import { useCallback, useMemo } from "react";
import {
  ActivityIndicator,
  Dimensions,
  Pressable,
  ScrollView,
  StyleSheet,
  Text,
  View,
} from "react-native";
import { useSafeAreaInsets } from "react-native-safe-area-context";
import { useRouter, useLocalSearchParams } from "expo-router";
import {
  Canvas,
  Image as SkImage,
  Shader,
  Fill,
  useImage,
} from "@shopify/react-native-skia";
import Animated, { FadeIn, FadeInUp } from "react-native-reanimated";
import { ArrowLeft, Check, Export } from "phosphor-react-native";
import { GlassBottomSheet, GlassButton, GlassCard, GlassPill, GlassSlider } from "@/components/glass";
import { useWallpaperStore } from "@/stores/wallpaper.store";
import { useAnimation } from "@/hooks/useAnimation";
import { useGyroscope } from "@/hooks/useGyroscope";
import { useWallpaperExport } from "@/hooks/useWallpaperExport";
import { shaders } from "@/shaders";
import {
  ANIMATION_META,
  type AnimationType,
} from "@/types/wallpaper";
import { colors, typography, spacing, layout } from "@/theme";

const { width: SCREEN_WIDTH, height: SCREEN_HEIGHT } = Dimensions.get("window");

const AVAILABLE_ANIMATIONS: AnimationType[] = [
  "ken-burns",
  "color-shift",
  "particles",
  "vignette-pulse",
  "glitch",
];

export default function EditorScreen() {
  const insets = useSafeAreaInsets();
  const router = useRouter();
  const { id } = useLocalSearchParams<{ id: string }>();

  const {
    sourceUri,
    animation,
    uniforms,
    particlePreset,
    setAnimation,
    setUniform,
    setParticlePreset,
    saveWallpaper,
  } = useWallpaperStore();

  const { time } = useAnimation(animation, uniforms);
  const gyro = useGyroscope(animation === "depth-parallax");
  const { status, exportAsWallpaper } = useWallpaperExport();

  const image = useImage(sourceUri);
  const shader = useMemo(() => shaders[animation], [animation]);

  const handleApply = useCallback(async () => {
    const config = saveWallpaper();
    if (config) {
      await exportAsWallpaper(config);
    }
  }, [saveWallpaper, exportAsWallpaper]);

  const handleSaveOnly = useCallback(() => {
    saveWallpaper();
    router.back();
  }, [saveWallpaper, router]);

  // No image selected — redirect back
  if (!sourceUri) {
    return (
      <View style={[styles.container, styles.centered]}>
        <GlassCard variant="medium" radius="xl" padding={32}>
          <Text style={[typography.heading, { textAlign: "center" }]}>
            Aucune image sélectionnée
          </Text>
          <Text
            style={[typography.bodySecondary, { textAlign: "center", marginTop: 8, marginBottom: 20 }]}
          >
            Retournez à la galerie pour choisir une photo
          </Text>
          <GlassButton
            label="Retour"
            onPress={() => router.back()}
            variant="primary"
            size="md"
          />
        </GlassCard>
      </View>
    );
  }

  // Image loading
  if (!image) {
    return (
      <View style={[styles.container, styles.centered]}>
        <ActivityIndicator color={colors.text.secondary} size="large" />
        <Text style={[typography.bodySecondary, { marginTop: 16 }]}>
          Chargement de l'image...
        </Text>
      </View>
    );
  }

  return (
    <View style={styles.container}>
      {/* Full-screen animated preview */}
      <Canvas style={styles.canvas}>
        {shader && (
          <Fill>
            <Shader
              source={shader}
              uniforms={{
                resolution: [SCREEN_WIDTH, SCREEN_HEIGHT],
                time: time.value,
                intensity: uniforms.intensity,
                speed: uniforms.speed,
                direction: uniforms.direction,
                particleType: particlePreset === "snow" ? 0 : particlePreset === "rain" ? 1 : 2,
                gyroX: gyro.x.value,
                gyroY: gyro.y.value,
              }}
            >
              <SkImage
                image={image}
                x={0}
                y={0}
                width={SCREEN_WIDTH}
                height={SCREEN_HEIGHT}
                fit="cover"
              />
            </Shader>
          </Fill>
        )}
      </Canvas>

