import 'package:flutter/material.dart';
import 'package:intl/intl.dart';
import 'package:url_launcher/url_launcher.dart';
import 'package:provider/provider.dart';
import 'package:file_picker/file_picker.dart';
import 'package:open_filex/open_filex.dart';
import 'dart:io';
import '../models/project_model.dart';
import '../models/branch_model.dart';
import '../models/project_doc_model.dart';
import '../models/task_log_model.dart';
import '../services/project_service.dart';
import '../services/task_log_service.dart';
import 'project_form_screen.dart';

class ProjectDetailScreen extends StatefulWidget {
  final ProjectModel project;
  const ProjectDetailScreen({super.key, required this.project});

  @override
  State<ProjectDetailScreen> createState() => _ProjectDetailScreenState();
}

class _ProjectDetailScreenState extends State<ProjectDetailScreen> {
  bool _isUploading = false;
  bool _isEditMode = false;
  late List<String> _currentFlavors;

  @override
  void initState() {
    super.initState();
    _currentFlavors = List.from(widget.project.flavors);
  }

  void _launchURL(String? url) async {
    if (url == null || url.isEmpty) return;
    final uri = Uri.parse(url);
    try {
      if (!await launchUrl(uri, mode: LaunchMode.externalApplication)) {
         throw 'Could not launch $url';
      }
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text(e.toString())));
      }
    }
  }

  void _addBranch() {
    final controller = TextEditingController();
    showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text("New Branch"),
        content: TextField(
          controller: controller, 
          decoration: const InputDecoration(hintText: "e.g. main, develop, feature/auth"),
          autofocus: true,
        ),
        actions: [
          TextButton(onPressed: () => Navigator.pop(ctx), child: const Text("CANCEL")),
          TextButton(
            onPressed: () {
              if (controller.text.isNotEmpty) {
                context.read<ProjectService>().addBranch(widget.project.id, controller.text.trim());
              }
              Navigator.pop(ctx);
            }, 
            child: const Text("ADD"),
          ),
        ],
      ),
    );
  }

  void _addFlavor() {
    final controller = TextEditingController();
    showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text("Add Project Flavor"),
        content: TextField(
          controller: controller, 
          decoration: const InputDecoration(hintText: "e.g. dev, prod, staging"),
          autofocus: true,
        ),
        actions: [
          TextButton(onPressed: () => Navigator.pop(ctx), child: const Text("CANCEL")),
          TextButton(
            onPressed: () async {
              String f = controller.text.trim();
              if (f.isNotEmpty && !_currentFlavors.contains(f)) {
                setState(() => _currentFlavors.add(f));
                final updatedProject = ProjectModel(
                  id: widget.project.id,
                  name: widget.project.name,
                  gitUrl: widget.project.gitUrl,
                  apiDocUrl: widget.project.apiDocUrl,
                  description: widget.project.description,
                  flavors: _currentFlavors,
                  createdAt: widget.project.createdAt,
                );
                await context.read<ProjectService>().updateProject(updatedProject);
              }
              if (mounted) Navigator.pop(ctx);
            }, 
            child: const Text("ADD"),
          ),
        ],
      ),
    );
  }

  void _deleteFlavor(String flavor) async {
    setState(() => _currentFlavors.remove(flavor));
    final updatedProject = ProjectModel(
      id: widget.project.id,
      name: widget.project.name,
      gitUrl: widget.project.gitUrl,
      apiDocUrl: widget.project.apiDocUrl,
      description: widget.project.description,
      flavors: _currentFlavors,
      createdAt: widget.project.createdAt,
    );
    await context.read<ProjectService>().updateProject(updatedProject);
  }

