using System.Net.Http.Headers;
using System.Net.Http.Json;
using System.Text.Json;
using System.Text.Json.Nodes;
using Nexus.Api.Models;

namespace Nexus.Api.Services;

public sealed class OpenClawGatewayClient(HttpClient httpClient, IConfiguration configuration)
{
    private static readonly JsonSerializerOptions JsonOptions = new()
    {
        PropertyNameCaseInsensitive = true,
        PropertyNamingPolicy = JsonNamingPolicy.CamelCase
    };

    private string? GetPassword()
    {
        var password = configuration["Integrations:OpenClaw:Password"];
        if (string.IsNullOrWhiteSpace(password))
            password = configuration["Integrations:OpenClaw:Token"];
        return string.IsNullOrWhiteSpace(password) ? null : password;
    }

    private void ApplyAuth(HttpRequestMessage request)
    {
        var password = GetPassword();
        if (password is not null)
            request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", password);
    }

    public async Task<JsonNode?> InvokeToolAsync(string tool, object? args = null)
    {
        try
        {
            using var request = new HttpRequestMessage(HttpMethod.Post, "/tools/invoke");
            ApplyAuth(request);

            var body = new Dictionary<string, object?> { ["tool"] = tool };
            if (args is not null)
                body["args"] = args;

            request.Content = JsonContent.Create(body);

            using var response = await httpClient.SendAsync(request);
            if (!response.IsSuccessStatusCode)
                return null;

            var json = await response.Content.ReadAsStringAsync();
            if (string.IsNullOrWhiteSpace(json))
                return null;

            var node = JsonNode.Parse(json);
            // Unwrap the { ok: true, result: ... } envelope
            if (node?["ok"]?.GetValue<bool>() == true && node["result"] is not null)
                return node["result"];
            return node;
        }
        catch
        {
            return null;
        }
    }

    /// <summary>
    /// Extracts useful data from a tool response that may embed JSON in content[0].text.
    /// Returns the unwrapped "details" object if present, otherwise the raw result.
    /// </summary>
    private static JsonNode? ExtractToolData(JsonNode? result)
    {
        if (result is null) return null;
        // Some tools return { details: {...}, content: [...] }
        if (result["details"] is JsonNode details && details is not JsonValue)
            return details;
        // Some tools wrap in content[0].text as JSON string
        if (result["content"] is JsonArray content && content.Count > 0)
        {
            var text = content[0]?["text"]?.GetValue<string>();
            if (!string.IsNullOrWhiteSpace(text))
            {
                try { return JsonNode.Parse(text); }
                catch { /* fall through */ }
            }
        }
        return result;
    }

    public async Task<List<DashboardAgentInfo>> GetAgentsAsync()
    {
        var agents = new List<DashboardAgentInfo>();
        var seenIds = new HashSet<string>(StringComparer.OrdinalIgnoreCase);

        // Get sessions list
        var sessionsResult = await InvokeToolAsync("sessions_list");
        var sessionsData = ExtractToolData(sessionsResult);

        if (sessionsData is JsonObject so)
        {
            // sessions_list returns { agents: [...], sessions: {...} }
            // Try agents array first (from gateway call)
            if (so["agents"] is JsonArray agentArray)
            {
                foreach (var a in agentArray)
                {
                    if (a is null) continue;
                    var id = a["agentId"]?.GetValue<string>() ?? "";
                    if (string.IsNullOrWhiteSpace(id) || !seenIds.Add(id)) continue;
                    var name = a["name"]?.GetValue<string>() ?? id;
                    var model = "GPT-5.4"; // default, overridden if available
                    var isActive = false;
                    var currentTask = (string?)null;

                    // Check if agent has recent sessions (active indicator)
                    if (a["sessions"] is JsonObject sess && sess["recent"] is JsonArray recent && recent.Count > 0)
                    {
                        var age = recent[0]?["age"]?.GetValue<long>() ?? long.MaxValue;
                        isActive = age < 300_000; // active if session < 5 min ago
                        currentTask = recent[0]?["key"]?.GetValue<string>();
                    }

                    agents.Add(new DashboardAgentInfo(id, name, DeriveRole(id), model, isActive, currentTask));
                }
            }
        }

