import React, { useCallback, useEffect, useState } from "react";
import {
  View,
  Text,
  TextInput,
  ScrollView,
  TouchableOpacity,
  Modal,
  StyleSheet,
} from "react-native";
import Checkbox from "expo-checkbox";
import { issueConfig } from "@/constants/config";
import CloseIcon from "@/assets/icons/close.svg";
import { getLanguage } from "@/services/i18n";
import { useFocusEffect } from "expo-router";

interface Issue {
  id: number;
  name: {
    en: String;
    hi: String;
  };
}

interface IssueSelectorModalProps {
  visible: boolean;
  onClose: () => void;
  onSelect: (selectedValues: number[]) => void;
  initialSelectedValues?: number[]; // Previously saved selections
  issues: Issue[];
}

export default function IssueSelectorModal({
  visible,
  onClose,
  onSelect,
  initialSelectedValues = [],
  issues = [],
}: IssueSelectorModalProps) {
  const [selectedValues, setSelectedValues] = useState<number[]>(
    initialSelectedValues
  );
  const [search, setSearch] = useState("");

  const [lang, setLang] = useState<"en" | "hi">("en");

  const toggleValue = (id: number) => {
    setSelectedValues((prev) =>
      prev.includes(id) ? prev.filter((v) => v !== id) : [...prev, id]
    );
  };

  const filteredIssues = issues.filter((issue) =>
    issue.name[lang].toLowerCase().includes(search.toLowerCase().trim())
  );

  const clearSelection = () => setSelectedValues([]);

  const hasSelection = selectedValues.length > 0;

  const handleSelect = () => {
    if (hasSelection) {
      onSelect(selectedValues);
      onClose();
    }
  };

  const handleClose = () => {
    // Reset to initial values when closing without saving
    setSelectedValues(initialSelectedValues);
    setSearch(""); // Also clear search
    onClose();
  };

  // Reset selectedValues when modal becomes visible with new initial values
  React.useEffect(() => {
    if (visible) {
      setSelectedValues(initialSelectedValues);
      setSearch("");
    }
  }, [visible, initialSelectedValues]);

  useFocusEffect(
    useCallback(() => {
      const fetchLang = async () => {
        const selectedLang = await getLanguage();
        setLang((selectedLang as "en") || "hi");
      };

      fetchLang();
    }, []) // dependencies, can include anything that triggers refetch
  );

  return (
    <Modal visible={visible} animationType="slide">
      <View style={styles.container}>
        {/* Header */}
        <View style={styles.headerBar}>
          <Text>Select Issue</Text>
          <TouchableOpacity onPress={handleClose}>
            <CloseIcon />
          </TouchableOpacity>
        </View>
        <View style={styles.divider}></View>
        <View style={styles.header}>
          <TextInput
            placeholder="Search"
            placeholderTextColor="#939DAE"
            value={search}
            onChangeText={setSearch}
            style={styles.searchBar}
          />
        </View>

        <View style={styles.counterBar}>
          <Text
            style={styles.counterText}
          >{`${selectedValues.length}/${issues.length} Selected`}</Text>
          <TouchableOpacity onPress={clearSelection} disabled={!hasSelection}>
            <Text
              style={[
                styles.clearText,
                !hasSelection && styles.clearTextDisabled,
                selectedValues.length > 0 && { color: "#006C4D" },
              ]}
            >
              Clear
            </Text>
          </TouchableOpacity>
        </View>

        <ScrollView style={styles.scrollArea}>
          {filteredIssues.length > 0 ? (
            filteredIssues.map((issue) => (
              <TouchableOpacity
                key={issue.id}
                style={styles.itemRow}
                onPress={() => toggleValue(issue.id)}
              >
                <Checkbox
                  value={selectedValues.includes(issue.id)}
                  onValueChange={() => toggleValue(issue.id)}
                  color={
                    selectedValues.includes(issue.id) ? "#009E71" : undefined
                  }
                />
                <Text style={styles.itemLabel}>{issue.name[lang]}</Text>
              </TouchableOpacity>
            ))
          ) : issues.length === 0 ? (
            <View style={styles.emptyContainer}>
              <Text style={styles.emptyText}>No issues available</Text>
            </View>
          ) : (
            <View style={styles.emptyContainer}>
              <Text style={styles.emptyText}>
                No issues found for "{search}"
              </Text>
            </View>
          )}
        </ScrollView>

