using System.Text.Json;
using Agent.Core.Ollama;
using Agent.Core.Runtime;
using Agent.Core.Tools;

namespace Agent.App.Logging;

public sealed class JsonLinesRuntimeObserver(string logDirectory) : IAgentRuntimeObserver
{
    private readonly object _sync = new();
    private readonly string _path = Path.Combine(logDirectory, "llm.jsonl");

    public void LlmRequest(Guid taskId, int iteration, IReadOnlyList<OllamaMessage> messages) => Write(new
    {
        timestamp = DateTimeOffset.UtcNow, task_id = taskId, event_name = "llm.request", iteration,
        messages = messages.Select(static message => new { message.Role, message.Content, image_count = message.Images?.Count ?? 0, message.ToolName })
    });

    public void LlmResponse(Guid taskId, int iteration, OllamaResult result) => Write(new
    {
        timestamp = DateTimeOffset.UtcNow, task_id = taskId, event_name = "llm.response", iteration,
        result.Content, input_tokens = result.InputTokens, output_tokens = result.OutputTokens,
        tool_calls = result.ToolCalls?.Select(static call => call.Function.Name).ToArray() ?? []
    });

    public void ToolResult(Guid taskId, string toolName, ToolExecutionResult result) => Write(new
    {
        timestamp = DateTimeOffset.UtcNow, task_id = taskId, event_name = "llm.tool_result", tool_name = toolName,
        result.Success, result.ExternalEffect, result.RetryAllowed, result.Output, result.FailureFingerprint
    });

    private void Write(object value)
    {
        string line = JsonSerializer.Serialize(value);
        lock (_sync) File.AppendAllText(_path, line + Environment.NewLine);
    }
}