using System.IO;
using System.Linq;
using System.Text;
using System.Text.Json;

namespace AxCopilot.Services.Agent;

public sealed class TaskListTool : IAgentTool
{
    public string Name => "task_list";

    public string Description => "List tasks from the workspace task board.";

    public ToolParameterSchema Parameters => new()
    {
        Properties = new()
        {
            ["status"] = new() { Type = "string", Description = "Filter by status (optional)." }
        },
        Required = []
    };

    public Task<ToolResult> ExecuteAsync(JsonElement args, AgentContext context, CancellationToken ct = default)
    {
        if (string.IsNullOrWhiteSpace(context.WorkFolder) || !Directory.Exists(context.WorkFolder))
            return Task.FromResult(ToolResult.Fail("valid WorkFolder is required."));

        var status = args.SafeTryGetProperty("status", out var statusEl) ? (statusEl.SafeGetString() ?? "").Trim().ToLowerInvariant() : "";
        var tasks = TaskBoardStore.Load(context.WorkFolder);
        if (!string.IsNullOrWhiteSpace(status))
            tasks = tasks.Where(t => string.Equals(t.Status, status, StringComparison.OrdinalIgnoreCase)).ToList();

        if (tasks.Count == 0)
            return Task.FromResult(ToolResult.Ok("No tasks."));

        var ordered = tasks
            .OrderBy(t => t.Status == "done" || t.Status == "stopped" ? 1 : 0)
            .ThenByDescending(t => t.Priority == "high" ? 3 : t.Priority == "medium" ? 2 : 1)
            .ThenByDescending(t => t.UpdatedAt)
            .ToList();

        var sb = new StringBuilder();
        sb.AppendLine($"tasks: {ordered.Count}");
        foreach (var t in ordered)
            sb.AppendLine($"#{t.Id} [{t.Status}] [{t.Priority}] {t.Title}");
        return Task.FromResult(ToolResult.Ok(sb.ToString()));
    }
}