  void _addDocDialog() {
    showModalBottomSheet(
      context: context,
      builder: (ctx) => Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          ListTile(
            leading: const Icon(Icons.link, color: Colors.blue),
            title: const Text("Add Link"),
            onTap: () {
              Navigator.pop(ctx);
              _addLinkDoc();
            },
          ),
          ListTile(
            leading: const Icon(Icons.picture_as_pdf, color: Colors.red),
            title: const Text("Upload PDF"),
            onTap: () {
              Navigator.pop(ctx);
              _uploadPDFDoc();
            },
          ),
          const SizedBox(height: 20),
        ],
      ),
    );
  }

  void _addLinkDoc() {
    final titleCtrl = TextEditingController();
    final urlCtrl = TextEditingController();
    showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text("Add Link Document"),
        content: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            TextField(controller: titleCtrl, decoration: const InputDecoration(labelText: "Label")),
            TextField(controller: urlCtrl, decoration: const InputDecoration(labelText: "URL")),
          ],
        ),
        actions: [
          TextButton(onPressed: () => Navigator.pop(ctx), child: const Text("CANCEL")),
          TextButton(
            onPressed: () {
              if (titleCtrl.text.isNotEmpty && urlCtrl.text.isNotEmpty) {
                context.read<ProjectService>().addDoc(
                  widget.project.id, titleCtrl.text.trim(), urlCtrl.text.trim(), 'link'
                );
              }
              Navigator.pop(ctx);
            }, 
            child: const Text("SAVE"),
          ),
        ],
      ),
    );
  }

  void _uploadPDFDoc() async {
    FilePickerResult? result = await FilePicker.platform.pickFiles(
      type: FileType.custom,
      allowedExtensions: ['pdf'],
    );

    if (result != null) {
      setState(() => _isUploading = true);
      try {
        File file = File(result.files.single.path!);
        String label = result.files.single.name;
        String url = await context.read<ProjectService>().uploadDoc(widget.project.id, file);
        await context.read<ProjectService>().addDoc(widget.project.id, label, url, 'pdf');
      } catch (e) {
        if (mounted) ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text("Upload failed: $e")));
      } finally {
        if (mounted) setState(() => _isUploading = false);
      }
    }
  }

  void _confirmDeleteProject() {
    showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text("Delete Project"),
        content: Text("Are you sure? All data related to '${widget.project.name}' will be lost."),
        actions: [
          TextButton(onPressed: () => Navigator.pop(ctx), child: const Text("CANCEL")),
          TextButton(
            onPressed: () async {
              await context.read<ProjectService>().deleteProject(widget.project.id);
              if (mounted) {
                Navigator.pop(ctx);
                Navigator.pop(context);
              }
            }, 
            child: const Text("DELETE PROJECT", style: TextStyle(color: Colors.red)),
          ),
        ],
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: const Color(0xFFF8FAFC),
      appBar: AppBar(
        title: Text(widget.project.name),
        actions: [
          if (_isEditMode) ...[
            IconButton(
              onPressed: () => Navigator.push(
                context, 
                MaterialPageRoute(builder: (_) => ProjectFormScreen(project: widget.project))
              ), 
              icon: const Icon(Icons.settings_outlined),
              tooltip: "Project Settings",
            ),
            IconButton(
              onPressed: _confirmDeleteProject, 
              icon: const Icon(Icons.delete_forever, color: Colors.red),
              tooltip: "Delete Project",
            ),
          ],
          IconButton(
            onPressed: () => setState(() => _isEditMode = !_isEditMode), 
            icon: Icon(_isEditMode ? Icons.check_circle_rounded : Icons.edit_rounded, color: _isEditMode ? Colors.green : null),
            tooltip: _isEditMode ? "Finish Editing" : "Edit Mode",
          ),
        ],
      ),
      body: SingleChildScrollView(
        padding: const EdgeInsets.all(20),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            _buildLatestActivity(),
            const SizedBox(height: 32),
            _buildSectionHeader("Quick Links"),
            Row(
              children: [
                _linkTile("GIT REPO", Icons.code_rounded, widget.project.gitUrl),
                if (widget.project.apiDocUrl != null) ...[
                  const SizedBox(width: 12),
                  _linkTile("API DOCS", Icons.api_rounded, widget.project.apiDocUrl!),
                ],
              ],
            ),
            const SizedBox(height: 32),
            _buildSectionHeader("Description"),
            Text(
              widget.project.description, 
              style: const TextStyle(height: 1.6, color: Color(0xFF475569)),
            ),
            const SizedBox(height: 32),
            _isEditMode 
              ? _buildSectionHeaderWithAction("Branches", Icons.add_rounded, _addBranch)
              : _buildSectionHeader("Branches"),
            _buildBranchList(),
            const SizedBox(height: 32),
            _isEditMode 
              ? _buildSectionHeaderWithAction("Project Flavors", Icons.add_rounded, _addFlavor)
              : _buildSectionHeader("Project Flavors"),
            _buildFlavorList(),
            const SizedBox(height: 32),
            _isEditMode 
              ? _buildSectionHeaderWithAction("Documents", Icons.add_rounded, _addDocDialog)
              : _buildSectionHeader("Documents"),
            if (_isUploading) const Padding(
              padding: EdgeInsets.only(bottom: 12),
              child: LinearProgressIndicator(),
            ),
            _buildDocList(),
          ],
        ),
      ),
    );
  }

