using Docker.DotNet;
using Docker.DotNet.Models;
using CaddyManager.Contracts.Configurations.Docker;
using CaddyManager.Contracts.Configurations;
using CaddyManager.Contracts.Docker;

namespace CaddyManager.Services.Docker;

/// <inheritdoc />
public class DockerService(IConfigurationsService configurationsService) : IDockerService
{
    private DockerServiceConfiguration Configuration => configurationsService.Get<DockerServiceConfiguration>();

    /// <summary>
    /// Method to get the container id of the Caddy container by the name configured
    /// </summary>
    /// <returns></returns>
    private async Task<string> GetCaddyContainerId(IDockerClient client)
    {
        var containers = await client.Containers.ListContainersAsync(new ContainersListParameters
        {
            All = true
        });

        return containers.FirstOrDefault(container => container.Names.Contains($"/{Configuration.CaddyContainerName}"))
            ?.ID ?? string.Empty;

    }

    private IDockerClient CreateClient() =>
        new DockerClientConfiguration(new Uri(Configuration.DockerHostWithEnvCheck)).CreateClient();

    /// <inheritdoc />
    public async Task RestartCaddyContainerAsync()
    {
        using var client = CreateClient();

        var containerId = await GetCaddyContainerId(client);

        if (string.IsNullOrEmpty(containerId)) return;

        await client.Containers.RestartContainerAsync(containerId, new ContainerRestartParameters());
    }

    /// <inheritdoc />
    public async Task<CaddyReloadResponse> ReloadCaddyContainerAsync()
    {
        try
        {
            using var client = CreateClient();

            var containerId = await GetCaddyContainerId(client);

            if (string.IsNullOrEmpty(containerId))
            {
                return new CaddyReloadResponse
                {
                    Message = $"Caddy container '{Configuration.CaddyContainerName}' was not found"
                };
            }

            var exec = await client.Exec.ExecCreateContainerAsync(containerId, new ContainerExecCreateParameters
            {
                Cmd = ["caddy", "reload", "--config", Configuration.CaddyConfigPathInContainer],
                AttachStdout = true,
                AttachStderr = true
            });

            string stdout, stderr;

            using (var stream = await client.Exec.StartAndAttachContainerExecAsync(exec.ID, false))
            {
                (stdout, stderr) = await stream.ReadOutputToEndAsync(CancellationToken.None);
            }

            var inspection = await client.Exec.InspectContainerExecAsync(exec.ID);

            if (inspection.ExitCode == 0)
            {
                return new CaddyReloadResponse { Success = true };
            }

            // Caddy reports errors on stderr, interleaved with its structured JSON progress logs which are noise here
            var output = string.Join(Environment.NewLine, $"{stderr}{Environment.NewLine}{stdout}"
                .Split('\n', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries)
                .Where(line => !line.StartsWith('{')));

            return new CaddyReloadResponse
            {
                Message = string.IsNullOrWhiteSpace(output)
                    ? $"Caddy reload failed with exit code {inspection.ExitCode}"
                    : output.Trim()
            };
        }
        catch (Exception e)
        {
            return new CaddyReloadResponse { Message = e.Message };
        }
    }
}