      {/* Top bar overlay */}
      <Animated.View
        entering={FadeIn.delay(200).duration(300)}
        style={[styles.topBar, { top: insets.top + 8 }]}
      >
        <Pressable onPress={() => router.back()} style={styles.iconButton}>
          <ArrowLeft size={20} color={colors.text.primary} weight="light" />
        </Pressable>

        <Pressable onPress={handleSaveOnly} style={styles.iconButton}>
          <Check size={20} color={colors.text.primary} weight="light" />
        </Pressable>
      </Animated.View>

      {/* Bottom sheet with controls */}
      <GlassBottomSheet initialState="peek">
        <ScrollView showsVerticalScrollIndicator={false}>
          {/* Animation selector */}
          <Text style={[typography.label, { marginBottom: 12 }]}>Animation</Text>
          <ScrollView
            horizontal
            showsHorizontalScrollIndicator={false}
            style={styles.animationScroll}
          >
            {AVAILABLE_ANIMATIONS.map((type) => (
              <GlassPill
                key={type}
                label={ANIMATION_META[type].label}
                selected={animation === type}
                onPress={() => setAnimation(type)}
              />
            ))}
          </ScrollView>

          {/* Particle preset selector (only for particles animation) */}
          {animation === "particles" && (
            <>
              <Text style={[typography.label, { marginBottom: 12 }]}>Style</Text>
              <ScrollView
                horizontal
                showsHorizontalScrollIndicator={false}
                style={styles.animationScroll}
              >
                {(["snow", "rain", "bokeh"] as const).map((preset) => (
                  <GlassPill
                    key={preset}
                    label={preset === "snow" ? "Neige" : preset === "rain" ? "Pluie" : "Bokeh"}
                    selected={particlePreset === preset}
                    onPress={() => setParticlePreset(preset)}
                  />
                ))}
              </ScrollView>
            </>
          )}

          {/* Uniform controls */}
          <View style={styles.controls}>
            <GlassSlider
              label="Intensité"
              value={uniforms.intensity}
              min={0}
              max={1}
              onValueChange={(v) => setUniform("intensity", v)}
            />
            <GlassSlider
              label="Vitesse"
              value={uniforms.speed}
              min={0.05}
              max={1}
              onValueChange={(v) => setUniform("speed", v)}
            />
            {(animation === "ken-burns" || animation === "glitch") && (
              <GlassSlider
                label="Direction"
                value={uniforms.direction}
                min={0}
                max={6.28}
                step={0.1}
                onValueChange={(v) => setUniform("direction", v)}
                formatValue={(v) => `${Math.round((v * 180) / Math.PI)}°`}
              />
            )}
          </View>

          {/* Export button */}
          <View style={styles.ctaContainer}>
            <GlassButton
              label={
                status === "preparing"
                  ? "Préparation..."
                  : status === "exporting"
                  ? "Export en cours..."
                  : status === "success"
                  ? "Exporté !"
                  : "Appliquer comme fond d'écran"
              }
              onPress={handleApply}
              variant="primary"
              size="lg"
              loading={status === "preparing" || status === "exporting"}
              disabled={status === "success"}
              pulse={status === "idle"}
              icon={
                status === "idle" ? (
                  <Export size={18} color={colors.text.primary} weight="light" />
                ) : undefined
              }
            />
          </View>

          <View style={{ height: 40 }} />
        </ScrollView>
      </GlassBottomSheet>
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: colors.background,
  },
  centered: {
    justifyContent: "center",
    alignItems: "center",
    paddingHorizontal: layout.screenPadding,
  },
  canvas: {
    position: "absolute",
    top: 0,
    left: 0,
    width: SCREEN_WIDTH,
    height: SCREEN_HEIGHT,
  },
  topBar: {
    position: "absolute",
    left: 16,
    right: 16,
    flexDirection: "row",
    justifyContent: "space-between",
    zIndex: 10,
  },
  iconButton: {
    width: 40,
    height: 40,
    borderRadius: 20,
    backgroundColor: "rgba(0, 0, 0, 0.4)",
    borderWidth: 1,
    borderColor: colors.glass.border,
    alignItems: "center",
    justifyContent: "center",
  },
  animationScroll: {
    marginBottom: spacing.lg,
  },
  controls: {
    marginBottom: spacing.lg,
  },
  ctaContainer: {
    marginTop: spacing.sm,
  },
});