using Qrakhen.Qamp.Editor.Commands;
using Qrakhen.Qamp.Editor.Primitives;
using Qrakhen.Qamp.Memory;
using System.Collections.ObjectModel;
using System.Windows.Input;

namespace Qrakhen.Qamp.Editor.ViewModel;

public class EditorFrameViewModel : ObservableObject
{
    private CursorPosition _cursorPosition;
    public CursorPosition CursorPosition {
        get => _cursorPosition;
        set => SetProperty(ref _cursorPosition, value);
    }

    public int CursorLine {
        get => _cursorPosition.Line;
        set => SetProperty(ref _cursorPosition.Line, value);
    }

    public int CursorColumn {
        get => _cursorPosition.Column;
        set => SetProperty(ref _cursorPosition.Column, value);
    }

    public LineBuffer CurrentLineBuffer => Lines[CursorLine];

    public ICommand MoveCaretCommand { get; }

    public ObservableCollection<LineBuffer> Lines { get; private set; } = new() {
        new LineBuffer("test"),
        new LineBuffer("    is very good;"),
        new LineBuffer("    jaja();"),
        new LineBuffer("}")
    };

    public EditorFrameViewModel()
    {
        MoveCaretCommand = new RelayCommand(ExecuteMoveCaret, CanMoveCaret);
    }

    public void SetCursor(int line, int column)
    {
        line = line < 0 ? 0 : line >= Lines.Count ? Lines.Count - 1 : line;
        LineBuffer buffer = Lines[line];
        column = column < 0 ? 0 : column > buffer.Tail ? buffer.Tail : column;
        CursorPosition = new(line, column);
    }

    public void MoveCursor(int lines, int columns)
    {
        SetCursor(CursorLine + lines, CursorColumn + columns);
        OnPropertyChanged(nameof(CurrentLineBuffer));
    }

    public bool CanMoveCaret(object? relativeUpdate)
    {
        return true;
    }

    public void ExecuteMoveCaret(object? relativeUpdate)
    {
        if (relativeUpdate is CursorPosition pos)
            MoveCursor(pos.Line, pos.Column);
    }

    public void Delete(int count = 1, bool follow = true)
    {
        if (follow)
            MoveCursor(0, -count);
        CurrentLineBuffer.Delete(CursorColumn, count);
        OnPropertyChanged(nameof(Lines));
    }

    public void Insert(string data, bool follow = true)
    {
        CurrentLineBuffer.Insert(CursorColumn, data);
        if (follow)
            MoveCursor(0, data.Length);
        OnPropertyChanged(nameof(Lines));
    }
}