@page "/board"
@page "/projects/{ProjectId:long}/tasks"
@using Microsoft.AspNetCore.Authorization
@using TaskTrackingSystem.Shared.Models.Project
@rendermode @(new InteractiveServerRenderMode(prerender: false))
@attribute [Microsoft.AspNetCore.Authorization.Authorize]
@inject ApiClientService ApiClient
@inject NavigationManager Navigation
@inject IJSRuntime JS
@inject AuthenticationStateProvider AuthStateProvider
@inject MenuAuthorizationService MenuAuthorization

<PageTitle>Kanban Board</PageTitle>

<SuccessAlert Message="@successMessage" />

<div class="space-y-6">
    <!-- Page Header -->
    <div class="flex items-center justify-between">
        <div class="flex items-center space-x-4">
            @if (ProjectId > 0)
            {
                <button @onclick="GoBack" class="rounded-lg p-2 text-slate-400 hover:bg-slate-100 hover:text-slate-600 transition-all">
                    <i data-lucide="arrow-left" class="h-5 w-5"></i>
                </button>
            }
            <div>
                <h2 class="text-3xl font-bold tracking-tight text-slate-900">Kanban Board</h2>
                <p class="text-slate-500 mt-1 font-medium">@(project != null ? project.Name : (ProjectId > 0 ? $"Project #{ProjectId}" : "All Projects"))</p>
            </div>
        </div>
        <div class="flex flex-wrap items-center gap-3">
            <select value="@selectedProjectId" @onchange="OnProjectFilterChanged" class="rounded-lg border border-slate-200 bg-white px-3 py-2 text-sm text-slate-900 focus:outline-none focus:ring-2 focus:ring-slate-900 focus:border-transparent transition-all">
                <option value="0">All Projects</option>
                @foreach (var p in projects)
                {
                    <option value="@p.Id">@p.Name</option>
                }
            </select>
            <button @onclick="ToggleArchivedView" class="inline-flex items-center rounded-lg border border-slate-200 bg-white px-4 py-2.5 text-sm font-medium text-slate-700 hover:bg-slate-50 transition-colors shadow-sm">
                <i data-lucide="@(showArchivedTasks ? "layout-grid" : "archive")" class="h-4 w-4 mr-2 text-slate-500"></i>
                @(showArchivedTasks ? "Back to Board" : "Archived Tasks")
            </button>
            @if (canUpdateTask && !showArchivedTasks)
            {
                <button @onclick="RequestArchiveDoneConfirmation" class="inline-flex items-center rounded-lg border border-slate-200 bg-white px-4 py-2.5 text-sm font-medium text-slate-700 hover:bg-slate-50 transition-colors shadow-sm">
                    <i data-lucide="archive" class="h-4 w-4 mr-2 text-slate-500"></i>
                    Archive Done
                </button>
            }
            @if (canCreateTask && !showArchivedTasks)
            {
                <button @onclick="OpenCreateTaskModal" class="inline-flex items-center rounded-lg bg-violet-600 px-4 py-2.5 text-sm font-medium text-white hover:bg-violet-700 transition-colors shadow-sm">
                    <i data-lucide="plus" class="h-4 w-4 mr-2"></i>
                    New Task
                </button>
            }
        </div>
    </div>

    @if (!string.IsNullOrWhiteSpace(boardError))
    {
        <div class="rounded-xl border border-rose-200 bg-rose-50 px-4 py-3 text-sm font-medium text-rose-700">
            @boardError
        </div>
    }