        <View style={styles.buttonsContainer}>
          <TouchableOpacity style={styles.cancelButton} onPress={onClose}>
            <Text style={styles.cancelText}>Cancel</Text>
          </TouchableOpacity>
          <TouchableOpacity
            style={[
              styles.doneButton,
              !hasSelection && styles.doneButtonDisabled,
            ]}
            onPress={handleSelect}
            disabled={!hasSelection}
          >
            <Text
              style={[
                styles.doneText,
                !hasSelection && styles.doneTextDisabled,
              ]}
            >
              Select
            </Text>
          </TouchableOpacity>
        </View>
      </View>
    </Modal>
  );
}

const styles = StyleSheet.create({
  emptyContainer: {
    padding: 20,
    alignItems: "center",
    justifyContent: "center",
  },
  emptyText: {
    fontSize: 16,
    color: "#717B8F",
    textAlign: "center",
  },
  buttonsContainer: {
    flexDirection: "row",
    justifyContent: "space-between",
    alignItems: "center",
    paddingHorizontal: 16,
    paddingVertical: 20,
    backgroundColor: "#FCFCFC",
    height: 80,
    borderTopWidth: 1,
    borderTopColor: "#E5E9F0",
  },
  headerBar: {
    flexDirection: "row",
    justifyContent: "space-between",
    alignItems: "center",
    paddingHorizontal: 16,
    paddingVertical: 12,
    backgroundColor: "#F9F9F9",
  },
  cancelButton: {
    flex: 1,
    height: 40,
    borderWidth: 1,
    borderColor: "#D8DDE7",
    backgroundColor: "#F3F5F8",
    borderRadius: 4,
    justifyContent: "center",
    alignItems: "center",
    marginRight: 8,
  },
  doneButton: {
    flex: 1,
    height: 40,
    borderRadius: 4,
    justifyContent: "center",
    alignItems: "center",
    backgroundColor: "#00875F", // primary green
    marginLeft: 8,
  },
  doneButtonDisabled: {
    backgroundColor: "#E5E9F0", // disabled gray background
  },
  doneText: {
    fontSize: 14,
    fontWeight: "600",
    color: "#FFFFFF",
  },
  doneTextDisabled: {
    color: "#ADB4BD", // disabled gray text
  },
  cancelText: {
    fontSize: 14,
    fontWeight: "600",
    color: "#252A34",
  },
  clearText: {
    fontSize: 14,
    color: "#ADB4BD",
  },
  clearTextDisabled: {
    color: "#D8DDE7", // more muted when disabled
  },
  container: { flex: 1, backgroundColor: "#fff" },
  header: {
    paddingHorizontal: 16,
    paddingVertical: 12,
    backgroundColor: "#FCFCFC",
  },
  searchBar: {
    backgroundColor: "#fff",
    borderColor: "#D8DDE6",
    borderWidth: 1,
    borderRadius: 4,
    paddingHorizontal: 12,
    height: 36,
    fontSize: 14,
    color: "#252A34",
  },
  counterBar: {
    flexDirection: "row",
    justifyContent: "space-between",
    paddingHorizontal: 20,
    paddingVertical: 12,
    backgroundColor: "#FCFCFC",
  },
  divider: {
    height: 1,
    backgroundColor: "#E5E9F0",
  },
  counterText: {
    fontSize: 14,
    color: "#555",
    fontWeight: "600",
  },
  scrollArea: { paddingHorizontal: 0, backgroundColor: "#FCFCFC" },
  category: {
    fontSize: 14,
    color: "#252A34",
    paddingVertical: 12,
    paddingHorizontal: 16,
    backgroundColor: "#F9F9F9",
  },
  itemRow: {
    flexDirection: "row",
    alignItems: "center",
    paddingVertical: 8,
    paddingHorizontal: 16,
    backgroundColor: "#FCFCFC",
  },
  itemLabel: {
    marginLeft: 12,
    fontSize: 12,
    color: "#252A34",
  },
});