import React, { useState } from 'react';
import { View, Text, TouchableOpacity, TextInput, Modal, KeyboardAvoidingView, Platform, Alert } from 'react-native';
import { useSafeAreaInsets } from 'react-native-safe-area-context';
import { Plus, Pencil, Undo2, Zap, ZapOff } from 'lucide-react-native';
import * as Haptics from 'expo-haptics';

import type { FlashMode } from '../types';

// "A" badge tucked into the corner of the flash button's AUTO state.
const FLASH_A_BADGE = {
  position: 'absolute' as const,
  bottom: 3,
  right: 5,
  fontSize: 8,
  fontWeight: '700' as const,
  color: '#f4f4f5',
};

interface TopBarProps {
  mode: 'camera' | 'library';
  recipeName: string;
  onSaveRecipe: (name: string) => void;
  // Present only when the active recipe is user-created: enables Save (overwrite).
  onOverwriteRecipe?: (name: string) => void;
  // Also custom-only: opens the recipe editor — the CREATE form prefilled
  // with this recipe's parameters and name.
  onEditRecipe?: () => void;
  // SAVE & SHARE -> EXPORT: write this look to an encrypted recipe file and
  // hand it to the system share sheet so it can reach another phone.
  onExportShare: (name: string) => void;
  // BACK (undo): one step back through the look's history. PRO only — App
  // refuses and offers the paywall when a LITE build taps it. No count is
  // drawn: the icon turns amber while there is a step to go back to.
  onUndo: () => void;
  undoDepth: number;
  // LED flash state for the next still, cycled off -> auto -> on. Absent =
  // no flash control to show (library mode, or a lens with no flash unit),
  // so the front camera shows no dead control.
  flashMode?: FlashMode;
  onCycleFlash?: () => void;
  // Height of the floating top strip (its own onLayout): App keeps the library
  // photo — and with it the ratio band — out from under it.
  onHeight?: (height: number) => void;
}

export default function TopBar({
  mode,
  recipeName,
  onSaveRecipe,
  onOverwriteRecipe,
  onEditRecipe,
  onExportShare,
  onUndo,
  undoDepth,
  flashMode,
  onCycleFlash,
  onHeight,
}: TopBarProps) {
  const insets = useSafeAreaInsets();
  const [modalVisible, setModalVisible] = useState(false);
  const [newRecipeName, setNewRecipeName] = useState('');

  const openModal = () => {
    // Bundled recipes are read-only -> Save As only, blank name. Custom ones
    // prefill with the current name so Save (overwrite) is one tap.
    setNewRecipeName(onOverwriteRecipe ? recipeName : '');
    setModalVisible(true);
  };

  // SAVE & SHARE: two ways out of the same look — keep it as a recipe on this
  // phone, or export it as a file another phone can import.
  const openSaveMenu = () => {
    Alert.alert(
      'SAVE & SHARE',
      'Save the look on this screen as a recipe, or export it as a file to share.',
      [
        { text: 'CANCEL', style: 'cancel' },
        { text: 'EXPORT & SHARE', onPress: () => onExportShare(recipeName) },
        { text: 'SAVE RECIPE', onPress: openModal },
      ],
    );
  };

  const run = (fn: (name: string) => void) => {
    const name = newRecipeName.trim();
    if (!name) return;
    fn(name);
    setNewRecipeName('');
    setModalVisible(false);
    Haptics.impactAsync(Haptics.ImpactFeedbackStyle.Light);
  };

  const handleSavePress = () => run(onSaveRecipe);
  const handleOverwritePress = () => onOverwriteRecipe && run(onOverwriteRecipe);

  return (
    <>
      <View
        style={{ paddingTop: insets.top + 6 }}
        onLayout={(e) => onHeight?.(e.nativeEvent.layout.height)}
        className="absolute top-0 left-0 right-0 z-20 flex-row items-start justify-between px-4"
      >
        <View className="max-w-[62%] rounded-xl border border-zinc-800/80 bg-black/45 px-3 py-2">
          <Text className="text-amber-500 font-mono text-[9px] font-bold tracking-[0.2em]">
            {mode === 'camera' ? 'LIVE' : 'LIBRARY'}
          </Text>
          <Text
            numberOfLines={1}
            className="text-white font-mono text-sm font-bold tracking-wide"
          >
            {recipeName}
          </Text>
        </View>

