import React, { useCallback, useMemo } from "react";
import {
  FlatList,
  Image,
  StyleSheet,
  Text,
  View,
  useWindowDimensions,
} from "react-native";
import { BlurView } from "expo-blur";
import Page from "../../layouts/Page";
import { background, img } from "../../assets";
import { Palette } from "../../styles";
import { FONT_FAMILY } from "../../styles/Fonts";
import { navigate } from "../../navigation/NavigationService";
import { Routes } from "../../navigation";
import { useUser } from "../../providers/UserDataProvider";
import ProjectDropDown from "../../components/ProjectDropDown/ProjectDropDown";

const ITEM_SPACING = 24;

const Home = () => {
  const {
    userProjects = [],
    resetSelectedProject,
    selectProject,
    selectedProject,
    selectedProjectId,
  } = useUser();

  const projects = useMemo(
    () => (Array.isArray(userProjects) ? userProjects : []),
    [userProjects],
  );

  const { width: windowWidth } = useWindowDimensions();

  const carouselItems = useMemo(
    () => [
      {
        id: "project-vision",
        title: "Composez sans limites",
        description:
          "Créez instantanément des maquettes professionnelles et explorez de nouveaux genres.",
        image: img.placeholder,
      },
      {
        id: "project-community",
        title: "Collaborez en équipe",
        description:
          "Partagez vos projets, échangez des idées et co-créez en temps réel.",
        image: img.placeholder2,
      },
      {
        id: "project-ai",
        title: "Optimisé par l'IA",
        description:
          "Accédez à des suggestions intelligentes pour les paroles, arrangements et mixages.",
        image: img.placeholder3,
      },
      {
        id: "project-stage",
        title: "Prêt pour la scène",
        description:
          "Finalisez vos titres et exportez-les facilement pour le live ou le streaming.",
        image: img.placeholder4,
      },
    ],
    [],
  );

  const carouselItemWidth = useMemo(() => {
    const baseWidth = Math.min(windowWidth * 0.9, 640);
    return Math.max(baseWidth, 320);
  }, [windowWidth]);

  const carouselItemHeight = useMemo(() => {
    const baseHeight = Math.min(windowWidth * 0.6, 360);
    return Math.max(baseHeight, 240);
  }, [windowWidth]);

  const snapInterval = useMemo(
    () => carouselItemHeight + ITEM_SPACING,
    [carouselItemHeight],
  );

  const currentProject = useMemo(() => {
    if (!projects.length) return null;
    const activeId = selectedProject?.id || selectedProjectId;
    if (!activeId) {
      return projects[0];
    }
    return projects.find((project) => project?.id === activeId) || projects[0];
  }, [projects, selectedProject?.id, selectedProjectId]);

  const formatDate = useCallback((timestamp) => {
    try {
      const value = timestamp?.toDate ? timestamp.toDate() : timestamp;
      const date = value ? new Date(value) : null;
      if (!date || Number.isNaN(date.getTime())) {
        return "";
      }
      const day = date.getDate().toString().padStart(2, "0");
      const month = (date.getMonth() + 1).toString().padStart(2, "0");
      return `${day}/${month}`;
    } catch (error) {
      console.warn("Home.web: formatDate error", error);
      return "";
    }
  }, []);

  const handleSelectProject = (project) => {
    if (!project?.id) return;
    selectProject(project.id);
  };

  const handleModifyProject = (project) => {
    if (!project?.id) return;
    selectProject(project.id);
    navigate(Routes.FlowSelection);
  };

  const handleCreateNew = () => {
    resetSelectedProject();
    navigate(Routes.FlowSelection);
  };

  const renderCarouselItem = useCallback(
    ({ item, index }) => {
      const isImageOnRight = index % 2 === 1;

      let imageSize = Math.min(carouselItemHeight - 24, 280);
      let availableWidth = carouselItemWidth - imageSize - 48;

      if (availableWidth < 140) {
        const minImageSize = Math.max(carouselItemWidth - 140 - 48, 140);
        imageSize = Math.min(imageSize, minImageSize);
        availableWidth = carouselItemWidth - imageSize - 48;
      }

      const blurWidth = Math.min(Math.max(availableWidth, 120), 260);
      const blurHeight = Math.max(
        Math.min(imageSize * 0.75, carouselItemHeight - 48),
        140,
      );

