import React, { useMemo, useState } from 'react';
import { View, Text, Modal, ScrollView, TouchableOpacity, Linking } from 'react-native';
import { X, ChevronDown, ChevronRight, ExternalLink, Scale } from 'lucide-react-native';
import { CREDITS, LICENSE_TEXTS, CreditEntry } from '../utils/credits';

// About + open-source credits, reachable from the settings sheet. Third-party
// data is generated from node_modules (src/utils/credits.ts + THIRD_PARTY_NOTICES.md);
// each project row links to its homepage, each license group expands to the
// full license text embedded in the app.

const APP_NAME = 'recipescamera';
const APP_VERSION = '1.2'; // keep in sync with app.json

function Group({
  license,
  entries,
}: {
  license: string;
  entries: CreditEntry[];
}) {
  const [open, setOpen] = useState(false);
  const text = LICENSE_TEXTS[license];
  return (
    <View className="rounded-xl border border-zinc-800/70 bg-black/30 overflow-hidden">
      <TouchableOpacity
        onPress={() => setOpen((v) => !v)}
        className="flex-row items-center justify-between px-3 py-2.5"
        activeOpacity={0.7}
      >
        <View className="flex-row items-center">
          <Scale size={12} color="#f59e0b" strokeWidth={1.75} />
          <Text className="text-zinc-300 font-mono text-xs font-bold tracking-widest ml-2">
            {license}
          </Text>
          <Text className="text-zinc-600 font-mono text-[10px] ml-2">
            {entries.length} {entries.length === 1 ? 'component' : 'components'}
          </Text>
        </View>
        {open ? (
          <ChevronDown size={14} color="#71717a" />
        ) : (
          <ChevronRight size={14} color="#71717a" />
        )}
      </TouchableOpacity>
      {open && (
        <View className="px-3 pb-3 space-y-2">
          {entries.map((e) => (
            <View key={e.name} className="border-t border-zinc-800/60 pt-2">
              <View className="flex-row items-start justify-between">
                <Text className="text-zinc-200 font-mono text-[11px] font-semibold flex-1 pr-2">
                  {e.name}
                </Text>
                {e.url.startsWith('http') && (
                  <TouchableOpacity
                    onPress={() => Linking.openURL(e.url)}
                    accessibilityLabel={`Open ${e.name} project page`}
                    className="flex-row items-center"
                    hitSlop={{ top: 8, bottom: 8, left: 8, right: 8 }}
                  >
                    <ExternalLink size={12} color="#f59e0b" />
                  </TouchableOpacity>
                )}
              </View>
              {e.copyright ? (
                <Text className="text-zinc-500 font-mono text-[10px] mt-0.5">{e.copyright}</Text>
              ) : null}
              <Text className="text-zinc-600 font-mono text-[10px] mt-0.5">
                {e.version}
              </Text>
            </View>
          ))}
          {text ? (
            <View className="border-t border-zinc-800/60 pt-2">
              <Text selectable className="text-zinc-500 font-mono text-[9px] leading-4">
                {text}
              </Text>
            </View>
          ) : null}
        </View>
      )}
    </View>
  );
}

export default function CreditsModal({
  visible,
  onClose,
}: {
  visible: boolean;
  onClose: () => void;
}) {
  const groups = useMemo(() => {
    const byLicense = new Map<string, CreditEntry[]>();
    for (const e of CREDITS) {
      const arr = byLicense.get(e.license) ?? [];
      arr.push(e);
      byLicense.set(e.license, arr);
    }
    // stable order: licenses as declared in LICENSE_TEXTS, then rest
    const order = Object.keys(LICENSE_TEXTS);
    const sorted = [...byLicense.keys()].sort(
      (a, b) => order.indexOf(a) - order.indexOf(b)
    );
    return sorted
      .filter((k) => byLicense.has(k))
      .map((k) => ({ license: k, entries: byLicense.get(k)! }));
  }, []);

  return (
    <Modal visible={visible} transparent animationType="fade" onRequestClose={onClose}>
      <View className="flex-1 bg-black/70 items-center justify-center px-4">
        <TouchableOpacity className="absolute inset-0" activeOpacity={1} onPress={onClose} />
        <View
          className="w-full max-w-md rounded-2xl border border-zinc-800/70 p-5"
          style={{ backgroundColor: 'rgba(8,8,10,0.97)', maxHeight: '85%' }}
        >
          <View className="flex-row items-center justify-between mb-3">
            <Text className="text-zinc-300 font-mono text-xs font-bold tracking-widest">
              ABOUT &amp; CREDITS
            </Text>
            <TouchableOpacity
              onPress={onClose}
              className="w-8 h-8 rounded-full bg-zinc-900 flex items-center justify-center"
              activeOpacity={0.7}
            >
              <X size={16} color="#ffffff" />
            </TouchableOpacity>
          </View>

          <View className="rounded-xl border border-zinc-800/70 bg-black/30 px-3 py-2.5 mb-3">
            <Text className="text-zinc-200 font-mono text-sm font-bold">{APP_NAME}</Text>
            <Text className="text-zinc-500 font-mono text-[10px] mt-0.5">
              version {APP_VERSION} · film-recipe camera (experimental)
            </Text>
            <View className="flex-row flex-wrap items-center mt-1">
              <Text className="text-zinc-400 font-mono text-[10px]">Author: Lộc Phạm</Text>
              <TouchableOpacity
                onPress={() => Linking.openURL('mailto:tranloclqd@gmail.com')}
                accessibilityLabel="Email author"
                className="flex-row items-center ml-3"
                hitSlop={{ top: 6, bottom: 6, left: 6, right: 6 }}
              >
                <Text className="text-amber-500/90 font-mono text-[10px] underline">
                  tranloclqd@gmail.com
                </Text>
              </TouchableOpacity>
            </View>
            <Text className="text-zinc-600 font-mono text-[10px] mt-1">
              © 2026 Lộc Phạm · Built with React Native + Expo; icons by Lucide;
              on-screen graphics rendered with Skia.
            </Text>
          </View>

          <ScrollView className="space-y-2" showsVerticalScrollIndicator={false}>
            {groups.map((g) => (
              <Group key={g.license} license={g.license} entries={g.entries} />
            ))}
          </ScrollView>
        </View>
      </View>
    </Modal>
  );
}