import React, { useCallback, useEffect, useRef, useState } from "react";
import { StyleSheet, Text, View } from "react-native";
import { Palette, Style } from "../styles";
import { FONT_FAMILY } from "../styles/Fonts";
import { LinearGradient } from "./LinearGradient/LinearGradient";

const INITIAL_BOX_SIZE = 6;
const HANDLE_SIZE = 20;
const HANDLE_TOP_OFFSET = (INITIAL_BOX_SIZE - HANDLE_SIZE) / 2;

const clamp01 = (value) => Math.min(1, Math.max(0, value));

const Slider = ({
  value,
  maxValue,
  progress,
  onSeek,
  onSeekStart,
  onSeekEnd,
  seekEnabled = false,
}) => {
  const [layoutWidth, setLayoutWidth] = useState(0);
  const [ratio, setRatio] = useState(
    typeof progress === "number" ? clamp01(progress) : 0,
  );
  const draggingRef = useRef(false);

  useEffect(() => {
    if (!draggingRef.current && typeof progress === "number") {
      setRatio(clamp01(progress));
    }
  }, [progress]);

  const updateRatioFromX = useCallback(
    (x) => {
      if (layoutWidth <= 0) return;
      const available = Math.max(layoutWidth - INITIAL_BOX_SIZE, 0);
      if (available <= 0) {
        setRatio(0);
        return;
      }
      const clampedX = Math.min(Math.max(x, 0), layoutWidth);
      const nextRatio = clamp01(clampedX / available);
      setRatio(nextRatio);
    },
    [layoutWidth],
  );

  const handleGrant = useCallback(
    (event) => {
      if (!seekEnabled) return;
      draggingRef.current = true;
      updateRatioFromX(event?.nativeEvent?.locationX || 0);
      if (typeof onSeekStart === "function") {
        onSeekStart();
      }
    },
    [seekEnabled, updateRatioFromX, onSeekStart],
  );

  const handleMove = useCallback(
    (event) => {
      if (!seekEnabled || !draggingRef.current) return;
      updateRatioFromX(event?.nativeEvent?.locationX || 0);
    },
    [seekEnabled, updateRatioFromX],
  );

  const finishSeeking = useCallback(() => {
    if (!seekEnabled || !draggingRef.current) return;
    draggingRef.current = false;
    const currentRatio = clamp01(ratio);
    if (typeof onSeek === "function") {
      onSeek(currentRatio);
    }
    if (typeof onSeekEnd === "function") {
      onSeekEnd();
    }
  }, [seekEnabled, ratio, onSeek, onSeekEnd]);

  const handleLayout = useCallback((event) => {
    const width = event?.nativeEvent?.layout?.width || 0;
    if (width !== layoutWidth) {
      setLayoutWidth(width);
    }
  }, [layoutWidth]);

  const maxOffset = Math.max(layoutWidth - INITIAL_BOX_SIZE, 0);
  const offset = maxOffset * ratio;

  return (
    <View style={styles.container}>
      <View
        style={[
          styles.interactionArea,
          seekEnabled ? styles.pointerEnabled : null,
        ]}
        onLayout={handleLayout}
        onStartShouldSetResponderCapture={() => seekEnabled}
        onStartShouldSetResponder={() => seekEnabled}
        onMoveShouldSetResponder={() => seekEnabled}
        onResponderGrant={handleGrant}
        onResponderMove={handleMove}
        onResponderRelease={finishSeeking}
        onResponderTerminate={finishSeeking}
      >
        <View style={styles.sliderTrack}>
          <View style={[styles.box, { width: INITIAL_BOX_SIZE + offset }]}>
            <LinearGradient
              colors={["#F94697", "#7023F7"]}
              start={{ x: 0, y: 0 }}
              end={{ x: 1, y: 0 }}
              style={{ flex: 1, borderRadius: 20 }}
            />
          </View>
        </View>
        <View style={[styles.sliderHandle, { left: offset }]} />
      </View>
      <View style={{ ...Style.containerSpaceBetween, marginTop: 10 }}>
        <Text style={styles.time}>{value}</Text>
        <Text style={styles.time}>{maxValue}</Text>
      </View>
    </View>
  );
};

const styles = StyleSheet.create({
  container: {
    width: "100%",
  },
  interactionArea: {
    width: "100%",
    height: HANDLE_SIZE,
    justifyContent: "center",
    position: "relative",
  },
  pointerEnabled: {
    cursor: "pointer",
  },
  sliderTrack: {
    width: "100%",
    height: INITIAL_BOX_SIZE,
    backgroundColor: "#0F0C19",
    borderRadius: 25,
    overflow: "hidden",
  },
  box: {
    height: INITIAL_BOX_SIZE,
    borderRadius: 20,
    position: "absolute",
    left: 0,
    top: 0,
    zIndex: 1,
    overflow: "hidden",
  },
  sliderHandle: {
    width: HANDLE_SIZE,
    height: HANDLE_SIZE,
    backgroundColor: "#f8f9ff",
    borderRadius: HANDLE_SIZE / 2,
    position: "absolute",
    top: HANDLE_TOP_OFFSET,
    zIndex: 2,
    borderWidth: 4,
    borderColor: "#9B4DFF",
    shadowColor: "#8951FC",
    shadowOffset: {
      width: 0,
      height: 3,
    },
    shadowOpacity: 0.17,
    shadowRadius: 3.05,
    elevation: 4,
  },
  time: {
    fontSize: 14,
    color: Palette.white,
    fontFamily: FONT_FAMILY.InterRegular,
  },
});

export default Slider;