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

namespace AxCopilot.Services.Agent;

internal static class TaskBoardStore
{
    private const string StoreRelativePath = ".ax/taskboard.json";

    internal sealed class TaskItem
    {
        [JsonPropertyName("id")]
        public int Id { get; set; }

        [JsonPropertyName("title")]
        public string Title { get; set; } = "";

        [JsonPropertyName("description")]
        public string Description { get; set; } = "";

        [JsonPropertyName("status")]
        public string Status { get; set; } = "open"; // open | in_progress | blocked | done | stopped

        [JsonPropertyName("priority")]
        public string Priority { get; set; } = "medium"; // high | medium | low

        [JsonPropertyName("output")]
        public string Output { get; set; } = "";

        [JsonPropertyName("createdAt")]
        public DateTime CreatedAt { get; set; } = DateTime.Now;

        [JsonPropertyName("updatedAt")]
        public DateTime UpdatedAt { get; set; } = DateTime.Now;
    }

    internal static string GetStorePath(string workFolder)
        => Path.Combine(workFolder, StoreRelativePath);

    internal static List<TaskItem> Load(string workFolder)
    {
        var path = GetStorePath(workFolder);
        if (!File.Exists(path))
            return [];

        try
        {
            var json = TextFileCodec.ReadAllText(path).Text;
            return JsonSerializer.Deserialize<List<TaskItem>>(json) ?? [];
        }
        catch
        {
            return [];
        }
    }

    internal static void Save(string workFolder, List<TaskItem> tasks)
    {
        var path = GetStorePath(workFolder);
        var dir = Path.GetDirectoryName(path);
        if (!string.IsNullOrWhiteSpace(dir) && !Directory.Exists(dir))
            Directory.CreateDirectory(dir);

        var json = JsonSerializer.Serialize(tasks, new JsonSerializerOptions
        {
            WriteIndented = true
        });
        File.WriteAllText(path, json, TextFileCodec.Utf8NoBom);
    }

    internal static int NextId(List<TaskItem> tasks)
        => tasks.Count == 0 ? 1 : tasks.Max(t => t.Id) + 1;

    internal static bool IsValidStatus(string value)
        => value is "open" or "in_progress" or "blocked" or "done" or "stopped";

    internal static bool IsValidPriority(string value)
        => value is "high" or "medium" or "low";
}