    @if (isLoading)
    {
        <div class="flex items-center justify-center py-20">
            <div class="flex items-center space-x-3 text-slate-500">
                <svg class="animate-spin h-5 w-5" viewBox="0 0 24 24"><circle class="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" stroke-width="4" fill="none"></circle><path class="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4z"></path></svg>
                <span class="text-sm font-medium">Loading board...</span>
            </div>
        </div>
    }
    else
    {
        <!-- Kanban Columns -->
        <div class="mb-2 text-sm text-slate-500">
            @(showArchivedTasks ? "Viewing archived tasks." : "Drag tasks between columns to update their status.")
        </div>
        <div class="grid grid-cols-1 @(showArchivedTasks ? "md:grid-cols-1" : "md:grid-cols-3") gap-6">
            @foreach (var column in VisibleColumns)
            {
                var tasksInColumn = VisibleTasks.Where(t => t.StatusId == column.StatusId).ToList();
                <div @key="column.StatusId" class="flex flex-col rounded-xl border border-slate-200 bg-slate-50/50 overflow-hidden min-h-[400px]">
                    <!-- Column Header -->
                    <div class="flex items-center justify-between px-4 py-3 bg-white border-b border-slate-100">
                        <div class="flex items-center space-x-2">
                            <span class="h-2.5 w-2.5 rounded-full @column.DotColor"></span>
                            <h3 class="text-sm font-semibold text-slate-900">@column.Name</h3>
                        </div>
                        <span class="flex h-6 w-6 items-center justify-center rounded-full bg-slate-100 text-xs font-semibold text-slate-600">@tasksInColumn.Count</span>
                    </div>

                    <!-- Cards -->
                    <div class="flex-1 p-3 space-y-3 overflow-y-auto transition-colors @((!showArchivedTasks && dropTargetStatus == column.StatusId) ? "bg-slate-100" : "")"
                         @ondrop="() => HandleDrop(column.StatusId)"
                         @ondragenter="() => HandleDragEnter(column.StatusId)"
                         @ondragleave="HandleDragLeave"
                         @ondragover="HandleDragOver"
                         @ondragover:preventDefault="true">
                        @if (tasksInColumn.Any())
                        {
                            @foreach (var task in tasksInColumn)
                            {
                                <div @key="task.Id" class="select-none rounded-lg border border-slate-200 bg-white p-4 shadow-sm hover:shadow-md transition-shadow @((canUpdateTask && !showArchivedTasks) ? "cursor-grab active:cursor-grabbing" : "cursor-default")"
                                     data-task-id="@task.Id"
                                     draggable="@((canUpdateTask && !showArchivedTasks).ToString().ToLowerInvariant())"
                                     @ondragstart="() => HandleDragStart(task)"
                                     @ondragend="HandleDragEnd">
                                    <div class="flex items-start justify-between">
                                        <h4 class="text-sm font-semibold text-slate-900">@task.Title</h4>
                                        <span class="text-xs px-2 py-0.5 rounded-full font-medium @GetPriorityBadge(task.PriorityId)">@GetPriorityLabel(task.PriorityId)</span>
                                    </div>
                                    @if (!string.IsNullOrEmpty(task.Description))
                                    {
                                        <p class="text-xs text-slate-500 mt-1.5 line-clamp-2">@task.Description</p>
                                    }
                                    <div class="flex items-center justify-between mt-3 pt-3 border-t border-slate-50">
                                        <span class="text-xs text-slate-400">Due @DisplayFormats.Date(task.DueDate)</span>
                                        @if (showArchivedTasks)
                                        {
                                            <span class="rounded-full bg-slate-100 px-2 py-0.5 text-[10px] font-semibold uppercase tracking-wide text-slate-500">Archived</span>
                                        }
                                    </div>
                                </div>
                            }
                        }
                        else
                        {
                            <div class="flex items-center justify-center py-8 h-full">
                                <p class="text-xs text-slate-400">Drop tasks here</p>
                            </div>
                        }
                    </div>
                </div>
            }
        </div>
    }
</div>

