using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.Serialization;

namespace Prophet.CoopWithDsh
{
    [DataContract]
    internal sealed class OpenDocument
    {
        [DataMember(Name = "path", Order = 1)] public string Path { get; set; } = string.Empty;
        [DataMember(Name = "label", Order = 2)] public string Label { get; set; } = string.Empty;
        [DataMember(Name = "dirty", Order = 3)] public bool Dirty { get; set; }
    }

    [DataContract]
    internal sealed class OpenFileSnapshot
    {
        [DataMember(Name = "version", Order = 1)] public int Version { get; set; } = 1;
        [DataMember(Name = "instanceId", Order = 2)] public string InstanceId { get; set; } = string.Empty;
        [DataMember(Name = "ide", Order = 3)] public string Ide { get; set; } = "visualstudio";
        [DataMember(Name = "processId", Order = 4)] public int ProcessId { get; set; }
        [DataMember(Name = "workspace", Order = 5, EmitDefaultValue = false)] public string? Workspace { get; set; }
        [DataMember(Name = "updatedAt", Order = 6)] public string UpdatedAt { get; set; } = string.Empty;
        [DataMember(Name = "documents", Order = 7)] public OpenDocument[] Documents { get; set; } = Array.Empty<OpenDocument>();
    }

    internal static class SnapshotModel
    {
        internal static OpenFileSnapshot Create(string instanceId, int processId, string? workspace, IEnumerable<OpenDocument> documents, DateTimeOffset now)
        {
            var deduplicated = new Dictionary<string, OpenDocument>(StringComparer.OrdinalIgnoreCase);
            foreach (var document in documents.Where(d => !string.IsNullOrWhiteSpace(d.Path) && Path.IsPathRooted(d.Path)))
            {
                if (!deduplicated.TryGetValue(document.Path, out var current) || (!current.Dirty && document.Dirty))
                    deduplicated[document.Path] = document;
            }
            return new OpenFileSnapshot
            {
                InstanceId = instanceId,
                ProcessId = processId,
                Workspace = string.IsNullOrWhiteSpace(workspace) ? null : workspace,
                UpdatedAt = now.UtcDateTime.ToString("O"),
                Documents = deduplicated.Values.OrderBy(d => d.Label, StringComparer.OrdinalIgnoreCase).ThenBy(d => d.Path, StringComparer.OrdinalIgnoreCase).ToArray(),
            };
        }
    }
}