  Widget _buildLatestActivity() {
    return FutureBuilder<TaskLogModel?>(
      future: context.read<TaskLogService>().getLatestLogForProject(widget.project.id),
      builder: (context, snapshot) {
        if (snapshot.connectionState == ConnectionState.waiting) {
          return Container(
            height: 80,
            alignment: Alignment.center,
            decoration: BoxDecoration(color: Colors.grey.shade100, borderRadius: BorderRadius.circular(24)),
            child: const CircularProgressIndicator(strokeWidth: 2),
          );
        }
        
        if (snapshot.hasError) {
          return Container(
            padding: const EdgeInsets.all(16),
            decoration: BoxDecoration(color: Colors.red.shade50, borderRadius: BorderRadius.circular(16)),
            child: Column(
              children: [
                const Icon(Icons.error_outline, color: Colors.red),
                const SizedBox(height: 8),
                Text(
                  "Query Error: ${snapshot.error}. Check if a Firestore Index is needed.",
                  style: const TextStyle(color: Colors.red, fontSize: 11, fontWeight: FontWeight.bold),
                  textAlign: TextAlign.center,
                ),
              ],
            ),
          );
        }

        final log = snapshot.data;
        if (log == null) {
          return Container(
            padding: const EdgeInsets.all(24),
            decoration: BoxDecoration(
              color: Colors.white,
              borderRadius: BorderRadius.circular(24),
              border: Border.all(color: Colors.grey.shade100),
            ),
            child: const Row(
              children: [
                Icon(Icons.info_outline_rounded, color: Colors.indigo),
                SizedBox(width: 16),
                Text(
                  "No activity tracked for this project yet.",
                  style: TextStyle(color: Color(0xFF64748B), fontSize: 13, fontWeight: FontWeight.w500),
                ),
              ],
            ),
          );
        }