        // Also get subagents list
        var subResult = await InvokeToolAsync("subagents", new { action = "list" });
        var subData = ExtractToolData(subResult);

        if (subData is JsonArray subArray)
        {
            foreach (var s in subArray)
            {
                if (s is null) continue;
                var id = s["id"]?.GetValue<string>() ?? s["agentId"]?.GetValue<string>() ?? "";
                if (string.IsNullOrWhiteSpace(id) || !seenIds.Add(id)) continue;
                var name = s["name"]?.GetValue<string>() ?? id;
                var status = s["status"]?.GetValue<string>() ?? "";
                var isActive = status is "active" or "running";
                var currentTask = s["task"]?.GetValue<string>() ?? s["currentTask"]?.GetValue<string>();

                agents.Add(new DashboardAgentInfo(id, name, DeriveRole(id), "", isActive, currentTask));
            }
        }

        return agents;
    }

    public async Task<List<MessageEntry>> GetSessionHistoryAsync(string sessionKey, int limit = 50, int offset = 0)
    {
        try
        {
            var result = await InvokeToolAsync("sessions_history", new { sessionKey, limit, offset });
            if (result is null) return new List<MessageEntry>();

            var messages = new List<MessageEntry>();
            var array = result as JsonArray ?? result.AsArray();
            if (array is null) return messages;

            foreach (var msg in array)
            {
                if (msg is null) continue;
                var role = msg["role"]?.GetValue<string>() ?? "";
                var content = msg["content"]?.GetValue<string>() ?? "";
                var timestamp = msg["timestamp"]?.GetValue<string>()
                    ?? msg["ts"]?.GetValue<string>()
                    ?? msg["createdAt"]?.GetValue<string>()
                    ?? DateTimeOffset.UtcNow.ToString("o");

                messages.Add(new MessageEntry(role, content, timestamp));
            }

            return messages;
        }
        catch
        {
            return new List<MessageEntry>();
        }
    }

    public async Task<ChatResponse> SendChatMessageAsync(string sessionKey, string message)
    {
        try
        {
            var result = await InvokeToolAsync("sessions_send", new { sessionKey, message });
            if (result is null) return new ChatResponse(false, null, "Gateway nicht erreichbar");

            var ok = result["ok"]?.GetValue<bool>() ?? false;
            var reply = result["reply"]?.GetValue<string>()
                ?? result["response"]?.GetValue<string>()
                ?? result["content"]?[0]?["text"]?.GetValue<string>();
            var error = result["error"]?.GetValue<string>();

            return new ChatResponse(ok, reply, error);
        }
        catch (Exception ex)
        {
            return new ChatResponse(false, null, $"Fehler: {ex.Message}");
        }
    }

    public async Task<List<QueueItem>> GetQueueAsync()
    {
        try
        {
            var result = await InvokeToolAsync("cron", new { action = "list" });
            var data = ExtractToolData(result);
            if (data is null) return new List<QueueItem>();

            var items = new List<QueueItem>();
            var jobs = data["jobs"] as JsonArray ?? data.AsArray();
            if (jobs is null) return items;

            foreach (var j in jobs)
            {
                if (j is null) continue;
                var id = j["id"]?.GetValue<string>() ?? "";
                var name = j["name"]?.GetValue<string>() ?? id;
                var status = j["state"]?["lastStatus"]?.GetValue<string>()
                    ?? j["status"]?.GetValue<string>()
                    ?? "unknown";

                items.Add(new QueueItem(id, name, status));
            }
            return items;
        }
        catch
        {
            return new List<QueueItem>();
        }
    }

    public async Task<DashboardStatus> GetStatusAsync()
    {
        var gatewayOk = false;
        var irisStatus = "Offline";
        var activeAgents = 0;
        var pendingTasks = 0;

        // Step 1: Health check (no auth needed)
        try
        {
            using var pingRequest = new HttpRequestMessage(HttpMethod.Get, "/health");
            using var pingResponse = await httpClient.SendAsync(pingRequest);
            gatewayOk = pingResponse.IsSuccessStatusCode;
        }
        catch
        {
            // gatewayOk stays false
        }

        if (gatewayOk)
        {
            // Step 2: Session status
            try
            {
                var sessionResult = await InvokeToolAsync("session_status");
                if (sessionResult is not null)
                {
                    irisStatus = sessionResult["status"]?.GetValue<string>()
                        ?? sessionResult["sessionKey"]?.GetValue<string>()
                        ?? "Active";
                }
            }
            catch { }

            // Step 3: Active agents
            try
            {
                var agents = await GetAgentsAsync();
                activeAgents = agents.Count(a => a.IsActive);
            }
            catch { }

            // Step 4: Queue items
            try
            {
                var queue = await GetQueueAsync();
                pendingTasks = queue.Count;
            }
            catch { }
        }

        return new DashboardStatus(gatewayOk, irisStatus, activeAgents, pendingTasks);
    }

    private static string DeriveRole(string agentId) => agentId.ToLowerInvariant() switch
    {
        "iris" => "Orchestrator",
        "programmer" => "Developer",
        "reviewer" => "Reviewer",
        "architekt" => "Architect",
        "executor" => "Executor",
        "researcher" => "Researcher",
        "main" => "Assistant",
        _ => "Custom"
    };
}