import React, { useCallback, useRef, useState } from 'react'
import { StyleSheet, Text, View } from 'react-native'
import { Camera, useCameraPermission, useCameraDevice, useCameraFormat, PhotoFile, VideoFile, CameraRuntimeError } from 'react-native-vision-camera'
import { RecordingButton } from './capture-button'
import { useIsForeground } from './is-foreground'
import { useIsFocused } from '@react-navigation/native'


export default function CameraScreen(): React.ReactElement {
  const camera = useRef<Camera>(null)
  const { hasPermission, requestPermission } = useCameraPermission()
  const [isCameraInitialized, setIsCameraInitialized] = useState(false)

  const isForeground = useIsForeground()
  const isFocused = useIsFocused();
  const isActive = isForeground && isFocused

  const onError = useCallback((error: CameraRuntimeError) => {
    console.error(error)
  }, [])

  const onInitialized = useCallback(() => {
    console.log('Camera initialized!')
    setIsCameraInitialized(true)
  }, [])

  const onMediaCaptured = useCallback(
    (media: PhotoFile | VideoFile) => {
      console.log(`Media captured! ${JSON.stringify(media)}`)
    },
    [],
  )

  if (!hasPermission) {
    requestPermission()
    // Error handling in case they refuse to give permission
  }

  const device = useCameraDevice('back')
  const format = useCameraFormat(device, [
    { videoResolution: { width: 3048, height: 2160 } },
    { fps: 60 }
  ])

  if (device === null) {
    return <Text>Camera not available. Does user have permissions:  {hasPermission}</Text>
  }

  return (
    hasPermission && (
      <View style={styles.container}>
        <Camera
          ref={camera}
          style={StyleSheet.absoluteFill}
          device={device}
          format={format}
          onInitialized={onInitialized}
          onError={onError}
          video={true}
          photo={false}
          orientation='portrait' // TODO: #60
          isActive={isActive}
        />
        <RecordingButton
          style={styles.captureButton}
          camera={camera}
          onMediaCaptured={onMediaCaptured}
          enabled={isCameraInitialized}
        />
      </View>

    )
  )
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: 'black',
  },
  captureButton: {
    position: 'absolute',
    alignSelf: 'center',
    bottom: 20, // Should come from SafeAreaProvider
  },
})