import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:flutter_lucide/flutter_lucide.dart';
import 'package:get/get.dart';
import 'package:on_field_work/controller/dashboard/dashboard_controller.dart';
import 'package:on_field_work/helpers/services/gemini_service.dart';
import 'package:on_field_work/helpers/utils/mixins/ui_mixin.dart';
import 'package:on_field_work/helpers/widgets/my_spacing.dart';
import 'package:on_field_work/helpers/widgets/my_text.dart';

/// Floating Gemini assistant for mobile dashboard.
/// Shows a circular FAB, which expands into a small chat panel from bottom-right.
class GeminiFloatingAssistant extends StatefulWidget {
  final DashboardController dashboardController;

  const GeminiFloatingAssistant({
    super.key,
    required this.dashboardController,
  });

  @override
  State<GeminiFloatingAssistant> createState() =>
      _GeminiFloatingAssistantState();
}

class _GeminiFloatingAssistantState extends State<GeminiFloatingAssistant>
    with SingleTickerProviderStateMixin, UIMixin {
  // State
  final TextEditingController _promptController = TextEditingController();
  final RxList<Map<String, String>> _chatHistory =
      <Map<String, String>>[].obs;
  final RxBool _isLoading = false.obs;
  final RxBool _isAnalyzingData = false.obs;
  final RxString _error = ''.obs;
  final RxBool _isOpen = false.obs;

  final ScrollController _scrollController = ScrollController();

  late final AnimationController _animController;
  late final Animation<double> _scaleAnimation;
  late final Animation<double> _opacityAnimation;

  @override
  void initState() {
    super.initState();
    _animController = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 280),
    );
    _scaleAnimation = CurvedAnimation(
      parent: _animController,
      curve: Curves.fastOutSlowIn,
    );
    _opacityAnimation = CurvedAnimation(
      parent: _animController,
      curve: Curves.easeInOut,
    );
  }

  // Scroll helper
  void _scrollToBottom() {
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (_scrollController.hasClients) {
        _scrollController.animateTo(
          _scrollController.position.maxScrollExtent,
          duration: const Duration(milliseconds: 250),
          curve: Curves.easeOut,
        );
      }
    });
  }

  // Toggle FAB / panel
  void _toggleOpen() {
    _error.value = '';
    final newValue = !_isOpen.value;
    _isOpen.value = newValue;
    if (newValue) {
      _animController.forward();
    } else {
      _animController.reverse();
    }
  }

  // Chat bubble
  Widget _buildResponseBubble(String text, bool isAI) {
    if (text.isEmpty) return const SizedBox.shrink();

    final Color backgroundColor =
        isAI ? Colors.blue.shade50 : contentTheme.primary.withOpacity(0.9);
    final Color textColor = isAI ? Colors.black87 : Colors.white;

    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 4),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        mainAxisAlignment:
            isAI ? MainAxisAlignment.start : MainAxisAlignment.end,
        children: [
          if (isAI) ...[
            const Icon(LucideIcons.bot, color: Colors.blue, size: 20),
            MySpacing.width(8),
          ],
          Flexible(
            child: Container(
              padding: const EdgeInsets.all(10),
              decoration: BoxDecoration(
                color: backgroundColor,
                borderRadius: BorderRadius.only(
                  topLeft: const Radius.circular(14),
                  topRight: const Radius.circular(14),
                  bottomLeft:
                      isAI ? Radius.zero : const Radius.circular(14),
                  bottomRight:
                      isAI ? const Radius.circular(14) : Radius.zero,
                ),
              ),
              child: MyText.bodySmall(
                text,
                color: textColor,
                height: 1.4,
              ),
            ),
          ),
          if (!isAI) ...[
            MySpacing.width(8),
            const Icon(LucideIcons.user, color: Colors.black54, size: 18),
          ],
        ],
      ),
    );
  }

  // Prompt submit
  Future<void> _handlePromptSubmission() async {
    final promptText = _promptController.text.trim();
    if (promptText.isEmpty || _isLoading.value || _isAnalyzingData.value) {
      return;
    }

    _chatHistory.add({'sender': 'user', 'message': promptText});
    _promptController.clear();
    _scrollToBottom();

    _isLoading.value = true;
    _error.value = '';

    // Placeholder
    _chatHistory.add({'sender': 'ai', 'message': 'Thinking...'});
    _scrollToBottom();
    final placeholderIndex = _chatHistory.length - 1;

    try {
      final result = await GeminiService.generateText(promptText);
      if (placeholderIndex >= 0 &&
          _chatHistory.length > placeholderIndex) {
        _chatHistory[placeholderIndex] = {
          'sender': 'ai',
          'message': result,
        };
      }
      _scrollToBottom();
    } catch (e, stack) {
      // ignore: avoid_print
      print("Gemini Error: $e\n$stack");
      _error.value =
          "An error occurred. Failed to get response: ${e.toString().split(':').first}";
      if (placeholderIndex >= 0 &&
          _chatHistory.length > placeholderIndex) {
        _chatHistory.removeAt(placeholderIndex);
      }
    } finally {
      _isLoading.value = false;
    }
  }

