using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Net.Http.Json;
using System.Text.Json;
using System.Threading.Tasks;
using System.Text.Json.Serialization;

namespace finder2e_foundry_converter.Services
{
    public class LlmService
    {
        private readonly HttpClient _httpClient = new HttpClient();

        public async Task<List<string>> GetModelsAsync(string baseUrl)
        {
            try
            {
                var response = await _httpClient.GetFromJsonAsync<ModelsResponse>($"{baseUrl.TrimEnd('/')}/v1/models");
                if (response?.Data == null) return new List<string>();

                var models = new List<string>();
                foreach (var model in response.Data)
                {
                    models.Add(model.Id);
                }
                return models;
            }
            catch
            {
                return new List<string> { "Error: LM Studio not found" };
            }
        }

        public async Task<string> GenerateResponseAsync(string baseUrl, string model, string text, List<string> imagePaths)
        {
            try
            {
                var contents = new List<object>
                {
                    new { type = "text", text = text }
                };

                foreach (var path in imagePaths)
                {
                    if (string.IsNullOrWhiteSpace(path)) continue;

                    var bytes = await System.IO.File.ReadAllBytesAsync(path);
                    var base64 = Convert.ToBase64String(bytes);
                    var extension = System.IO.Path.GetExtension(path).ToLower();
                    var mimeType = extension switch
                    {
                        ".jpg" or ".jpeg" => "image/jpeg",
                        ".webp" => "image/webp",
                        _ => "image/png"
                    };

                    contents.Add(new
                    {
                        type = "image_url",
                        image_url = new { url = $"data:{mimeType};base64,{base64}" }
                    });
                }

                var requestBody = new
                {
                    model = model,
                    messages = new[]
                    {
                        new { role = "user", content = contents }
                    }
                };

                var response = await _httpClient.PostAsJsonAsync($"{baseUrl.TrimEnd('/')}/v1/chat/completions", requestBody);
                var body = await response.Content.ReadAsStringAsync();

                using var doc = JsonDocument.Parse(body);
                if (doc.RootElement.TryGetProperty("error", out var error))
                {
                    return $"Error: {error.GetProperty("message").GetString()}";
                }

                if (doc.RootElement.TryGetProperty("choices", out var choices) && choices.GetArrayLength() > 0)
                {
                    return choices[0].GetProperty("message").GetProperty("content").GetString() ?? "No content returned";
                }

                return "No response choices returned.";
            }
            catch (Exception ex)
            {
                return $"Error: {ex.Message}";
            }
        }

        private class ModelsResponse
        {
            [JsonPropertyName("data")]
            public List<ModelData>? Data { get; set; }
        }

        private class ModelData
        {
            [JsonPropertyName("id")]
            public string Id { get; set; } = string.Empty;
        }
    }
}