using System.Text;
using System.Text.Json;
using AxCopilot.Models;

namespace AxCopilot.Services.Agent;

/// <summary>
/// P5: 배치 서브에이전트 생성 도구.
/// 여러 서브에이전트를 한 번에 생성하고 통합 결과를 반환합니다.
/// </summary>
public class SpawnAgentsTool : IAgentTool
{
    public string Name => "spawn_agents";

    public string Description =>
        "Create multiple sub-agents in batch for parallel research or task execution.\n" +
        "Each agent runs independently with its own task and optional profile.\n" +
        "Collect results later with wait_agents.";

    public ToolParameterSchema Parameters => new()
    {
        Properties = new()
        {
            ["agents"] = new ToolProperty
            {
                Type = "array",
                Description = "List of sub-agent definitions. Each has: id (unique identifier), task (work description), profile (optional: researcher/coder/writer/reviewer/planner).",
                Items = new ToolProperty
                {
                    Type = "object",
                    Description = "Sub-agent definition with id, task, and optional profile."
                }
            },
        },
        Required = new() { "agents" }
    };

    public async Task<ToolResult> ExecuteAsync(JsonElement args, AgentContext context, CancellationToken ct = default)
    {
        if (!args.SafeTryGetProperty("agents", out var agentsEl) || agentsEl.ValueKind != JsonValueKind.Array)
            return ToolResult.Fail("agents array is required.");

        var agentDefs = new List<(string Id, string Task, string? Profile)>();
        foreach (var item in agentsEl.EnumerateArray())
        {
            var id = item.SafeTryGetProperty("id", out var idEl) ? idEl.SafeGetString() ?? "" : "";
            var task = item.SafeTryGetProperty("task", out var taskEl) ? taskEl.SafeGetString() ?? "" : "";
            var profile = item.SafeTryGetProperty("profile", out var profEl) ? profEl.SafeGetString() : null;

            if (string.IsNullOrWhiteSpace(id) || string.IsNullOrWhiteSpace(task))
                return ToolResult.Fail($"Each agent must have non-empty 'id' and 'task'. Found invalid entry.");

            agentDefs.Add((id, task, profile));
        }

        if (agentDefs.Count == 0)
            return ToolResult.Fail("agents array is empty.");

        // 용량 사전 검증 (빠른 실패용 — 실제 원자성은 SubAgentTool.ExecuteAsync 내부 lock에서 보장)
        var app = System.Windows.Application.Current as App;
        var maxAgents = app?.SettingsService?.Settings.Llm.MaxSubAgents ?? 5;
        var activeTasks = SubAgentTool.ActiveTasks;
        var running = activeTasks.Values.Count(x => x.CompletedAt == null);

        if (running + agentDefs.Count > maxAgents)
            return ToolResult.Fail(
                $"Cannot spawn {agentDefs.Count} agents: {running} already running, max is {maxAgents}.");

        // 중복 ID 검사
        var duplicateIds = agentDefs.GroupBy(a => a.Id, StringComparer.OrdinalIgnoreCase)
            .Where(g => g.Count() > 1)
            .Select(g => g.Key)
            .ToList();
        if (duplicateIds.Count > 0)
            return ToolResult.Fail($"Duplicate agent ids: {string.Join(", ", duplicateIds)}");

        // 기존 활성 태스크와 ID 충돌 검사
        var conflictIds = agentDefs.Where(a => activeTasks.ContainsKey(a.Id)).Select(a => a.Id).ToList();
        if (conflictIds.Count > 0)
            return ToolResult.Fail($"Agent ids already exist: {string.Join(", ", conflictIds)}");

        // 각 에이전트를 SubAgentTool을 통해 생성
        var spawnTool = new SubAgentTool();
        var results = new List<(string Id, bool Success, string Message)>();
        var cancelled = false;

        foreach (var (id, task, profile) in agentDefs)
        {
            // 루프 중 취소 감지 — 이미 생성된 에이전트는 유지하고 나머지만 건너뜀
            if (ct.IsCancellationRequested)
            {
                cancelled = true;
                results.Add((id, false, "Cancelled: batch spawn interrupted."));
                continue;
            }

            // SubAgentTool.ExecuteAsync용 JsonElement 구성
            var jsonObj = new Dictionary<string, object?>
            {
                ["id"] = id,
                ["task"] = task,
            };
            if (!string.IsNullOrWhiteSpace(profile))
                jsonObj["profile"] = profile;

            var jsonStr = JsonSerializer.Serialize(jsonObj);
            using var doc = JsonDocument.Parse(jsonStr);

            var result = await spawnTool.ExecuteAsync(doc.RootElement, context, ct).ConfigureAwait(false);
            results.Add((id, result.Success, result.Output ?? ""));
        }

        // 통합 결과 메시지
        var sb = new StringBuilder();
        var successCount = results.Count(r => r.Success);
        var failCount = results.Count(r => !r.Success);

        sb.AppendLine($"Batch spawn: {successCount} started, {failCount} failed (total: {agentDefs.Count}){(cancelled ? " [partially cancelled]" : "")}");
        sb.AppendLine();

        foreach (var (id, success, message) in results)
        {
            var status = success ? "✓" : "✗";
            var profileName = agentDefs.First(a => a.Id == id).Profile ?? "researcher";
            sb.AppendLine($"{status} [{id}] profile={profileName}");
            if (!success)
                sb.AppendLine($"  Error: {message}");
        }

        sb.AppendLine();
        sb.AppendLine("Use wait_agents to collect results when ready.");

        return failCount == agentDefs.Count
            ? ToolResult.Fail(sb.ToString().TrimEnd())
            : ToolResult.Ok(sb.ToString().TrimEnd());
    }
}