  // Expense analysis
  Future<void> _handleDataAnalysis() async {
    if (_isLoading.value || _isAnalyzingData.value) return;

    _isAnalyzingData.value = true;
    _error.value = '';

    const String analysisPrompt = 'Analyze my monthly expense overview.';
    _chatHistory.add({'sender': 'user', 'message': analysisPrompt});
    _chatHistory
        .add({'sender': 'ai', 'message': 'Analyzing monthly expenses...'});
    _scrollToBottom();
    final placeholderIndex = _chatHistory.length - 1;

    try {
      await widget.dashboardController.fetchMonthlyExpenses();
      final rawDataList = widget.dashboardController.monthlyExpenseList;

      if (rawDataList.isEmpty) {
        _error.value = "No monthly expense data found for analysis.";
        _chatHistory.removeAt(placeholderIndex);
        return;
      }

      final rawDataJson =
          jsonEncode(rawDataList.map((e) => e.toJson()).toList());

      final prompt =
          "Analyze the following monthly expense data and provide a concise "
          "summary, key trends (like increasing/decreasing expenses), and "
          "highlight the highest expense months. The data is a list of "
          "monthly expense summaries over time in JSON format:\n\n$rawDataJson";

      final result = await GeminiService.generateText(prompt);

      if (placeholderIndex >= 0 &&
          _chatHistory.length > placeholderIndex) {
        _chatHistory[placeholderIndex] = {
          'sender': 'ai',
          'message': result,
        };
      }
      _scrollToBottom();
    } catch (e, stack) {
      // ignore: avoid_print
      print("Gemini Data Analysis Error: $e\n$stack");
      _error.value =
          "Failed to analyze data. An error occurred: ${e.toString().split(':').first}";
      if (placeholderIndex >= 0 &&
          _chatHistory.length > placeholderIndex) {
        _chatHistory.removeAt(placeholderIndex);
      }
    } finally {
      _isAnalyzingData.value = false;
    }
  }

  // Small floating chat panel (mobile-friendly)
  Widget _buildFloatingPanel(BuildContext context) {
    final media = MediaQuery.of(context).size;
    final double panelWidth = media.width * 0.9;
    final double panelHeight = media.height * 0.45;

    return FadeTransition(
      opacity: _opacityAnimation,
      child: ScaleTransition(
        scale: _scaleAnimation,
        alignment: Alignment.bottomRight,
        child: Align(
          alignment: Alignment.bottomRight,
          child: Container(
            width: panelWidth,
            height: panelHeight,
            margin: const EdgeInsets.only(right: 16, bottom: 80),
            padding: const EdgeInsets.all(12),
            decoration: BoxDecoration(
              color: Colors.white,
              borderRadius: BorderRadius.circular(18),
              boxShadow: [
                BoxShadow(
                  color: Colors.black.withOpacity(0.18),
                  blurRadius: 18,
                  offset: const Offset(0, 8),
                ),
              ],
            ),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                // Header
                Row(
                  children: [
                    Container(
                      padding: const EdgeInsets.all(6),
                      decoration: BoxDecoration(
                        color: contentTheme.primary.withOpacity(0.1),
                        shape: BoxShape.circle,
                      ),
                      child: const Icon(
                        LucideIcons.bot,
                        size: 18,
                        color: Colors.blue,
                      ),
                    ),
                    MySpacing.width(8),
                    Expanded(
                      child: MyText.titleSmall(
                        "Gemini AI Assistant",
                        fontWeight: 700,
                        overflow: TextOverflow.ellipsis,
                      ),
                    ),
                    IconButton(
                      splashRadius: 18,
                      iconSize: 18,
                      onPressed: _toggleOpen,
                      icon: const Icon(Icons.close, color: Colors.black54),
                    ),
                  ],
                ),
                MySpacing.height(4),
                MyText.labelSmall(
                  "Ask questions or analyze expenses.",
                  color: Colors.grey.shade600,
                ),
                MySpacing.height(8),

                // Error
                Obx(
                  () => _error.value.isNotEmpty
                      ? Container(
                          padding: const EdgeInsets.all(8),
                          margin: const EdgeInsets.only(bottom: 8),
                          decoration: BoxDecoration(
                            color: Colors.red.shade50,
                            borderRadius: BorderRadius.circular(8),
                            border:
                                Border.all(color: Colors.red.shade200),
                          ),
                          child: Row(
                            crossAxisAlignment: CrossAxisAlignment.start,
                            children: [
                              const Icon(
                                LucideIcons.badge_alert,
                                color: Colors.red,
                                size: 16,
                              ),
                              MySpacing.width(6),
                              Expanded(
                                child: MyText.bodySmall(
                                  _error.value,
                                  color: Colors.red.shade800,
                                ),
                              ),
                            ],
                          ),
                        )
                      : const SizedBox.shrink(),
                ),

