import React, { useState, useMemo } from 'react';
import { View, useWindowDimensions, type ImageSourcePropType, StyleSheet } from 'react-native';

import { PageLayout } from '@/components/bestai/layout';
import { useAuth } from '@/hooks/use-auth';
import { useBalance } from '@/hooks/use-balance';
import { useProfileData } from '@/hooks/use-profile-data';
import { createStats, deriveAvatarSource, deriveDisplayName } from '@/utils/profile-data';
import { PROFILE_THEME } from '@/theme/profile';
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 { balance } = useBalance();
  const { width } = useWindowDimensions();
  const [billingMode, setBillingMode] = useState<BillingMode>('monthly');
  const [activeTab, setActiveTab] = useState<TabKey>('all');
  const [isEditingIdentity, setIsEditingIdentity] = useState(false);
  const [editedIdentity, setEditedIdentity] = useState<{
    name?: string;
    avatar?: ImageSourcePropType;
  } | null>(null);

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

  const isSmallScreen = width < PROFILE_THEME.breakpoints.small;
  const horizontalPadding = isSmallScreen
    ? PROFILE_THEME.spacing.horizontal.small
    : PROFILE_THEME.spacing.horizontal.large;
  const avatarSize = isSmallScreen
    ? PROFILE_THEME.avatar.size.small
    : PROFILE_THEME.avatar.size.large;

  const displayNameFromUser = deriveDisplayName(user) ?? 'prairie_pufferfish_the';
  const avatarSource = deriveAvatarSource(user);
  const creditBalance = balance.remainingTokenBalance;
  const stats = createStats(user);

  const presentedDisplayName = editedIdentity?.name ?? displayNameFromUser;
  const presentedAvatar = editedIdentity?.avatar ?? avatarSource;

  const headerContainerStyle = useMemo(
    () => ({
      paddingHorizontal: horizontalPadding,
      paddingBottom: PROFILE_THEME.spacing.headerBottom,
    }),
    [horizontalPadding]
  );

  const headerComponent = useMemo(
    () => (
      <View style={headerContainerStyle}>
        <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>
    ),
    [
      headerContainerStyle,
      billingMode,
      creditBalance,
      presentedDisplayName,
      presentedAvatar,
      avatarSize,
      stats,
      activeTab,
      isTabSwitching,
    ]
  );

  if (isLoading) {
    return (
      <PageLayout backgroundColor={PROFILE_THEME.colors.background} horizontalPadding={false}>
        <ProfileLoadingState />
      </PageLayout>
    );
  }

  if (error) {
    return (
      <PageLayout backgroundColor={PROFILE_THEME.colors.background} horizontalPadding={false}>
        <ProfileErrorState onRetry={handleRefresh} />
      </PageLayout>
    );
  }

  return (
    <PageLayout backgroundColor={PROFILE_THEME.colors.background} horizontalPadding={false}>
      {isLoading && generations.length === 0 ? (
        <View style={styles.flexContainer}>
          {headerComponent}
          <ContentSkeleton />
        </View>
      ) : generations.length === 0 && !isTabSwitching ? (
        <View style={styles.flexContainer}>
          {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 }) => {
          setEditedIdentity({ name, avatar });
          setIsEditingIdentity(false);
        }}
      />
    </PageLayout>
  );
}

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

export default ProfileScreen;