        <View className="flex-row items-center space-x-2">
          {/* Capture-time LED flash, left of BACK: a still taken on the 0.5x
              native lens goes through its own Camera2 request, so the state
              has to be reachable while the chip row is off screen. */}
          {flashMode && onCycleFlash ? (
            <TouchableOpacity
              onPress={onCycleFlash}
              accessibilityRole="button"
              accessibilityLabel={`Flash ${flashMode}`}
              accessibilityHint="Cycles flash off, auto and on"
              className="rounded-full border border-zinc-700/80 bg-black/45 p-2.5"
              activeOpacity={0.7}
            >
              {flashMode === 'off' ? (
                <ZapOff size={13} color="#e4e4e7" />
              ) : (
                // AUTO keeps the bolt dim and adds the badge below — a lit
                // bolt alone would read as ON.
                <Zap size={13} color={flashMode === 'on' ? '#fbbf24' : '#e4e4e7'} />
              )}
              {flashMode === 'auto' ? <Text style={FLASH_A_BADGE}>A</Text> : null}
            </TouchableOpacity>
          ) : null}
          {/* BACK: the history control the chip row used to carry, sitting
              between the status block and SAVE & SHARE. Lucide (ISC) vector
              — no icon font to ship or license. */}
          <TouchableOpacity
            onPress={onUndo}
            accessibilityLabel="BACK"
            className="rounded-full border border-zinc-700/80 bg-black/45 p-2.5"
            activeOpacity={0.7}
          >
            <Undo2 size={13} color={undoDepth > 0 ? '#f59e0b' : '#52525b'} />
          </TouchableOpacity>
          {onEditRecipe && (
            <TouchableOpacity
              onPress={onEditRecipe}
              className="rounded-full border border-zinc-700/80 bg-black/45 p-2.5"
              activeOpacity={0.7}
            >
              <Pencil size={13} color="#f59e0b" />
            </TouchableOpacity>
          )}
          <TouchableOpacity
            onPress={openSaveMenu}
            className="flex-row items-center rounded-full border border-zinc-700/80 bg-black/45 px-3 py-2.5"
            activeOpacity={0.7}
          >
            <Plus size={14} color="#f59e0b" />
            <Text className="ml-1 font-mono text-[10px] font-bold tracking-wider text-amber-500">
              SAVE & SHARE
            </Text>
          </TouchableOpacity>
        </View>
      </View>

      <Modal
        transparent
        animationType="slide"
        visible={modalVisible}
        onRequestClose={() => setModalVisible(false)}
      >
        <View className="absolute inset-0 bg-black/60" />
        <KeyboardAvoidingView
          style={{ flex: 1 }}
          behavior={Platform.OS === 'ios' ? 'padding' : 'height'}
        >
          <View style={{ paddingBottom: insets.bottom + 16 }} className="mt-auto bg-titan border-t border-zinc-800 rounded-t-3xl p-6">
            <Text className="text-white font-mono text-sm font-bold tracking-wider mb-4">
              {onOverwriteRecipe ? 'SAVE RECIPE' : 'SAVE CURRENT AS RECIPE'}
            </Text>
            <TextInput
              value={newRecipeName}
              onChangeText={setNewRecipeName}
              placeholder="Recipe name (e.g. Retro Film)"
              placeholderTextColor="#71717a"
              className="bg-carbon border border-zinc-800 rounded-lg p-3 text-white font-mono text-sm mb-4"
              autoFocus
              onSubmitEditing={handleSavePress}
            />
            <View className="flex-row space-x-3">
              <TouchableOpacity
                onPress={() => setModalVisible(false)}
                className="flex-1 bg-zinc-800 py-3 rounded-lg items-center"
              >
                <Text className="text-zinc-300 font-mono text-xs font-semibold">CANCEL</Text>
              </TouchableOpacity>
              {onOverwriteRecipe ? (
                <>
                  <TouchableOpacity
                    onPress={handleSavePress}
                    className="flex-1 border border-amber-500 py-3 rounded-lg items-center"
                  >
                    <Text className="text-amber-500 font-mono text-xs font-bold">SAVE AS</Text>
                  </TouchableOpacity>
                  <TouchableOpacity
                    onPress={handleOverwritePress}
                    className="flex-1 bg-amber-500 py-3 rounded-lg items-center"
                  >
                    <Text className="text-black font-mono text-xs font-bold">SAVE</Text>
                  </TouchableOpacity>
                </>
              ) : (
                <TouchableOpacity
                  onPress={handleSavePress}
                  className="flex-1 bg-amber-500 py-3 rounded-lg items-center"
                >
                  <Text className="text-black font-mono text-xs font-bold">SAVE RECIPE</Text>
                </TouchableOpacity>
              )}
            </View>
          </View>
        </KeyboardAvoidingView>
      </Modal>
    </>
  );
}