import React, { useEffect, useState, useMemo } from 'react';
import { View, useWindowDimensions, type ImageSourcePropType, ActivityIndicator } from 'react-native';
import { useSafeAreaInsets } from 'react-native-safe-area-context';

import { useAuth } from '@/hooks/use-auth';
import { useProfileData } from '@/hooks/use-profile-data';
import { createStats, deriveAvatarSource, deriveDisplayName, deriveNumericValue } from '@/utils/profile-data';
import { StyleSheet } from 'react-native';
import { ContentGallery } from './content-gallery';
import { ContentTabs } from './content-tabs';
import { Divider } from './divider';
import { ProfileEditModal } from './profile-edit-modal';
import { ProfileEmptyState } from './profile-empty-state';
import { ProfileErrorState } from './profile-error-state';
import { ProfileHeader } from './profile-header';
import { ProfileIdentity } from './profile-identity';
import { ProfileLoadingState } from './profile-loading-state';
import { ContentSkeleton } from './content-skeleton';

type TabKey = 'all' | 'image' | 'video';
type BillingMode = 'monthly' | 'lifetime';

export function ProfileScreen() {
  const { user } = useAuth();
  const { width } = useWindowDimensions();
  const insets = useSafeAreaInsets();
  const [billingMode, setBillingMode] = useState<BillingMode>('monthly');
  const [activeTab, setActiveTab] = useState<TabKey>('all');
  const displayNameFromUser = deriveDisplayName(user) ?? 'prairie_pufferfish_the';
  const [presentedDisplayName, setPresentedDisplayName] = useState(displayNameFromUser);
  const [isEditingIdentity, setIsEditingIdentity] = useState(false);

  const {
    generations,
    isLoading,
    error,
    isRefreshing,
    isLoadingMore,
    hasMore,
    isTabSwitching,
    handleRefresh,
    handleLoadMore,
  } = useProfileData(activeTab);

  const horizontalPadding = width < 400 ? 20 : 24;
  const avatarSize = width < 400 ? 74 : 82;
  const avatarSource = deriveAvatarSource(user);
  const creditBalance = deriveNumericValue((user as Record<string, unknown>)?.credits);
  const stats = createStats(user);
  const [presentedAvatar, setPresentedAvatar] = useState<ImageSourcePropType | undefined>(avatarSource);

  useEffect(() => {
    setPresentedDisplayName(displayNameFromUser);
  }, [displayNameFromUser]);

  useEffect(() => {
    setPresentedAvatar(avatarSource);
  }, [avatarSource]);

  const headerComponent = useMemo(
    () => (
      <View style={{ paddingHorizontal: horizontalPadding, paddingBottom: 16 }}>
        <ProfileHeader
          billingMode={billingMode}
          onChangeBilling={setBillingMode}
          credits={creditBalance}
        />

        <ProfileIdentity
          displayName={presentedDisplayName}
          avatarSource={presentedAvatar}
          avatarSize={avatarSize}
          stats={stats}
          onEdit={() => setIsEditingIdentity(true)}
        />

        <Divider />

        <ContentTabs
          activeTab={activeTab}
          onChangeTab={setActiveTab}
          isLoading={isTabSwitching}
        />

        <Divider />
      </View>
    ),
    [
      horizontalPadding,
      billingMode,
      creditBalance,
      presentedDisplayName,
      presentedAvatar,
      avatarSize,
      stats,
      activeTab,
      isTabSwitching,
    ]
  );

  if (isLoading) {
    return (
      <View style={[styles.screen, { backgroundColor: stylesVars.background }]}>
        {insets.top > 0 && <View style={{ height: insets.top }} />}
        <ProfileLoadingState />
      </View>
    );
  }

  if (error) {
    return (
      <View style={[styles.screen, { backgroundColor: stylesVars.background }]}>
        {insets.top > 0 && <View style={{ height: insets.top }} />}
        <ProfileErrorState onRetry={handleRefresh} />
      </View>
    );
  }

  return (
    <View style={[styles.screen, { backgroundColor: stylesVars.background }]}>
      {insets.top > 0 && <View style={{ height: insets.top }} />}

      {isLoading && generations.length === 0 ? (
        <View style={{ flex: 1 }}>
          {headerComponent}
          <ContentSkeleton />
        </View>
      ) : generations.length === 0 && !isTabSwitching ? (
        <View style={{ flex: 1 }}>
          {headerComponent}
          <ProfileEmptyState activeTab={activeTab} />
        </View>
      ) : (
        <ContentGallery
          generations={generations}
          isRefreshing={isRefreshing}
          onRefresh={handleRefresh}
          isLoadingMore={isLoadingMore}
          hasMore={hasMore}
          onLoadMore={handleLoadMore}
          ListHeaderComponent={headerComponent}
        />
      )}

      <ProfileEditModal
        visible={isEditingIdentity}
        avatarSource={presentedAvatar}
        initialName={presentedDisplayName}
        onClose={() => setIsEditingIdentity(false)}
        onSave={({ name, avatar }) => {
          setPresentedDisplayName(name);
          if (avatar) {
            setPresentedAvatar(avatar);
          }
          setIsEditingIdentity(false);
        }}
      />
    </View>
  );
}

const stylesVars = {
  background: '#050505',
  paddingBottom: 96,
};

const styles = StyleSheet.create({
  screen: {
    flex: 1,
  },
});

export default ProfileScreen;