using System.Text;
using System.Text.Encodings.Web;
using System.Text.Json;
using Microsoft.Agents.AI;
using Microsoft.Agents.AI.Workflows;
using Microsoft.Extensions.AI;

namespace MAF1.Route;

/// <summary>
/// 跑 Handoff。工具日志按 callId 去重：同一调用会同时出现在流式事件、完整回复、结束输出里，只打一遍。
/// </summary>
public static class HandoffRun
{
    private static readonly JsonSerializerOptions JsonOptions = new()
    {
        Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping,
    };

    public static async Task RunAsync(Workflow workflow, string task)
    {
        HashSet<string> printedCalls = new(StringComparer.Ordinal);
        List<ChatMessage> messages = [new(ChatRole.User, task)];
        await using StreamingRun run = await InProcessExecution.RunStreamingAsync(workflow, messages);
        await run.TrySendMessageAsync(new TurnToken(emitEvents: true));

        string? lastExecutorId = null;
        string? lastSummary = null;
        await foreach (WorkflowEvent evt in run.WatchStreamAsync())
        {
            switch (evt)
            {
                case ExecutorFailedEvent failed:
                    Console.WriteLine();
                    Console.WriteLine($"[失败] {failed.ExecutorId}: {failed.Data}");
                    break;

                case AgentResponseUpdateEvent update:
                    if (update.ExecutorId != lastExecutorId)
                    {
                        Console.WriteLine();
                        Console.Write($"{Friendly(update.ExecutorId)}: ");
                        lastExecutorId = update.ExecutorId;
                    }

                    if (!string.IsNullOrEmpty(update.Update.Text))
                    {
                        Console.Write(update.Update.Text);
                    }

                    WriteNewTools(update.ExecutorId, update.Update.Contents, printedCalls);
                    break;

                case WorkflowOutputEvent output:
                    string? summary = ReadSummary(output);
                    if (!string.IsNullOrWhiteSpace(summary) && summary != lastSummary)
                    {
                        lastSummary = summary;
                        Console.WriteLine();
                        Console.WriteLine();
                        Console.WriteLine($"[最终输出] {Trim(summary)}");
                    }

                    break;
            }
        }

        Console.WriteLine();
        Console.WriteLine("======== Handoff 本轮结束 ========");
    }

    private static void WriteNewTools(string executorId, IList<AIContent> contents, HashSet<string> printedCalls)
    {
        foreach (AIContent content in contents)
        {
            if (content is FunctionCallContent call)
            {
                string key = "call:" + (string.IsNullOrWhiteSpace(call.CallId) ? call.Name + FormatArguments(call.Arguments) : call.CallId);
                if (!printedCalls.Add(key))
                {
                    continue;
                }

                Console.WriteLine();
                Console.WriteLine($"[工具调用] {Friendly(executorId)} → {call.Name}");
                Console.WriteLine($"          参数: {FormatArguments(call.Arguments)}");
                continue;
            }

            if (content is FunctionResultContent result)
            {
                string key = "result:" + result.CallId;
                if (!printedCalls.Add(key))
                {
                    continue;
                }

                Console.WriteLine();
                Console.WriteLine($"[工具返回] {Friendly(executorId)} → {result.CallId}");
                Console.WriteLine($"          结果: {Trim(FormatResult(result.Result))}");
            }
        }
    }

    private static string? ReadSummary(WorkflowOutputEvent output)
    {
        if (output.As<List<ChatMessage>>() is List<ChatMessage> chat)
        {
            return LastAssistantText(chat);
        }

        return output.As<string>();
    }

    private static string FormatArguments(IDictionary<string, object?>? arguments)
    {
        if (arguments is null || arguments.Count == 0)
        {
            return "{}";
        }

        try
        {
            return JsonSerializer.Serialize(arguments, JsonOptions);
        }
        catch
        {
            return string.Join(", ", arguments.Select(kv => $"{kv.Key}={kv.Value}"));
        }
    }

    private static string FormatResult(object? result)
        => result is null ? "(空)" : result.ToString() ?? "(空)";

    private static string LastAssistantText(List<ChatMessage> chat)
    {
        string text = "";
        foreach (ChatMessage message in chat)
        {
            if (message.Role == ChatRole.Assistant && !string.IsNullOrWhiteSpace(message.Text))
            {
                text = message.Text;
            }
        }

        return text;
    }

    private static string Friendly(string executorId)
    {
        int us = executorId.IndexOf('_');
        if (us > 0 && executorId[(us + 1)..] == executorId[..us])
        {
            return executorId[..us];
        }

        return executorId;
    }

    private static string Trim(string text)
    {
        string oneLine = text.Replace("\r\n", " ").Replace('\n', ' ').Trim();
        return oneLine.Length <= 500 ? oneLine : oneLine[..500] + "…";
    }
}