols.setWindowCornerRadius(
        mainWindow.ptr,
        MAC_WINDOW_CORNER_RADIUS
      )
      lib.symbols.setWindowTrafficLightsPosition(
        mainWindow.ptr,
        MAC_TRAFFIC_LIGHT_OFFSET.x,
        MAC_TRAFFIC_LIGHT_OFFSET.y
      )
    })

    console.log(
      `macOS vibrancy applied (dylib=${dylibPath}, vibrancy=${vibrancyEnabled}, shadow=${shadowEnabled}, trafficLights=${trafficLightsScheduled}, cornerRadius=${MAC_WINDOW_CORNER_RADIUS})`
    )
  } catch (error) {
    console.warn(
      'macOS vibrancy: failed to apply native window effects:',
      error
    )
  }
}