import 'package:flutter/material.dart';
import 'package:google_fonts/google_fonts.dart';
import 'package:trainhub_flutter/core/constants/ui_constants.dart';
import 'package:trainhub_flutter/core/theme/app_colors.dart';
import 'package:trainhub_flutter/presentation/welcome/widgets/welcome_buttons.dart';

class InitialPrompt extends StatelessWidget {
  const InitialPrompt({
    super.key,
    required this.onDownload,
    required this.onSkip,
  });

  final VoidCallback onDownload;
  final VoidCallback onSkip;

  @override
  Widget build(BuildContext context) {
    return Column(
      mainAxisAlignment: MainAxisAlignment.center,
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        _buildLogoRow(),
        const SizedBox(height: UIConstants.spacing32),
        _buildHeadline(),
        const SizedBox(height: UIConstants.spacing16),
        _buildDescription(),
        const SizedBox(height: UIConstants.spacing24),
        _buildFeatureList(),
        const SizedBox(height: UIConstants.spacing32),
        _buildDownloadNotice(),
        const SizedBox(height: UIConstants.spacing32),
        _buildActionButtons(),
      ],
    );
  }

  Widget _buildLogoRow() {
    return Row(
      children: [
        Container(
          width: 48,
          height: 48,
          decoration: BoxDecoration(
            color: AppColors.accentMuted,
            borderRadius: BorderRadius.circular(12),
          ),
          child: const Icon(
            Icons.fitness_center,
            color: AppColors.accent,
            size: 24,
          ),
        ),
        const SizedBox(width: UIConstants.spacing12),
        Text(
          'TrainHub',
          style: GoogleFonts.inter(
            fontSize: 26,
            fontWeight: FontWeight.w700,
            color: AppColors.textPrimary,
            letterSpacing: -0.5,
          ),
        ),
      ],
    );
  }

  Widget _buildHeadline() {
    return Text(
      'AI-powered coaching,\nright on your device.',
      style: GoogleFonts.inter(
        fontSize: 28,
        fontWeight: FontWeight.w700,
        color: AppColors.textPrimary,
        height: 1.25,
        letterSpacing: -0.5,
      ),
    );
  }

  Widget _buildDescription() {
    return Text(
      'TrainHub uses on-device AI models to give you intelligent '
      'training advice, exercise analysis, and personalised chat — '
      'with zero data sent to the cloud.',
      style: GoogleFonts.inter(
        fontSize: 14,
        color: AppColors.textSecondary,
        height: 1.6,
      ),
    );
  }

  Widget _buildFeatureList() {
    return const Column(
      children: [
        FeatureRow(
          icon: Icons.lock_outline_rounded,
          label: '100 % local — your data never leaves this machine.',
        ),
        SizedBox(height: UIConstants.spacing12),
        FeatureRow(
          icon: Icons.psychology_outlined,
          label: 'Qwen 2.5 7B chat model for training advice.',
        ),
        SizedBox(height: UIConstants.spacing12),
        FeatureRow(
          icon: Icons.search_rounded,
          label: 'Nomic embedding model for semantic exercise search.',
        ),
      ],
    );
  }

  Widget _buildDownloadNotice() {
    return Container(
      padding: const EdgeInsets.symmetric(
        horizontal: UIConstants.spacing16,
        vertical: UIConstants.spacing12,
      ),
      decoration: BoxDecoration(
        color: AppColors.accentMuted,
        borderRadius: BorderRadius.circular(UIConstants.smallBorderRadius),
        border: Border.all(
          color: AppColors.accent.withValues(alpha: 0.3),
        ),
      ),
      child: Row(
        children: [
          const Icon(
            Icons.download_outlined,
            color: AppColors.accent,
            size: 18,
          ),
          const SizedBox(width: UIConstants.spacing12),
          Expanded(
            child: Text(
              'The download is ~5 GB and only needs to happen once. '
              'You can skip now and download later from Settings.',
              style: GoogleFonts.inter(
                fontSize: 13,
                color: AppColors.accent,
                height: 1.5,
              ),
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildActionButtons() {
    return Row(
      children: [
        Expanded(
          child: WelcomePrimaryButton(
            label: 'Download Now',
            icon: Icons.download_rounded,
            onPressed: onDownload,
          ),
        ),
        const SizedBox(width: UIConstants.spacing12),
        Expanded(
          child: WelcomeSecondaryButton(
            label: 'Skip for Now',
            onPressed: onSkip,
          ),
        ),
      ],
    );
  }
}

class FeatureRow extends StatelessWidget {
  const FeatureRow({super.key, required this.icon, required this.label});

  final IconData icon;
  final String label;

  @override
  Widget build(BuildContext context) {
    return Row(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Container(
          width: 28,
          height: 28,
          decoration: BoxDecoration(
            color: AppColors.surfaceContainerHigh,
            borderRadius: BorderRadius.circular(6),
          ),
          child: Icon(icon, size: 14, color: AppColors.accent),
        ),
        const SizedBox(width: UIConstants.spacing12),
        Expanded(
          child: Text(
            label,
            style: GoogleFonts.inter(
              fontSize: 13,
              color: AppColors.textSecondary,
              height: 1.5,
            ),
          ),
        ),
      ],
    );
  }
}