      return (
        <View
          style={[
            { width: carouselItemWidth, height: carouselItemHeight },
            isImageOnRight ? styles.carouselItemRight : styles.carouselItemLeft,
          ]}
        >
          <Image
            source={item.image}
            style={[
              styles.carouselImage,
              { width: imageSize, height: imageSize },
              isImageOnRight
                ? styles.carouselImageRight
                : styles.carouselImageLeft,
            ]}
            resizeMode="cover"
          />
          <BlurView
            intensity={30}
            tint="dark"
            style={[
              styles.carouselBlur,
              { width: blurWidth, height: blurHeight },
              isImageOnRight
                ? styles.carouselBlurRight
                : styles.carouselBlurLeft,
            ]}
          >
            <View style={styles.carouselTextContainer}>
              <Text style={styles.carouselTitle}>{item.title}</Text>
              <Text style={styles.carouselDescription}>{item.description}</Text>
            </View>
          </BlurView>
        </View>
      );
    },
    [carouselItemHeight, carouselItemWidth],
  );

  const keyExtractor = useCallback((item) => item.id, []);

  return (
    <Page shareBtn backgroundImg={background.homeBGWeb} headerType="NONE">
      <View style={styles.root}>
        <View style={styles.dropdownArea}>
          <ProjectDropDown
            style={styles.dropdownContainer}
            projects={projects}
            selectedProject={currentProject}
            onSelectProject={handleSelectProject}
            onModifyProject={handleModifyProject}
            onCreateProject={handleCreateNew}
            formatDate={formatDate}
          />
        </View>
        <View style={styles.carouselSection}>
          <FlatList
            data={carouselItems}
            keyExtractor={keyExtractor}
            renderItem={renderCarouselItem}
            showsVerticalScrollIndicator={false}
            snapToInterval={snapInterval}
            snapToAlignment="start"
            decelerationRate="fast"
            disableIntervalMomentum={true}
            pagingEnabled
            style={[styles.carouselList, { height: carouselItemHeight }]}
            contentContainerStyle={{
              paddingVertical: ITEM_SPACING / 2,
              alignItems: "center",
            }}
            ItemSeparatorComponent={() => (
              <View style={{ height: ITEM_SPACING }} />
            )}
          />
        </View>
      </View>
    </Page>
  );
};

export default Home;

const styles = StyleSheet.create({
  root: {
    flex: 1,
    paddingHorizontal: 24,
    position: "relative",
    justifyContent: "flex-start",
    alignItems: "center",
    width: "100%",
  },
  heroImage: {
    position: "absolute",
    top: -60,
    alignSelf: "center",
    width: "80%",
    maxWidth: 920,
    height: 420,
    opacity: 0.9,
  },
  dropdownArea: {
    width: "100%",
    alignItems: "center",
    justifyContent: "center",
    paddingTop: 72,
    zIndex: 2,
  },
  dropdownContainer: {
    width: "100%",
  },
  shareIcon: {
    width: 18,
    height: 18,
    tintColor: Palette.white,
  },
  carouselSection: {
    width: "100%",
    marginTop: 48,
  },
  carouselList: {
    width: "100%",
  },
  carouselItem: {
    borderRadius: 18,
    backgroundColor: "rgba(0, 0, 0, 0.18)",
    borderWidth: 1,
    borderColor: "rgba(255, 255, 255, 0.1)",
    paddingVertical: 24,
    paddingHorizontal: 16,
    alignItems: "center",
    justifyContent: "center",
  },
  carouselItemRight: {
    flexDirection: "row-reverse",
    alignItems: "center",
  },
  carouselItemLeft: {
    flexDirection: "row",
    alignItems: "center",
  },
  carouselImage: {
    borderRadius: 28,
    shadowColor: "#000",
    shadowOffset: { width: 0, height: 8 },
    shadowOpacity: 0.25,
    shadowRadius: 20,
  },
  carouselImageRight: {
    marginLeft: 20,
  },
  carouselImageLeft: {
    marginRight: 20,
  },
  carouselBlur: {
    borderRadius: 20,
    overflow: "hidden",
    paddingHorizontal: 18,
    paddingVertical: 16,
    justifyContent: "center",
    alignItems: "flex-start",
    backgroundColor: "rgba(0, 0, 0, 0.25)",
    gap: 8,
  },
  carouselBlurRight: {
    marginRight: 12,
  },
  carouselBlurLeft: {
    marginLeft: 12,
  },
  carouselTextContainer: {
    width: "100%",
  },
  carouselTitle: {
    fontSize: 20,
    color: Palette.white,
    fontFamily: FONT_FAMILY.InterSemiBold,
    marginBottom: 8,
  },
  carouselDescription: {
    fontSize: 14,
    lineHeight: 20,
    color: "rgba(255, 255, 255, 0.7)",
    fontFamily: FONT_FAMILY.InterRegular,
  },
});