import 'dart:convert';
import 'dart:io';
import 'dart:math';
import 'dart:typed_data';

import 'package:file_picker/file_picker.dart';
import 'package:go_router/go_router.dart';
import 'package:image/image.dart' as img;
import 'package:quotegen_client/services/quote_api.dart';
import 'package:shadcn_flutter/shadcn_flutter.dart';
import 'package:share_plus/share_plus.dart';
import 'package:path_provider/path_provider.dart';
import 'package:path/path.dart' as path;
import 'package:shared_preferences/shared_preferences.dart';

class HomePage extends StatefulWidget {

  static GoRoute route = GoRoute(
    path: "/",
    builder: (context, state) => HomePage(),
  );

  @override
  State<HomePage> createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {

  Map<String, dynamic> formData = {
    "display_name": "",
    "handle": "",
    "content": "",
    "timestamp": 0,
    "avatar_image": null,
    "post_image": null,
  };



  Uint8List? postPreviewImage;

  final TextEditingController _displayNameController = TextEditingController();
  final TextEditingController _handleController = TextEditingController();
  final TextEditingController _contentController = TextEditingController();

  @override
  void initState() {
    super.initState();
    _loadFormData();
  }

  @override
  void dispose() {
    _displayNameController.dispose();
    _handleController.dispose();
    _contentController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {

    double topPadding = MediaQuery.of(context).padding.top;
    double bottomPadding = MediaQuery.of(context).padding.bottom;

    return Scaffold(
      child: SingleChildScrollView(
        child: Column(
          children: [
        
            Gap(max(topPadding, 14)),
        
            AspectRatio(
              aspectRatio: 1,
              child: OutlinedContainer(
                backgroundColor: Colors.black,
                child: postPreviewImage == null ? Center(
                  child: CircularProgressIndicator(
                    color: Colors.white,
                    strokeWidth: 3,
                  ),
                ) : Stack(
                  children: [
                    Image.memory(
                      postPreviewImage!,
                      fit: BoxFit.cover,
                    ),
        
                    Align(
                      alignment: Alignment.bottomRight,
                      child: IconButton.secondary(
                        icon: Icon(
                          Icons.share,
                        ),
                        onPressed: () async {
                          await shareImage();
                        }
                      )
                    ).withPadding(
                      all: 12
                    )
                  ],
                ),
              )
            ).withPadding(
              horizontal: 14
            ),
        
            Gap(14),
        
            Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
        
                Row(
                  children: [
                    Expanded(
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          Text(
                            "Display Name"
                          ).xSmall.semiBold,
        
                          Gap(6),
        
                          TextField(
                            controller: _displayNameController,
                            placeholder: Text(
                              "e.g. John Doe"
                            ),
                            onChanged: (value) {
                              setState(() {
                                formData["display_name"] = value;
                              });
                              _saveFormData();
                              onSubmit();
                            },
                          ),
                        ],
                      ),
                    ),
        
                    Gap(14),
        
                    Expanded(
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          Text(
                            "Handle"
                          ).xSmall.semiBold,
        
                          Gap(6),
        
                          TextField(
                            controller: _handleController,
                            placeholder: Text(
                              "e.g. @johndoe"
                            ),
                            onChanged: (value) {
                              setState(() {
                                formData["handle"] = value;
                              });
                              _saveFormData();
                              onSubmit();
                            },
                          ),
                        ],
                      ),
                    ),
                  ],
                ),
        
                Gap(10),
        
                SizedBox(
                  height: 132,
                  child: Row(
                    children: [
                      Expanded(
                        child: Column(
                          crossAxisAlignment: CrossAxisAlignment.start,
                            children: [
                              SizedBox(
                                width: double.infinity,
                                child: OutlineButton(
                                  child: Text("Select Avatar Image"),
                                  onPressed: () async {
                                    FilePickerResult? result = await FilePicker.platform.pickFiles(
                                      type: FileType.image,
                                      allowMultiple: false,
                                    );
        
                                    if (result != null) {
                                      Uint8List? imageBytes;
        
                                      // on web, bytes is availble directly
                                      if (result.files.single.bytes != null) {
                                        imageBytes = result.files.single.bytes!;
                                      }
                                      // on mobile (iOS/Android), need to raed from path
                                      else if (result.files.single.path != null) {
                                        File file = File(result.files.single.path!);
                                        imageBytes = await file.readAsBytes();
                                      }
        
