using System.Net;
using System.Net.Http.Json;
using System.Text;
using RobotNet10.CustomConfigurationEditor.Models;

namespace RobotNet10.CustomConfigurationEditor.Services.API;

/// <summary>
/// Service cho giao tiếp với Config REST API
/// </summary>
public class ConfigApiService(HttpClient httpClient)
{
    private readonly HttpClient _httpClient = httpClient;
    private readonly string? _baseUrl = httpClient.BaseAddress?.AbsoluteUri;
    private const string ApiPath = "api/configs";

    // ==========================================
    // CONFIG FILE MANAGEMENT
    // ==========================================

    /// <summary>
    /// Lấy tất cả configs (metadata only)
    /// </summary>
    public async Task<List<ConfigFileMetadataModel>> GetAllConfigsAsync(string? search = null)
    {
        var url = $"{_baseUrl}{ApiPath}";
        if (!string.IsNullOrEmpty(search))
            url += $"?search={Uri.EscapeDataString(search)}";

        return await _httpClient.GetFromJsonAsync<List<ConfigFileMetadataModel>>(url) ?? [];
    }
    
    /// <summary>
    /// Lấy config theo ID
    /// </summary>
    public async Task<ConfigFileModel?> GetConfigByIdAsync(Guid id)
    {
        return await _httpClient.GetFromJsonAsync<ConfigFileModel>($"{_baseUrl}{ApiPath}/{id}");
    }
    
    /// <summary>
    /// Lấy config theo ConfigType
    /// </summary>
    public async Task<ConfigFileModel?> GetConfigByTypeAsync(string configType)
    {
        return await _httpClient.GetFromJsonAsync<ConfigFileModel>($"{_baseUrl}{ApiPath}/by-type/{Uri.EscapeDataString(configType)}");
    }
    
    /// <summary>
    /// Kiểm tra ConfigType có tồn tại không
    /// </summary>
    public async Task<bool> ConfigTypeExistsAsync(string configType)
    {
        return await _httpClient.GetFromJsonAsync<bool>($"{_baseUrl}{ApiPath}/exists/{Uri.EscapeDataString(configType)}");
    }
    
    /// <summary>
    /// Tạo config mới
    /// </summary>
    public async Task<ConfigFileModel> CreateConfigAsync(string configType, List<ConfigVariableModel> variables, string? description = null)
    {
        var request = new
        {
            ConfigType = configType,
            Variables = variables,
            Description = description
        };
        
        var response = await _httpClient.PostAsJsonAsync($"{_baseUrl}{ApiPath}", request);
        
        if (!response.IsSuccessStatusCode)
        {
            var errorMessage = await HttpErrorHelper.GetErrorMessageAsync(response);
            throw new HttpRequestException(errorMessage);
        }
        
        return await response.Content.ReadFromJsonAsync<ConfigFileModel>() 
            ?? throw new Exception("Failed to create config. Invalid response from server.");
    }
    
    /// <summary>
    /// Cập nhật config
    /// </summary>
    public async Task<ConfigFileModel> UpdateConfigAsync(Guid id, List<ConfigVariableModel>? variables = null, string? description = null)
    {
        var request = new
        {
            Variables = variables,
            Description = description
        };
        
        var response = await _httpClient.PutAsJsonAsync($"{_baseUrl}{ApiPath}/{id}", request);
        
        if (!response.IsSuccessStatusCode)
        {
            var errorMessage = await HttpErrorHelper.GetErrorMessageAsync(response);
            throw new HttpRequestException(errorMessage);
        }
        
        return await response.Content.ReadFromJsonAsync<ConfigFileModel>() 
            ?? throw new Exception("Failed to update config. Invalid response from server.");
    }
    
    /// <summary>
    /// Xóa config
    /// </summary>
    public async Task DeleteConfigAsync(Guid id)
    {
        var response = await _httpClient.DeleteAsync($"{_baseUrl}{ApiPath}/{id}");
        
        if (!response.IsSuccessStatusCode)
        {
            var errorMessage = await HttpErrorHelper.GetErrorMessageAsync(response);
            throw new HttpRequestException(errorMessage);
        }
    }
    