@* ===== Create Task Modal ===== *@
@if (showTaskModal)
{
    <div class="fixed inset-0 z-50 flex items-center justify-center bg-black/40 backdrop-blur-sm">
        <div class="bg-white rounded-2xl shadow-lg w-full max-w-lg mx-4 overflow-hidden">
            <div class="flex items-center justify-between px-6 py-4 border-b border-slate-100">
                <h3 class="text-lg font-semibold text-slate-900">New Task</h3>
                <button @onclick="CloseTaskModal" class="rounded-lg p-1 text-slate-400 hover:bg-slate-100 hover:text-slate-600 transition-all">
                    <i data-lucide="x" class="h-5 w-5"></i>
                </button>
            </div>
            <div class="p-6 space-y-4">
                <div>
                    <label class="block text-sm font-medium text-slate-700 mb-1.5">Project</label>
                    <select @bind="taskProjectId" disabled="@(ProjectId > 0)" class="w-full rounded-lg border border-slate-200 px-3 py-2 text-sm text-slate-900 focus:outline-none focus:ring-2 focus:ring-slate-900 focus:border-transparent transition-all disabled:bg-slate-50 disabled:text-slate-500">
                        <option value="0">Select project...</option>
                        @foreach (var p in projects)
                        {
                            <option value="@p.Id">@p.Name</option>
                        }
                    </select>
                </div>
                <div>
                    <label class="block text-sm font-medium text-slate-700 mb-1.5">Title</label>
                    <input @bind="taskTitle" type="text" placeholder="Task title" class="w-full rounded-lg border border-slate-200 px-3 py-2 text-sm text-slate-900 placeholder:text-slate-400 focus:outline-none focus:ring-2 focus:ring-slate-900 focus:border-transparent transition-all" />
                </div>
                <div>
                    <label class="block text-sm font-medium text-slate-700 mb-1.5">Description</label>
                    <textarea @bind="taskDescription" rows="3" placeholder="Task description" class="w-full rounded-lg border border-slate-200 px-3 py-2 text-sm text-slate-900 placeholder:text-slate-400 focus:outline-none focus:ring-2 focus:ring-slate-900 focus:border-transparent transition-all"></textarea>
                </div>
                <div class="grid grid-cols-2 gap-4">
                    <div>
                        <label class="block text-sm font-medium text-slate-700 mb-1.5">Priority</label>
                        <select @bind="taskPriorityId" class="w-full rounded-lg border border-slate-200 px-3 py-2 text-sm text-slate-900 focus:outline-none focus:ring-2 focus:ring-slate-900 focus:border-transparent transition-all">
                            <option value="@TaskPriority.Low">Low</option>
                            <option value="@TaskPriority.Medium">Medium</option>
                            <option value="@TaskPriority.High">High</option>
                        </select>
                    </div>
                    <div>
                        <label class="block text-sm font-medium text-slate-700 mb-1.5">Due Date</label>
                        <input @bind="taskDueDate" type="date" class="w-full rounded-lg border border-slate-200 px-3 py-2 text-sm text-slate-900 focus:outline-none focus:ring-2 focus:ring-slate-900 focus:border-transparent transition-all" />
                    </div>
                </div>
                @if (!string.IsNullOrEmpty(taskError))
                {
                    <div class="p-3 rounded-lg bg-red-50 border border-red-100">
                        <p class="text-sm text-red-600">@taskError</p>
                    </div>
                }
            </div>
            <div class="flex items-center justify-end space-x-3 px-6 py-4 border-t border-slate-100 bg-slate-50/50">
                <button @onclick="CloseTaskModal" class="rounded-lg px-4 py-2 text-sm font-medium text-slate-600 hover:bg-slate-100 transition-colors">Cancel</button>
                <button @onclick="RequestCreateConfirmation" disabled="@isSaving" class="rounded-lg bg-violet-600 px-4 py-2 text-sm font-medium text-white hover:bg-violet-700 disabled:opacity-50 transition-colors">
                    @(isSaving ? "Creating..." : "Create Task")
                </button>
            </div>
        </div>
    </div>
}

@* ===== Confirm Dialog ===== *@
<ConfirmDialog IsVisible="showConfirmDialog"
               Title="@confirmTitle"
               Message="@confirmMessage"
               ConfirmText="@confirmButtonText"
               Icon="@confirmIcon"
               IconBgClass="@confirmIconBg"
               IconTextClass="@confirmIconText"
               ButtonClass="@confirmButtonClass"
               OnConfirm="HandleConfirmAction"
               OnCancel="CloseConfirmDialog" />

