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

namespace AxCopilot.Services.Agent;

public sealed class EnterWorktreeTool : IAgentTool
{
    public string Name => "enter_worktree";
    public string Description => "Enter or create a nested worktree path inside current WorkFolder.";

    public ToolParameterSchema Parameters => new()
    {
        Properties = new()
        {
            ["path"] = new() { Type = "string", Description = "Relative worktree path." },
            ["create"] = new() { Type = "boolean", Description = "Create directory if missing (default true)." }
        },
        Required = ["path"]
    };

    public Task<ToolResult> ExecuteAsync(JsonElement args, AgentContext context, CancellationToken ct = default)
    {
        var relative = args.TryGetProperty("path", out var pathEl) ? (pathEl.GetString() ?? "").Trim() : "";
        if (string.IsNullOrWhiteSpace(relative))
            return Task.FromResult(ToolResult.Fail("path is required."));
        if (string.IsNullOrWhiteSpace(context.WorkFolder) || !Directory.Exists(context.WorkFolder))
            return Task.FromResult(ToolResult.Fail("valid WorkFolder is required."));

        var create = !args.TryGetProperty("create", out var createEl) || createEl.ValueKind != JsonValueKind.False;
        var root = WorktreeStateStore.ResolveRoot(context.WorkFolder);
        var full = Path.GetFullPath(Path.Combine(root, relative));
        if (!full.StartsWith(root, StringComparison.OrdinalIgnoreCase))
            return Task.FromResult(ToolResult.Fail("worktree path must stay inside WorkFolder."));

        if (!Directory.Exists(full))
        {
            if (!create)
                return Task.FromResult(ToolResult.Fail("worktree path does not exist."));
            Directory.CreateDirectory(full);
        }

        var state = WorktreeStateStore.Load(root);
        state.Active = full;
        WorktreeStateStore.Save(root, state);
        context.WorkFolder = full;
        return Task.FromResult(ToolResult.Ok($"Entered worktree: {full}"));
    }
}