        return Container(
          padding: const EdgeInsets.all(24),
          decoration: BoxDecoration(
            gradient: const LinearGradient(
              colors: [Color(0xFF1E293B), Color(0xFF0F172A)],
              begin: Alignment.topLeft,
              end: Alignment.bottomRight,
            ),
            borderRadius: BorderRadius.circular(32),
            boxShadow: [
              BoxShadow(
                color: const Color(0xFF0F172A).withOpacity(0.1),
                blurRadius: 20,
                offset: const Offset(0, 10),
              ),
            ],
          ),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Row(
                mainAxisAlignment: MainAxisAlignment.spaceBetween,
                children: [
                  const Text(
                    "LATEST ACTIVITY", 
                    style: TextStyle(color: Colors.white54, fontSize: 10, fontWeight: FontWeight.bold, letterSpacing: 1.5),
                  ),
                  if (log.flavor != null)
                   Container(
                    padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 4),
                    decoration: BoxDecoration(
                      color: const Color(0xFF6366F1),
                      borderRadius: BorderRadius.circular(8),
                    ),
                    child: Text(
                      log.flavor!.toUpperCase(),
                      style: const TextStyle(color: Colors.white, fontSize: 9, fontWeight: FontWeight.bold),
                    ),
                  ),
                ],
              ),
              const SizedBox(height: 20),
              Row(
                children: [
                  CircleAvatar(
                    radius: 20,
                    backgroundColor: Colors.white.withOpacity(0.1),
                    child: const Icon(Icons.person_rounded, color: Colors.white70),
                  ),
                  const SizedBox(width: 16),
                  Expanded(
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                         Text(
                           log.userName, 
                           style: const TextStyle(color: Colors.white, fontWeight: FontWeight.bold, fontSize: 18),
                         ),
                         Text(
                           "Worked on ${log.moduleName}", 
                           style: const TextStyle(color: Colors.white60, fontSize: 12),
                         ),
                      ],
                    ),
                  ),
                  Column(
                    crossAxisAlignment: CrossAxisAlignment.end,
                    children: [
                       Text(
                         DateFormat('dd MMM').format(log.date), 
                         style: const TextStyle(color: Colors.white, fontWeight: FontWeight.bold, fontSize: 14),
                       ),
                       Text(
                         DateFormat('yyyy').format(log.date), 
                         style: const TextStyle(color: Colors.white38, fontSize: 10),
                       ),
                    ],
                  ),
                ],
              ),
            ],
          ),
        );
      },
    );
  }

  Widget _buildSectionHeader(String title) {
    return Padding(
      padding: const EdgeInsets.only(bottom: 16),
      child: Text(
        title.toUpperCase(), 
        style: const TextStyle(
          fontWeight: FontWeight.bold, 
          fontSize: 12, 
          color: Color(0xFF6366F1),
          letterSpacing: 1.2
        ),
      ),
    );
  }

  Widget _buildSectionHeaderWithAction(String title, IconData icon, VoidCallback onTap) {
    return Row(
      mainAxisAlignment: MainAxisAlignment.spaceBetween,
      children: [
        _buildSectionHeader(title),
        TextButton.icon(
          onPressed: onTap, 
          icon: Icon(icon, size: 16), 
          label: const Text("ADD", style: TextStyle(fontWeight: FontWeight.bold, fontSize: 11)),
          style: TextButton.styleFrom(foregroundColor: const Color(0xFF6366F1)),
        ),
      ],
    );
  }

  Widget _linkTile(String label, IconData icon, String url) {
    return Expanded(
      child: Material(
        color: Colors.white,
        borderRadius: BorderRadius.circular(20),
        child: InkWell(
          onTap: () => _launchURL(url),
           borderRadius: BorderRadius.circular(20),
          child: Container(
            padding: const EdgeInsets.symmetric(vertical: 20),
            decoration: BoxDecoration(
              border: Border.all(color: Colors.grey.shade100),
              borderRadius: BorderRadius.circular(20),
            ),
            child: Column(
              children: [
                Icon(icon, color: const Color(0xFF6366F1), size: 28),
                const SizedBox(height: 12),
                Text(
                  label, 
                  style: const TextStyle(fontWeight: FontWeight.bold, fontSize: 11, color: Color(0xFF1E293B), letterSpacing: 0.5),
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }

  Widget _buildBranchList() {
    return StreamBuilder<List<BranchModel>>(
      stream: context.read<ProjectService>().getBranches(widget.project.id),
      builder: (context, snapshot) {
        if (!snapshot.hasData) return const SizedBox();
        final branches = snapshot.data!;
        if (branches.isEmpty) return const Text("No active branches recorded.", style: TextStyle(color: Color(0xFF94A3B8), fontSize: 12, fontStyle: FontStyle.italic));
        
        return Wrap(
          spacing: 10,
          runSpacing: 10,
          children: branches.map((b) => Chip(
            label: Text(b.name, style: const TextStyle(fontSize: 12, fontWeight: FontWeight.w600)),
            backgroundColor: const Color(0xFFF1F5F9),
            side: BorderSide.none,
            shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
            onDeleted: _isEditMode ? () {
              context.read<ProjectService>().deleteBranch(widget.project.id, b.id);
            } : null,
            deleteIconColor: const Color(0xFFF43F5E),
            deleteIcon: const Icon(Icons.close_rounded, size: 14),
          )).toList(),
        );
      },
    );
  }