                // Chat list
                Expanded(
                  child: Obx(
                    () {
                      if (_chatHistory.isEmpty) {
                        return Center(
                          child: Column(
                            mainAxisSize: MainAxisSize.min,
                            children: [
                              Icon(
                                LucideIcons.bot,
                                size: 40,
                                color: Colors.blue.shade300,
                              ),
                              MySpacing.height(6),
                              Text(
                                "Ask me about your data!",
                                style: TextStyle(
                                  color: Colors.grey.shade500,
                                ),
                              ),
                            ],
                          ),
                        );
                      }
                      return ListView.builder(
                        controller: _scrollController,
                        itemCount: _chatHistory.length,
                        padding:
                            const EdgeInsets.symmetric(vertical: 4),
                        itemBuilder: (context, index) {
                          final message = _chatHistory[index];
                          return _buildResponseBubble(
                            message['message'] ?? '',
                            message['sender'] == 'ai',
                          );
                        },
                      );
                    },
                  ),
                ),
                MySpacing.height(6),

                // Bottom row: Analyze + input
                Row(
                  children: [
                    Obx(
                      () => IconButton(
                        splashRadius: 18,
                        onPressed: (_isAnalyzingData.value ||
                                _isLoading.value)
                            ? null
                            : _handleDataAnalysis,
                        iconSize: 22,
                        icon: _isAnalyzingData.value
                            ? SizedBox(
                                width: 18,
                                height: 18,
                                child: CircularProgressIndicator(
                                  strokeWidth: 2,
                                  color: contentTheme.primary,
                                ),
                              )
                            : const Icon(
                                LucideIcons.chart_line,
                                color: Colors.blue,
                              ),
                        tooltip: 'Analyze expenses',
                      ),
                    ),
                    Expanded(
                      child: Container(
                        padding: const EdgeInsets.symmetric(
                            horizontal: 10, vertical: 4),
                        decoration: BoxDecoration(
                          color: Colors.grey.shade100,
                          borderRadius: BorderRadius.circular(999),
                          border: Border.all(
                            color: Colors.grey.shade300,
                          ),
                        ),
                        child: Row(
                          children: [
                            Expanded(
                              child: TextField(
                                controller: _promptController,
                                minLines: 1,
                                maxLines: 3,
                                keyboardType: TextInputType.multiline,
                                decoration: InputDecoration(
                                  hintText: "Ask Gemini…",
                                  border: InputBorder.none,
                                  isDense: true,
                                  hintStyle: TextStyle(
                                    color: Colors.grey.shade500,
                                    fontSize: 13,
                                  ),
                                ),
                                onSubmitted: (_) =>
                                    _handlePromptSubmission(),
                                enabled: !_isAnalyzingData.value,
                              ),
                            ),
                            Obx(
                              () => IconButton(
                                splashRadius: 18,
                                iconSize: 18,
                                onPressed: (_isLoading.value ||
                                        _isAnalyzingData.value ||
                                        _promptController.text
                                            .trim()
                                            .isEmpty)
                                    ? null
                                    : _handlePromptSubmission,
                                icon: _isLoading.value
                                    ? SizedBox(
                                        width: 18,
                                        height: 18,
                                        child: CircularProgressIndicator(
                                          strokeWidth: 2,
                                          color: contentTheme.primary,
                                        ),
                                      )
                                    : Icon(
                                        LucideIcons.send,
                                        color: _promptController.text
                                                .trim()
                                                .isEmpty
                                            ? Colors.grey.shade400
                                            : contentTheme.primary,
                                      ),
                              ),
                            ),
                          ],
                        ),
                      ),
                    ),
                  ],
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }

  // FAB
  Widget _buildFab() {
    return Obx(
      () => AnimatedScale(
        scale: _isOpen.value ? 0.0 : 1.0,
        duration: const Duration(milliseconds: 200),
        curve: Curves.easeOut,
        child: FloatingActionButton.extended(
          onPressed: _toggleOpen,
          heroTag: 'gemini_fab',
          backgroundColor: contentTheme.primary,
          icon: const Icon(LucideIcons.bot),
          label: const Text(
            'Ask Me Anything',
            style: TextStyle(fontSize: 14, fontWeight: FontWeight.w600),
          ),
        ),
      ),
    );
  }

  // Dim background when open
  Widget _buildScrim() {
    return Obx(
      () => _isOpen.value
          ? FadeTransition(
              opacity: _opacityAnimation,
              child: GestureDetector(
                onTap: _toggleOpen,
                child: Container(
                  color: Colors.black.withOpacity(0.25),
                ),
              ),
            )
          : const SizedBox.shrink(),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Stack(
      children: [
        // Scrim behind panel
        _buildScrim(),
        // Panel
        _buildFloatingPanel(context),
        // FAB
        Positioned(
          bottom: 16,
          right: 16,
          child: _buildFab(),
        ),
      ],
    );
  }

  @override
  void dispose() {
    _promptController.dispose();
    _scrollController.dispose();
    _animController.dispose();
    super.dispose();
  }
}