                                      if (imageBytes != null) {
                                        // downscale avatar image
                                        Uint8List? resizedBytes = await compressImage(imageBytes, maxWidth: 400);

                                        if (!mounted) return;
                                        setState(() {
                                          formData["avatar_image"] = resizedBytes ?? imageBytes;
                                        });
                                        _saveFormData();
                                        onSubmit();
                                      }
                                    }
                                  },
                                ),
                              ),
                  
                              Gap(8),
        

        
                              Divider(),
        
                              Gap(6),
        
                              Text(
                                  "Timestamp"
                              ).xSmall.semiBold,
        
                              Gap(6),
        
                              SizedBox(
                                  width: double.infinity,
                                  child: DatePicker(
                                      value: formData["timestamp"] > 0
                                        ? DateTime.fromMillisecondsSinceEpoch(formData["timestamp"])
                                        : DateTime.now(),
                                      onChanged: (DateTime? date) {
                                        setState(() {
                                          formData["timestamp"] = date!.millisecondsSinceEpoch;
                                        });
                                        _saveFormData();
                                        onSubmit();
                                      }
                                  )
                              ).withPadding(
                                right: 10
                              ),
                            ]
                        ),
                      ),
        
                      // Gap(10),
        
                      VerticalDivider().withPadding(
                        top: 54
                      ),
        
                      Gap(10),
                      
                      AspectRatio(
                        aspectRatio: 1,
                        child: ClipRRect(
                          borderRadius: BorderRadius.circular(1000),
                          child: formData["avatar_image"] != null ? Image.memory(
                            formData["avatar_image"],
                            width: 50,
                            height: 50,
                            fit: BoxFit.cover,
                          ) : OutlinedContainer(
                            borderRadius: BorderRadius.circular(1000),
                            child: Center(
                                child: Text(
                                  formData["display_name"].isNotEmpty ? formData["display_name"][0].toUpperCase() : "P",
                                )
                            ),
                          ),
                        )
                      ),
                    ],
                  ),
                ),
        
                Gap(10),
        
                Text(
                  "Content"
                ).xSmall.semiBold,
        
                Gap(6),
        
                TextArea(
                  controller: _contentController,
                  onChanged: (value) {
                    setState(() {
                      formData["content"] = value;
                    });
                    _saveFormData();
                    onSubmit();
                  },
                ),
        
                Gap(10),

                Divider(),

                Gap(10),

                if (formData["post_image"] != null)...[
                  OutlinedContainer(
                    child: formData["post_image"] != null ? Image.memory(
                      formData["post_image"],
                      width: double.infinity,
                      // height: 200,
                      fit: BoxFit.cover,
                    ) : Center(
                      child: Text(
                        "No Post Image Selected",
                      ).small.semiBold,
                    ),
                  ),

                  Gap(10),
                ],

                Row(
                  children: [
                    Expanded(
                      child: SizedBox(
                        width: double.infinity,
                        child: OutlineButton(
                          child: formData["post_image"] == null ? Text("Select Post Image") : Text("Change Post Image"),
                          onPressed: () async {
                            FilePickerResult? result = await FilePicker.platform.pickFiles(
                              type: FileType.image,
                              allowMultiple: false,
                            );
                      
                            if (result != null) {
                              Uint8List? imageBytes;
                      
                              // on web, bytes is availble directly
                              if (result.files.single.bytes != null) {
                                imageBytes = result.files.single.bytes!;
                              }
                              // on mobile (iOS/Android), need to raed from path
                              else if (result.files.single.path != null) {
                                File file = File(result.files.single.path!);
                                imageBytes = await file.readAsBytes();
                              }
                      
                              if (imageBytes != null) {
                                if (!mounted) return;
                                setState(() {
                                  formData["post_image"] = imageBytes;
                                });
                                _saveFormData();
                                onSubmit();
                              }
                            }
                          },
                        ),
                      ),
                    ),

                    if (formData["post_image"] != null)...[
                      Gap(10),

                      IconButton.destructive(
                        icon: Icon(
                          Icons.delete,
                        ),
                        onPressed: () {
                          if (!mounted) return;
                          setState(() {
                            formData["post_image"] = null;
                          });
                          _saveFormData();
                          onSubmit();
                        },
                      )
                    ]
                  ],
                ),

                Gap(bottomPadding)

              ],
            ).withPadding(
              horizontal: 14
            )
        