  Widget _buildFlavorList() {
     if (_currentFlavors.isEmpty) {
        return const Text("No flavors defined yet.", style: TextStyle(color: Color(0xFF94A3B8), fontSize: 12, fontStyle: FontStyle.italic));
     }
     return Wrap(
       spacing: 10,
       runSpacing: 10,
       children: _currentFlavors.map((flavor) => Chip(
         label: Text(flavor, style: const TextStyle(fontSize: 12, fontWeight: FontWeight.bold)),
         backgroundColor: const Color(0xFFEEF2FF),
         labelStyle: const TextStyle(color: Color(0xFF6366F1)),
         side: BorderSide.none,
         shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
         onDeleted: _isEditMode ? () => _deleteFlavor(flavor) : null,
         deleteIconColor: const Color(0xFFF43F5E),
         deleteIcon: const Icon(Icons.close_rounded, size: 14),
       )).toList(),
     );
  }

  Widget _buildDocList() {
    return StreamBuilder<List<ProjectDocModel>>(
      stream: context.read<ProjectService>().getDocs(widget.project.id),
      builder: (context, snapshot) {
        if (!snapshot.hasData) return const SizedBox();
        final docs = snapshot.data!;
        if (docs.isEmpty) return const Text("No documents or technical specs.", style: TextStyle(color: Color(0xFF94A3B8), fontSize: 12, fontStyle: FontStyle.italic));

        return ListView.builder(
          shrinkWrap: true,
          physics: const NeverScrollableScrollPhysics(),
          itemCount: docs.length,
          itemBuilder: (context, index) {
            final doc = docs[index];
            return Container(
              margin: const EdgeInsets.only(bottom: 8),
              decoration: BoxDecoration(
                color: Colors.white,
                borderRadius: BorderRadius.circular(16),
                border: Border.all(color: Colors.grey.shade100),
              ),
              child: ListTile(
                contentPadding: const EdgeInsets.symmetric(horizontal: 16, vertical: 4),
                leading: Container(
                  padding: const EdgeInsets.all(8),
                  decoration: BoxDecoration(
                    color: (doc.type == 'pdf' ? const Color(0xFFF43F5E) : Colors.blue).withOpacity(0.1),
                    borderRadius: BorderRadius.circular(10),
                  ),
                  child: Icon(
                    doc.type == 'pdf' ? Icons.picture_as_pdf_rounded : Icons.link_rounded, 
                    color: doc.type == 'pdf' ? const Color(0xFFF43F5E) : Colors.blue,
                    size: 20,
                  ),
                ),
                title: Text(doc.label, style: const TextStyle(fontSize: 13, fontWeight: FontWeight.bold, color: Color(0xFF1E293B))),
                trailing: _isEditMode 
                  ? IconButton(
                      onPressed: () => context.read<ProjectService>().deleteDoc(widget.project.id, doc.id),
                      icon: const Icon(Icons.delete_outline_rounded, size: 18, color: Color(0xFFF43F5E)),
                    )
                  : const Icon(Icons.arrow_forward_ios_rounded, size: 14, color: Color(0xFF94A3B8)),
                onTap: () {
                  if (!_isEditMode) {
                    if (doc.type == 'pdf') {
                      OpenFilex.open(doc.url);
                    } else {
                      _launchURL(doc.url);
                    }
                  }
                },
              ),
            );
          },
        );
      },
    );
  }
}