using MAF1.Agents.FileCity;
using Microsoft.Agents.AI.Workflows;
using Microsoft.Extensions.AI;

namespace MAF1.Workflows;

internal sealed class CityGateExecutor() : ChatProtocolExecutor(
    "CityGate",
    new ChatProtocolExecutorOptions { AutoSendTurnToken = false })
{
    protected override ProtocolBuilder ConfigureProtocol(ProtocolBuilder builder)
    {
        return base.ConfigureProtocol(builder)
            .SendsMessage<ChatMessage>()
            .SendsMessage<TurnToken>()
            .YieldsOutput<string>();
    }

    protected override async ValueTask TakeTurnAsync(
        List<ChatMessage> messages,
        IWorkflowContext context,
        bool? emitEvents,
        CancellationToken cancellationToken)
    {
        string text = string.Join(
            Environment.NewLine,
            messages
                .Where(message => !string.IsNullOrWhiteSpace(message.Text))
                .Select(message => message.Text));

        CityExtraction extraction = FileCityAgent.Parse(text);
        if (!extraction.HasValidCities)
        {
            string reason = string.IsNullOrWhiteSpace(extraction.Reason)
                ? "文件里没有可查询的城市。"
                : extraction.Reason;
            await context.YieldOutputAsync(
                $"没有有效城市，工作流结束，不执行 WeatherAgent。{reason}",
                cancellationToken);
            return;
        }

        string prompt = $"请查询这些城市的天气：{string.Join("、", extraction.Cities)}";
        await context.SendMessageAsync(new ChatMessage(ChatRole.User, prompt), cancellationToken: cancellationToken);
        await context.SendMessageAsync(new TurnToken(emitEvents), cancellationToken: cancellationToken);
    }
}