@code {
    [Parameter] public long ProjectId { get; set; }

    private bool isLoading = true;
    private bool isAdmin = false;
    private bool isManager = false;
    private bool canCreateTask = false;
    private bool canUpdateTask = false;
    private bool showArchivedTasks = false;
    private long currentUserId = 0;
    private ProjectDto? project;
    private bool showTaskModal = false;
    private bool isSaving = false;
    private string? taskError;
    private string? boardError;

    // Confirm dialog state
    private bool showConfirmDialog = false;
    private string? successMessage;
    private string confirmTitle = "";
    private string confirmMessage = "";
    private string confirmButtonText = "";
    private string confirmIcon = "";
    private string confirmIconBg = "";
    private string confirmIconText = "";
    private string confirmButtonClass = "";
    private Func<Task>? confirmAction;
    private List<TaskDto> tasks = new();
    private List<ProjectDto> projects = new();
    private long selectedProjectId = 0;

    // Task form
    private long taskProjectId;
    private string taskTitle = "";
    private string? taskDescription;
    private TaskPriority taskPriorityId = TaskPriority.Medium;
    private DateTime taskDueDate = DateTime.Today.AddDays(7);

    private List<KanbanColumn> columns = new()
    {
        new(AppTaskStatus.Todo, "To Do", "bg-slate-400"),
        new(AppTaskStatus.InProgress, "In Progress", "bg-blue-500"),
        new(AppTaskStatus.Done, "Done", "bg-emerald-500")
    };

    private TaskDto? draggedTask;
    private AppTaskStatus? dropTargetStatus;

    private IEnumerable<TaskDto> VisibleTasks =>
        selectedProjectId > 0
            ? tasks.Where(t => t.ProjectId == selectedProjectId)
            : tasks;

    private IEnumerable<KanbanColumn> VisibleColumns =>
        showArchivedTasks
            ? columns.Where(column => column.StatusId == AppTaskStatus.Done)
            : columns;

    private Task HandleDragStart(TaskDto task)
    {
        if (!canUpdateTask)
        {
            return Task.CompletedTask;
        }

        if (showArchivedTasks)
        {
            return Task.CompletedTask;
        }

        draggedTask = task;
        dropTargetStatus = null;
        return Task.CompletedTask;
    }

    private void HandleDragOver()
    {
        // Allow dropping
    }

    private void HandleDragEnter(AppTaskStatus statusId)
    {
        if (draggedTask != null)
        {
            dropTargetStatus = statusId;
        }
    }

    private void HandleDragLeave()
    {
        dropTargetStatus = null;
    }

    private async Task HandleDrop(AppTaskStatus newStatusId)
    {
        var taskToMove = draggedTask;

        if (taskToMove != null && taskToMove.StatusId != newStatusId)
        {
            await MoveTask(taskToMove.Id, newStatusId);
        }

        draggedTask = null;
        dropTargetStatus = null;
    }

    private Task HandleDragEnd()
    {
        draggedTask = null;
        dropTargetStatus = null;
        return Task.CompletedTask;
    }

    protected override async Task OnInitializedAsync()
    {
        var authState = await AuthStateProvider.GetAuthenticationStateAsync();
        var user = authState.User;
        isAdmin = user.IsInRole("Admin");
        isManager = user.IsInRole("Manager");
        canCreateTask = isAdmin || await MenuAuthorization.HasAccessCodeAsync(user, "Tasks_Create");
        canUpdateTask = isAdmin || await MenuAuthorization.HasAccessCodeAsync(user, "Tasks_Update");
        selectedProjectId = ProjectId > 0 ? ProjectId : 0;
        await LoadTasks();
    }

    protected override async Task OnAfterRenderAsync(bool firstRender)
    {
        await JS.InvokeVoidAsync("initIcons");
    }

