import React, { useCallback, useMemo, useState } from 'react';
import { StyleSheet, View, Image, ActivityIndicator, PermissionsAndroid, Platform } from 'react-native';
import { Navigation, NavigationFunctionComponent, OptionsModalPresentationStyle } from 'react-native-navigation';
import Video from 'react-native-video';
import { SAFE_AREA_PADDING } from './Constants';
import { useIsForeground } from './hooks/useIsForeground';
import { useIsScreenFocused } from './hooks/useIsScreenFocused';
import { PressableOpacity } from './views/PressableOpacity';
import IonIcon from 'react-native-vector-icons/Ionicons';
import { Alert } from 'react-native';
import CameraRoll from '@react-native-community/cameraroll';

interface MediaProps {
  path: string,
  type: 'video' | 'photo'
}

const requestSavePermission = async (): Promise<boolean> => {
  if (Platform.OS !== "android") {
    return true;
  }
  const permission = PermissionsAndroid.PERMISSIONS.WRITE_EXTERNAL_STORAGE;
  let hasPermission = await PermissionsAndroid.check(permission);
  if (!hasPermission) {
    const permissionRequestResult = await PermissionsAndroid.request(permission);
    hasPermission = permissionRequestResult === "granted";
  }
  return hasPermission;
}

export const Media: NavigationFunctionComponent<MediaProps> = ({ componentId, type, path }) => {
  const [hasMediaLoaded, setHasMediaLoaded] = useState(false);
  const isForeground = useIsForeground();
  const isScreenFocused = useIsScreenFocused(componentId);
  const isVideoPaused = !isForeground || !isScreenFocused;
  const [savingState, setSavingState] = useState<"none" | "saving" | "saved">("none");

  const onClosePressed = useCallback(() => {
    Navigation.dismissModal(componentId);
  }, [componentId]);

  const onMediaLoadEnd = useCallback(() => {
    console.log(`media has loaded.`);
    setHasMediaLoaded(true);
  }, []);

  const onSavePressed = useCallback(async () => {
    try {
      setSavingState("saving");

      const hasPermission = await requestSavePermission();
      if (!hasPermission) {
        Alert.alert('Permission denied!', 'Vision Camera does not have permission to save the media to your camera roll.');
        return;
      }
      await CameraRoll.save(`file://${path}`, {
        type: type,
      });
      setSavingState("saved");
    } catch (e) {
      setSavingState("none");
      Alert.alert(
        "Failed to save!",
        `An unexpected error occured while trying to save your ${type}. ${e?.message ?? JSON.stringify(e)}`
      );
    }
  }, [path, type]);

  const source = useMemo(() => ({ uri: `file://${path}` }), [path]);

  const screenStyle = useMemo(() => ({ opacity: hasMediaLoaded ? 1 : 0 }), [
    hasMediaLoaded,
  ]);

  return (
    <View style={[styles.container, screenStyle]}>
      {type === "photo" && (
        <Image
          source={source}
          style={StyleSheet.absoluteFill}
          resizeMode="cover"
          onLoadEnd={onMediaLoadEnd} />
      )}
      {type === "video" && (
        <Video source={source}
          style={StyleSheet.absoluteFill}
          paused={isVideoPaused}
          resizeMode="cover"
          posterResizeMode="cover"
          allowsExternalPlayback={false}
          automaticallyWaitsToMinimizeStalling={false}
          disableFocus={true}
          repeat={true}
          useTextureView={false}
          controls={false}
          playWhenInactive={true}
          ignoreSilentSwitch="ignore"
          onReadyForDisplay={onMediaLoadEnd} />
      )}

      <PressableOpacity
        style={styles.closeButton}
        onPress={onClosePressed}>
        <IonIcon
          name="close"
          size={35}
          color="white"
          style={styles.icon} />
      </PressableOpacity>

      <PressableOpacity
        style={styles.saveButton}
        onPress={onSavePressed}
        disabled={savingState !== "none"}>
        {savingState === "none" && (
          <IonIcon
            name="download"
            size={35}
            color="white"
            style={styles.icon}
          />
        )}
        {savingState === "saved" && (
          <IonIcon
            name="checkmark"
            size={35}
            color="white"
            style={styles.icon}
          />
        )}
        {savingState === "saving" && (
          <ActivityIndicator color="white" />
        )}
      </PressableOpacity>
    </View>
  );
}

Media.options = {
  modal: {
    swipeToDismiss: false,
  },
  modalPresentationStyle: OptionsModalPresentationStyle.overCurrentContext,
  animations: {
    showModal: {
      waitForRender: true,
      enabled: false,
    },
    dismissModal: {
      enabled: false,
    },
  },
  layout: {
    backgroundColor: "transparent",
    componentBackgroundColor: "transparent",
  },
};

const styles = StyleSheet.create({
  container: {
    flex: 1,
    alignItems: 'center',
    justifyContent: 'center',
    backgroundColor: 'white',
  },
  closeButton: {
    position: 'absolute',
    top: SAFE_AREA_PADDING.paddingTop,
    left: SAFE_AREA_PADDING.paddingLeft,
    width: 40,
    height: 40,
  },
  saveButton: {
    position: 'absolute',
    bottom: SAFE_AREA_PADDING.paddingBottom,
    left: SAFE_AREA_PADDING.paddingLeft,
    width: 40,
    height: 40,
  },
  icon: {
    textShadowColor: "black",
    textShadowOffset: {
      height: 0,
      width: 0,
    },
    textShadowRadius: 1,
  },
});