using System.Diagnostics;
using Microsoft.Extensions.Logging;

namespace Service.AgentFramework;

/// <summary>
/// Agent 基类 - 提供通用的工作流编排能力
/// </summary>
public abstract class BaseAgent
{
    protected readonly IToolRegistry _toolRegistry;
    protected readonly ILogger<BaseAgent> _logger;
    protected readonly List<ExecutionStep> _steps = new();
    protected readonly Dictionary<string, object?> _metadata = new();
    
    // 定义 ActivitySource 供 DevUI 捕获
    private static readonly ActivitySource _activitySource = new("Microsoft.Agents.Workflows");

    protected BaseAgent(
        IToolRegistry toolRegistry,
        ILogger<BaseAgent> logger)
    {
        _toolRegistry = toolRegistry;
        _logger = logger;
    }

    /// <summary>
    /// 记录执行步骤
    /// </summary>
    protected void RecordStep(
        string name,
        string description,
        object? output = null,
        long durationMs = 0)
    {
        var step = new ExecutionStep
        {
            Name = name,
            Description = description,
            Status = "Completed",
            Output = output,
            DurationMs = durationMs
        };

        _steps.Add(step);
        
        // 使用 Activity 进行埋点，将被 DevUI 自动捕获
        using var activity = _activitySource.StartActivity(name);
        activity?.SetTag("agent.step.description", description);
        if (output != null) activity?.SetTag("agent.step.output", output.ToString());
    }

    /// <summary>
    /// 记录失败的步骤
    /// </summary>
    protected void RecordFailedStep(
        string name,
        string description,
        string error,
        long durationMs = 0)
    {
        var step = new ExecutionStep
        {
            Name = name,
            Description = description,
            Status = "Failed",
            Error = error,
            DurationMs = durationMs
        };

        _steps.Add(step);
        
        using var activity = _activitySource.StartActivity($"{name} (Failed)");
        activity?.SetTag("agent.step.error", error);
        _logger.LogError("[Agent步骤失败] {StepName}: {Error}", name, error);
    }

    /// <summary>
    /// 设置元数据
    /// </summary>
    protected void SetMetadata(string key, object? value)
    {
        _metadata[key] = value;
    }

    /// <summary>
    /// 获取执行日志
    /// </summary>
    protected List<ExecutionStep> GetExecutionLog()
    {
        return _steps.ToList();
    }

    /// <summary>
    /// 生成多轮总结
    /// </summary>
    protected virtual async Task<string> GenerateSummaryAsync(
        string[] phases,
        Dictionary<string, object?> phaseResults)
    {
        var summaryParts = new List<string>();

        // 简单的总结生成逻辑
        // 实际项目中可以集成 AI 生成更复杂的总结
        foreach (var phase in phases)
        {
            if (phaseResults.TryGetValue(phase, out var result))
            {
                summaryParts.Add($"{phase}：已完成");
            }
        }

        return await Task.FromResult(string.Join("；", summaryParts) + "。");
    }

    /// <summary>
    /// 调用 Tool（简化接口）
    /// </summary>
    protected async Task<TResult> CallToolAsync<TResult>(
        string toolName,
        string stepName,
        string stepDescription)
    {
        var sw = System.Diagnostics.Stopwatch.StartNew();
        try
        {
            _logger.LogInformation("开始执行 Tool: {ToolName}", toolName);
            var result = await _toolRegistry.InvokeToolAsync<TResult>(toolName);
            sw.Stop();

            RecordStep(stepName, stepDescription, result, sw.ElapsedMilliseconds);
            return result;
        }
        catch (Exception ex)
        {
            sw.Stop();
            RecordFailedStep(stepName, stepDescription, ex.Message, sw.ElapsedMilliseconds);
            throw;
        }
    }

    /// <summary>
    /// 调用带参数的 Tool
    /// </summary>
    protected async Task<TResult> CallToolAsync<TParam, TResult>(
        string toolName,
        TParam param,
        string stepName,
        string stepDescription)
    {
        var sw = System.Diagnostics.Stopwatch.StartNew();
        try
        {
            _logger.LogInformation("开始执行 Tool: {ToolName}，参数: {Param}", toolName, param);
            var result = await _toolRegistry.InvokeToolAsync<TParam, TResult>(toolName, param);
            sw.Stop();

            RecordStep(stepName, stepDescription, result, sw.ElapsedMilliseconds);
            return result;
        }
        catch (Exception ex)
        {
            sw.Stop();
            RecordFailedStep(stepName, stepDescription, ex.Message, sw.ElapsedMilliseconds);
            throw;
        }
    }

    /// <summary>
    /// 调用带多参数的 Tool
    /// </summary>
    protected async Task<TResult> CallToolAsync<TParam1, TParam2, TResult>(
        string toolName,
        TParam1 param1,
        TParam2 param2,
        string stepName,
        string stepDescription)
    {
        var sw = System.Diagnostics.Stopwatch.StartNew();
        try
        {
            _logger.LogInformation("开始执行 Tool: {ToolName}，参数: {Param1}, {Param2}", toolName, param1, param2);
            var result = await _toolRegistry.InvokeToolAsync<TParam1, TParam2, TResult>(
                toolName, param1, param2);
            sw.Stop();

            RecordStep(stepName, stepDescription, result, sw.ElapsedMilliseconds);
            return result;
        }
        catch (Exception ex)
        {
            sw.Stop();
            RecordFailedStep(stepName, stepDescription, ex.Message, sw.ElapsedMilliseconds);
            throw;
        }
    }

    /// <summary>
    /// 获取 Agent 执行结果
    /// </summary>
    protected AgentResult<T> CreateResult<T>(
        T data,
        string summary,
        bool success = true,
        string? error = null)
    {
        return new AgentResult<T>
        {
            Data = data,
            Summary = summary,
            Steps = _steps,
            Metadata = _metadata,
            Success = success,
            Error = error
        };
    }
}