    private async Task LoadTasks()
    {
        isLoading = true;
        var client = ApiClient.CreateClient();
        try
        {
            var authState = await AuthStateProvider.GetAuthenticationStateAsync();
            var user = authState.User;
            isAdmin = user.IsInRole("Admin");
            isManager = user.IsInRole("Manager");
            var idStr = user.FindFirst(System.Security.Claims.ClaimTypes.NameIdentifier)?.Value;
            if (idStr != null) long.TryParse(idStr, out currentUserId);

            var tasksTask = client.GetFromJsonAsync<List<TaskDto>>(showArchivedTasks ? "Task/archived" : "Task", Serialization.CaseInsensitive);
            var projectsTask = client.GetFromJsonAsync<List<ProjectDto>>("Project", Serialization.CaseInsensitive);
            await System.Threading.Tasks.Task.WhenAll(tasksTask, projectsTask);

            var allTasks = tasksTask.Result ?? new();
            projects = projectsTask.Result ?? new();
            project = selectedProjectId > 0 ? projects.FirstOrDefault(p => p.Id == selectedProjectId) : null;

            // Filter for non-admins and non-managers
            tasks = (!(isAdmin || isManager) && currentUserId > 0)
                ? allTasks.Where(t => t.AssignedTo == currentUserId).ToList()
                : allTasks;
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Load tasks error: {ex.Message}");
        }
        finally
        {
            isLoading = false;
        }
    }

    private async Task MoveTask(long taskId, AppTaskStatus newStatusId)
    {
        if (!canUpdateTask)
        {
            return;
        }

        var client = ApiClient.CreateClient();
        var task = tasks.FirstOrDefault(t => t.Id == taskId);
        var previousStatus = task?.StatusId;

        if (task != null)
        {
            task.StatusId = newStatusId;
            boardError = null;
            StateHasChanged();
        }

        try
        {
            var response = await client.PatchAsync($"Task/{taskId}/status?statusId={(long)newStatusId}", null);
            if (!response.IsSuccessStatusCode)
            {
                if (task != null && previousStatus.HasValue)
                {
                    task.StatusId = previousStatus.Value;
                }
                boardError = "Failed to move task. Please try again.";
            }
        }
        catch (Exception ex)
        {
            if (task != null && previousStatus.HasValue)
            {
                task.StatusId = previousStatus.Value;
            }
            await LoadTasks();
            Console.WriteLine($"Move task error: {ex.Message}");
            boardError = "Failed to move task. Please try again.";
        }
    }

    private void GoBack() => Navigation.NavigateTo("/projects/all");

    private async Task ToggleArchivedView()
    {
        showArchivedTasks = !showArchivedTasks;
        draggedTask = null;
        dropTargetStatus = null;
        boardError = null;
        await LoadTasks();
    }

    private void OnProjectFilterChanged(ChangeEventArgs e)
    {
        selectedProjectId = long.TryParse(e.Value?.ToString(), out var value) ? value : 0;
        project = selectedProjectId > 0 ? projects.FirstOrDefault(p => p.Id == selectedProjectId) : null;
        taskProjectId = selectedProjectId;
        boardError = null;
    }

    private void OpenCreateTaskModal()
    {
        taskProjectId = selectedProjectId > 0 ? selectedProjectId : projects.FirstOrDefault()?.Id ?? 0;
        taskTitle = "";
        taskDescription = null;
        taskPriorityId = TaskPriority.Medium;
        taskDueDate = DateTime.Today.AddDays(7);
        taskError = null;
        showTaskModal = true;
    }

    private void CloseTaskModal()
    {
        showTaskModal = false;
        taskError = null;
    }

    private void RequestCreateConfirmation()
    {
        if (string.IsNullOrWhiteSpace(taskTitle))
        {
            taskError = "Task title is required.";
            return;
        }
        if (taskProjectId == 0)
        {
            taskError = "Please select a project.";
            return;
        }