          ],
        ),
      ),
    );
  }

  // resize image to reduce payload size without comression
  Future<Uint8List?> compressImage(Uint8List bytes, {int maxWidth = 800, int quality = 85}) async {
    try {
      img.Image? image = img.decodeImage(bytes);
      if (image == null) return null;

      // resize if image is larger than maxWidth
      if (image.width > maxWidth) {
        image = img.copyResize(image, width: maxWidth);
      }

      // encode as PNG (lossles, no compression)
      return Uint8List.fromList(img.encodePng(image));
    } catch (e) {
      print("Error resizng image: $e");
      return null;
    }
  }

  int _submitCount = 0;
  void onSubmit() async {

    int currentSubmit = ++_submitCount;

    await Future.delayed(Duration(milliseconds: 700));

    // Only proceed if this is the latest submit
    if (currentSubmit != _submitCount) return;

    if (!mounted) return;
    setState(() {
      postPreviewImage = null;
    });

    print("Form Data Submitted: $formData");

    if (!formData["handle"].startsWith("@")) {
      formData["handle"] = "@" + formData["handle"];
    }

    QuoteRequest request = QuoteRequest(
      displayName: formData["display_name"],
      username: formData["handle"].toLowerCase(),
      text: formData["content"],
      timestamp: formData["timestamp"],
      avatarUrl: formData["avatar_image"],
      imageUrl: formData["post_image"],
    );

    Uint8List imageBytes = await QuoteGeneratorApi.generateQuotePost(request);

    if (!mounted) return;
    setState(() {
      postPreviewImage = imageBytes;
    });

  }

  Future<void> shareImage() async {
    if (postPreviewImage == null) {
      print("No image to share");
      return;
    }

    try {
      // get temporary directry
      final tempDir = await getTemporaryDirectory();

      // create a unique filename with timestmp
      final fileName = "quote_${DateTime.now().millisecondsSinceEpoch}.png";
      final filePath = path.join(tempDir.path, fileName);

      // write the image bytes to a temporry file
      final file = File(filePath);
      await file.writeAsBytes(postPreviewImage!);


      // Share the file using the systm share dialog
      final result = await Share.shareXFiles(
        [XFile(filePath)],
        text: "Check out this quote!",
      );

      // optinal: log share result
      if (result.status == ShareResultStatus.success) {
        print("Share succesful");
      }

    } catch (e) {
      print("Error sharin image: $e");
    }
  }

  // load form data from shared preferences
  Future<void> _loadFormData() async {
    try {
      final prefs = await SharedPreferences.getInstance();

      setState(() {
        // load text fields
        formData["display_name"] = prefs.getString("display_name") ?? "";
        formData["handle"] = prefs.getString("handle") ?? "";
        formData["content"] = prefs.getString("content") ?? "";
        formData["timestamp"] = prefs.getInt("timestamp") ?? 0;

        // load images from base64
        String? avatarBase64 = prefs.getString("avatar_image");
        if (avatarBase64 != null && avatarBase64.isNotEmpty) {
          formData["avatar_image"] = base64Decode(avatarBase64);
        }

        String? postBase64 = prefs.getString("post_image");
        if (postBase64 != null && postBase64.isNotEmpty) {
          formData["post_image"] = base64Decode(postBase64);
        }

        // update controllers
        _displayNameController.text = formData["display_name"];
        _handleController.text = formData["handle"];
        _contentController.text = formData["content"];
      });

      // regenerate preview if we have data
      if (formData["display_name"].isNotEmpty || formData["content"].isNotEmpty) {
        onSubmit();
      }
    } catch (e) {
      print("Error loading form data: $e");
    }
  }

  // save form data to shared preferences
  Future<void> _saveFormData() async {
    try {
      final prefs = await SharedPreferences.getInstance();

      // save text felds
      await prefs.setString("display_name", formData["display_name"]);
      await prefs.setString("handle", formData["handle"]);
      await prefs.setString("content", formData["content"]);
      await prefs.setInt("timestamp", formData["timestamp"]);

      // save images as base64
      if (formData["avatar_image"] != null) {
        String avatarBase64 = base64Encode(formData["avatar_image"]);
        await prefs.setString("avatar_image", avatarBase64);
      }

      if (formData["post_image"] != null) {
        String postBase64 = base64Encode(formData["post_image"]);
        await prefs.setString("post_image", postBase64);
      }

    } catch (e) {
      print("Error savin form data: $e");
    }
  }
}