using MeetingAssistant.LaunchProfiles;
using Microsoft.Extensions.Options;

namespace MeetingAssistant.Transcription;

public sealed class ConfiguredSpeechRecognitionPipelineFactory : ISpeechRecognitionPipelineFactory
{
    private readonly IReadOnlyDictionary<string, ISpeechRecognitionPipelineBuilder> builders;
    private readonly MeetingAssistantOptions options;
    private readonly ILaunchProfileOptionsProvider? launchProfiles;

    public ConfiguredSpeechRecognitionPipelineFactory(
        IEnumerable<ISpeechRecognitionPipelineBuilder> builders,
        IOptions<MeetingAssistantOptions> options)
        : this(builders, options, launchProfiles: null)
    {
    }

    public ConfiguredSpeechRecognitionPipelineFactory(
        IEnumerable<ISpeechRecognitionPipelineBuilder> builders,
        IOptions<MeetingAssistantOptions> options,
        ILaunchProfileOptionsProvider? launchProfiles)
    {
        this.options = options.Value;
        this.launchProfiles = launchProfiles;
        this.builders = builders
            .GroupBy(builder => builder.ProviderName, StringComparer.OrdinalIgnoreCase)
            .ToDictionary(
                group => group.Key,
                group => group.Count() == 1
                    ? group.Single()
                    : throw new InvalidOperationException(
                        $"Speech recognition pipeline provider '{group.Key}' is registered more than once."),
                StringComparer.OrdinalIgnoreCase);
        if (this.builders.Count == 0)
        {
            throw new InvalidOperationException("No speech recognition pipeline builders are registered.");
        }
    }

    public ISpeechRecognitionPipeline Create()
    {
        return Create(null);
    }

    public ISpeechRecognitionPipeline Create(string? launchProfileName)
    {
        var profileOptions = ResolveOptions(launchProfileName);
        if (!builders.TryGetValue(profileOptions.Recording.TranscriptionProvider, out var builder))
        {
            throw new InvalidOperationException(
                $"Unsupported speech recognition pipeline '{profileOptions.Recording.TranscriptionProvider}'.");
        }

        return builder.Create(profileOptions);
    }

    private MeetingAssistantOptions ResolveOptions(string? launchProfileName)
    {
        if (launchProfiles is not null)
        {
            return launchProfiles.GetRequiredProfile(launchProfileName).Options;
        }

        if (string.IsNullOrWhiteSpace(launchProfileName) ||
            launchProfileName.Equals(ConfigurationLaunchProfileOptionsProvider.DefaultProfileName, StringComparison.OrdinalIgnoreCase))
        {
            return options;
        }

        throw new InvalidOperationException(
            $"Launch profile '{launchProfileName}' was requested, but no launch profile provider is registered.");
    }

}