    // ==========================================
    // IMPORT/EXPORT
    // ==========================================
    
    /// <summary>
    /// Import config từ JSON file
    /// </summary>
    public async Task<ConfigFileModel> ImportConfigAsync(Stream fileStream, string fileName, string configType, string? description = null)
    {
        using var content = new MultipartFormDataContent();
        var streamContent = new StreamContent(fileStream);
        streamContent.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("application/json");
        content.Add(streamContent, "file", fileName);
        content.Add(new StringContent(configType), "configType");
        if (!string.IsNullOrWhiteSpace(description))
        {
            content.Add(new StringContent(description), "description");
        }
        
        var response = await _httpClient.PostAsync($"{_baseUrl}{ApiPath}/import", content);
        
        if (!response.IsSuccessStatusCode)
        {
            var errorMessage = await HttpErrorHelper.GetErrorMessageAsync(response);
            throw new HttpRequestException(errorMessage);
        }
        
        return await response.Content.ReadFromJsonAsync<ConfigFileModel>() 
            ?? throw new Exception("Failed to import config. Invalid response from server.");
    }
    
    /// <summary>
    /// Export config ra JSON file
    /// </summary>
    public async Task<Stream> ExportConfigAsync(Guid id)
    {
        var response = await _httpClient.GetAsync($"{_baseUrl}{ApiPath}/{id}/export");
        
        if (!response.IsSuccessStatusCode)
        {
            var errorMessage = await HttpErrorHelper.GetErrorMessageAsync(response);
            throw new HttpRequestException(errorMessage);
        }
        
        try
        {
            // Read content as byte array first, then create memory stream
            var bytes = await response.Content.ReadAsByteArrayAsync();
            var memoryStream = new MemoryStream(bytes);
            memoryStream.Position = 0; // Reset position to beginning
            return memoryStream;
        }
        catch (Exception ex)
        {
            throw new HttpRequestException($"Failed to read export data: {HttpErrorHelper.GetErrorMessage(ex)}", ex);
        }
    }
    
    // ==========================================
    // VARIABLE MANAGEMENT
    // ==========================================
    
    /// <summary>
    /// Cập nhật giá trị của một variable
    /// </summary>
    public async Task<ConfigFileModel> UpdateVariableAsync(Guid configId, string variableName, object? value)
    {
        var request = new { Value = value };

        var response = await _httpClient.PutAsJsonAsync($"{_baseUrl}{ApiPath}/{configId}/variables/{Uri.EscapeDataString(variableName)}", request);
        
        if (!response.IsSuccessStatusCode)
        {
            var errorMessage = await HttpErrorHelper.GetErrorMessageAsync(response);
            throw new HttpRequestException(errorMessage);
        }
        
        return await response.Content.ReadFromJsonAsync<ConfigFileModel>() 
            ?? throw new Exception("Failed to update variable. Invalid response from server.");
    }
    
    /// <summary>
    /// Thêm variable mới vào config
    /// </summary>
    public async Task<ConfigFileModel> AddVariableAsync(Guid configId, ConfigVariableModel variable)
    {
        var response = await _httpClient.PostAsJsonAsync($"{_baseUrl}{ApiPath}/{configId}/variables", variable);
        
        if (!response.IsSuccessStatusCode)
        {
            var errorMessage = await HttpErrorHelper.GetErrorMessageAsync(response);
            throw new HttpRequestException(errorMessage);
        }
        
        return await response.Content.ReadFromJsonAsync<ConfigFileModel>() 
            ?? throw new Exception("Failed to add variable. Invalid response from server.");
    }
    
    /// <summary>
    /// Xóa variable khỏi config
    /// </summary>
    public async Task<ConfigFileModel> RemoveVariableAsync(Guid configId, string variableName)
    {
        var response = await _httpClient.DeleteAsync($"{_baseUrl}{ApiPath}/{configId}/variables/{Uri.EscapeDataString(variableName)}");
        
        if (!response.IsSuccessStatusCode)
        {
            var errorMessage = await HttpErrorHelper.GetErrorMessageAsync(response);
            throw new HttpRequestException(errorMessage);
        }
        
        return await response.Content.ReadFromJsonAsync<ConfigFileModel>() 
            ?? throw new Exception("Failed to remove variable. Invalid response from server.");
    }
}