using System.Text.Json;
using System.Text.Json.Serialization;
using ClaudeDo.Data;

namespace ClaudeDo.Worker.Config;

public sealed class WorkerConfig
{
    [JsonPropertyName("db_path")]
    public string DbPath { get; set; } = "~/.todo-app/todo.db";

    [JsonPropertyName("sandbox_root")]
    public string SandboxRoot { get; set; } = "~/.todo-app/sandbox";

    [JsonPropertyName("log_root")]
    public string LogRoot { get; set; } = "~/.todo-app/logs";

    /// <summary>"sibling" → place worktrees next to the target repo; "central" → under <see cref="CentralWorktreeRoot"/>.</summary>
    [JsonPropertyName("worktree_root_strategy")]
    public string WorktreeRootStrategy { get; set; } = "sibling";

    [JsonPropertyName("central_worktree_root")]
    public string CentralWorktreeRoot { get; set; } = "~/.todo-app/worktrees";

    [JsonPropertyName("queue_backstop_interval_ms")]
    public int QueueBackstopIntervalMs { get; set; } = 30_000;

    [JsonPropertyName("signalr_port")]
    public int SignalRPort { get; set; } = 47_821;

    [JsonPropertyName("claude_bin")]
    public string ClaudeBin { get; set; } = "claude";

    /// <summary>Port for the external MCP endpoint. 0 disables the external listener entirely.</summary>
    [JsonPropertyName("external_mcp_port")]
    public int ExternalMcpPort { get; set; } = 47_822;

    /// <summary>Optional API key clients must pass via X-ClaudeDo-Key header. Null/empty = loopback trust only.</summary>
    [JsonPropertyName("external_mcp_api_key")]
    public string? ExternalMcpApiKey { get; set; }

    public static string DefaultConfigPath =>
        Path.Combine(Paths.AppDataRoot(), "worker.config.json");

    /// <summary>
    /// Loads the config from <paramref name="path"/> (defaults to <see cref="DefaultConfigPath"/>).
    /// Missing file → returns defaults. Resolves all path-typed fields to absolute paths.
    /// </summary>
    public static WorkerConfig Load(string? path = null)
    {
        path ??= DefaultConfigPath;

        WorkerConfig cfg;
        if (File.Exists(path))
        {
            var json = File.ReadAllText(path);
            cfg = JsonSerializer.Deserialize<WorkerConfig>(json, JsonOpts)
                ?? throw new InvalidOperationException($"Failed to parse {path}");
        }
        else
        {
            cfg = new WorkerConfig();
        }

        cfg.DbPath = Paths.Expand(cfg.DbPath);
        cfg.SandboxRoot = Paths.Expand(cfg.SandboxRoot);
        cfg.LogRoot = Paths.Expand(cfg.LogRoot);
        cfg.CentralWorktreeRoot = Paths.Expand(cfg.CentralWorktreeRoot);

        return cfg;
    }

    private static readonly JsonSerializerOptions JsonOpts = new()
    {
        ReadCommentHandling = JsonCommentHandling.Skip,
        AllowTrailingCommas = true,
    };
}