        confirmTitle = "Create Task?";
        confirmMessage = "Are you sure you want to create this task?";
        confirmButtonText = "Create";
        confirmIcon = "plus-circle";
        confirmIconBg = "bg-emerald-50";
        confirmIconText = "text-emerald-500";
        confirmButtonClass = "bg-violet-600 hover:bg-violet-700";
        confirmAction = CreateTask;
        showConfirmDialog = true;
    }

    private async Task HandleConfirmAction()
    {
        showConfirmDialog = false;
        if (confirmAction != null)
            await confirmAction();
    }

    private void CloseConfirmDialog()
    {
        showConfirmDialog = false;
    }

    private async Task CreateTask()
    {
        if (string.IsNullOrWhiteSpace(taskTitle))
        {
            taskError = "Task title is required.";
            return;
        }

        isSaving = true;
        taskError = null;
        var client = ApiClient.CreateClient();

        try
        {
            var dto = new CreateTaskDto
            {
                Title = taskTitle,
                Description = taskDescription,
                ProjectId = taskProjectId,
                StatusId = AppTaskStatus.Todo,
                PriorityId = taskPriorityId,
                DueDate = taskDueDate
            };
            var response = await client.PostAsJsonAsync("Task", dto);
            if (response.IsSuccessStatusCode)
            {
                CloseTaskModal();
                await LoadTasks();
                selectedProjectId = taskProjectId;
                project = projects.FirstOrDefault(p => p.Id == selectedProjectId);
                successMessage = "Task created successfully!";
            }
            else
            {
                taskError = "Failed to create task.";
            }
        }
        catch (Exception ex)
        {
            taskError = ex.Message;
        }
        finally
        {
            isSaving = false;
        }
    }

    private void RequestArchiveDoneConfirmation()
    {
        var doneCount = VisibleTasks.Count(t => t.StatusId == AppTaskStatus.Done);
        if (doneCount == 0)
        {
            successMessage = "No Done tasks to archive.";
            return;
        }

        confirmTitle = "Archive Done Tasks?";
        confirmMessage = selectedProjectId > 0
            ? $"Archive {doneCount} Done task(s) in this project? Archived tasks will be hidden from active views."
            : $"Archive {doneCount} Done task(s) across all visible projects? Archived tasks will be hidden from active views.";
        confirmButtonText = "Archive";
        confirmIcon = "archive";
        confirmIconBg = "bg-slate-100";
        confirmIconText = "text-slate-600";
        confirmButtonClass = "bg-slate-900 hover:bg-slate-800";
        confirmAction = ArchiveDoneTasks;
        showConfirmDialog = true;
    }

    private async Task ArchiveDoneTasks()
    {
        var client = ApiClient.CreateClient();
        boardError = null;

        var url = selectedProjectId > 0
            ? $"Task/archive-done?projectId={selectedProjectId}"
            : "Task/archive-done";

        try
        {
            var response = await client.PatchAsync(url, null);
            var result = await response.Content.ReadFromJsonAsync<Result<int>>(Serialization.CaseInsensitive);
            if (response.IsSuccessStatusCode && result?.IsSuccess == true)
            {
                await LoadTasks();
                successMessage = result.Value == 1
                    ? "Archived 1 Done task."
                    : $"Archived {result?.Value ?? 0} Done tasks.";
                return;
            }

            boardError = result?.ErrorMessage ?? "Failed to archive Done tasks.";
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Archive done tasks error: {ex.Message}");
            boardError = "Failed to archive Done tasks.";
        }
    }

    private string GetPriorityBadge(TaskPriority priorityId) => priorityId switch
    {
        TaskPriority.Low => "bg-slate-100 text-slate-600",
        TaskPriority.Medium => "bg-amber-100 text-amber-700",
        TaskPriority.High => "bg-red-100 text-red-700",
        _ => "bg-slate-100 text-slate-600"
    };

    private string GetPriorityLabel(TaskPriority priorityId) => priorityId switch
    {
        TaskPriority.Low => "Low",
        TaskPriority.Medium => "Medium",
        TaskPriority.High => "High",
        _ => "-"
    };

    private record KanbanColumn(AppTaskStatus StatusId, string Name, string DotColor);
}