using System.Text.Json;
using Journal.Core.Dtos;
using Journal.Core.Models;

namespace Journal.Core.Services;

public sealed class PythonSidecarSpeechService : ISpeechBridgeService
{
    private readonly PythonSidecarClient _client;

    public PythonSidecarSpeechService(JournalConfig config)
    {
        if (string.IsNullOrWhiteSpace(config.PythonAiSidecarPath))
            throw new ArgumentException("Python sidecar path is required.");
        if (!File.Exists(config.PythonAiSidecarPath))
            throw new FileNotFoundException($"Python sidecar not found: {config.PythonAiSidecarPath}");
        _client = new PythonSidecarClient(config);
    }

    public async Task<SpeechDevicesResultDto> ListDevicesAsync(CancellationToken cancellationToken = default)
    {
        var data = await _client.SendAsync("speech.devices.list", new { }, cancellationToken);
        if (data is null || data.Value.ValueKind != JsonValueKind.Object)
            return new SpeechDevicesResultDto([], "Unexpected speech device response from Python sidecar.");

        var warning = data.Value.TryGetProperty("warning", out var warningNode)
            ? warningNode.GetString()
            : null;

        var devices = new List<SpeechDeviceDto>();
        if (data.Value.TryGetProperty("devices", out var devicesNode) && devicesNode.ValueKind == JsonValueKind.Array)
        {
            foreach (var device in devicesNode.EnumerateArray())
            {
                if (device.ValueKind != JsonValueKind.Object)
                    continue;

                var index = device.TryGetProperty("index", out var indexNode) && indexNode.ValueKind == JsonValueKind.Number
                    ? indexNode.GetInt32()
                    : -1;
                var name = device.TryGetProperty("name", out var nameNode)
                    ? nameNode.GetString() ?? ""
                    : "";
                devices.Add(new SpeechDeviceDto(index, name));
            }
        }

        return new SpeechDevicesResultDto(devices, warning);
    }

    public async Task<SpeechTranscribeResultDto> TranscribeAsync(
        SpeechTranscribeRequestDto request,
        CancellationToken cancellationToken = default)
    {
        ArgumentNullException.ThrowIfNull(request);

        var data = await _client.SendAsync("speech.transcribe", new
        {
            audio_base64 = request.AudioBase64,
            engine = request.Engine,
            whisper_model = request.WhisperModel,
            text = request.Text,
            simulate_delay_ms = request.SimulateDelayMs
        }, cancellationToken);

        if (data is null || data.Value.ValueKind != JsonValueKind.Object)
            throw new InvalidOperationException("Python sidecar speech response must be a JSON object.");

        var text = data.Value.TryGetProperty("text", out var textNode)
            ? textNode.GetString() ?? ""
            : "";
        var engine = data.Value.TryGetProperty("engine", out var engineNode)
            ? engineNode.GetString() ?? (request.Engine ?? "whisper")
            : (request.Engine ?? "whisper");
        var warning = data.Value.TryGetProperty("warning", out var warningNode)
            ? warningNode.GetString()
            : null;
        return new SpeechTranscribeResultDto(text, engine, warning);
    }
}