import { Task, TaskStatus } from "@/model/task";
import { IConfigProvider, ITaskRepository } from "@/ports";
import * as vscode from "vscode";

const STATUS_ORDER: TaskStatus[] = ["todo", "in-progress", "done", "cancelled"];

const STATUS_ICONS: Record<TaskStatus, vscode.ThemeIcon> = {
	todo: new vscode.ThemeIcon("circle-outline"),
	"in-progress": new vscode.ThemeIcon("sync"),
	done: new vscode.ThemeIcon("check"),
	cancelled: new vscode.ThemeIcon("close"),
};

class TaskGroupTreeItem extends vscode.TreeItem {
	readonly tasks: Task[];

	constructor(label: string, tasks: Task[], icon: vscode.ThemeIcon) {
		super(label, vscode.TreeItemCollapsibleState.Collapsed);
		this.iconPath = icon;
		this.tasks = tasks;
		this.description = `(${tasks.length})`;
	}
}

export class TaskTreeProvider implements vscode.TreeDataProvider<vscode.TreeItem> {
	#onDidChangeTreeData = new vscode.EventEmitter<
		vscode.TreeItem | undefined | null | void
	>();
	readonly onDidChangeTreeData = this.#onDidChangeTreeData.event;

	#taskStore: ITaskRepository;
	#configStore: IConfigProvider;

	constructor(taskStore: ITaskRepository, configStore: IConfigProvider) {
		this.#taskStore = taskStore;
		this.#configStore = configStore;
	}

	refresh(): void {
		this.#onDidChangeTreeData.fire();
	}

	getTreeItem(element: vscode.TreeItem): vscode.TreeItem {
		return element;
	}

	async getChildren(element?: vscode.TreeItem): Promise<vscode.TreeItem[]> {
		if (!element) {
			return this.getRootChildren();
		}
		return this.getTaskChildren(element as TaskGroupTreeItem);
	}

	private async getRootChildren(): Promise<vscode.TreeItem[]> {
		const projectPath = this.#configStore.getProjectTaskPath();
		if (!projectPath) {
			return [new vscode.TreeItem("Open a workspace folder to start")];
		}

		const tasks = await this.#taskStore.list(projectPath);

		return STATUS_ORDER.map((status) => {
			const groupTasks = tasks.filter((t) => t.status === status);
			const label =
				status === "todo"
					? "To Do"
					: status === "in-progress"
						? "In Progress"
						: status === "done"
							? "Done"
							: "Cancelled";
			const item = new TaskGroupTreeItem(
				label,
				groupTasks,
				STATUS_ICONS[status],
			);
			item.id = `group-${status}`;
			item.contextValue = "taskGroup";
			return item;
		});
	}

	private getTaskChildren(group: TaskGroupTreeItem): vscode.TreeItem[] {
		return group.tasks.map((task) => {
			const item = new vscode.TreeItem(task.title);
			item.id = task.id;
			item.description = task.priority;
			item.tooltip = new vscode.MarkdownString(
				`**${task.title}**\n\nPriority: ${task.priority}\nStatus: ${task.status}${task.assignee ? `\nAssignee: ${task.assignee}` : ""}`,
			);
			item.contextValue = "task";
			return item;
		});
	}
}