using System;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;
using Newtonsoft.Json.Linq;
using SwarmUI.Accounts;
using SwarmUI.Utils;

namespace Mrleo1nid.SwarmAssistent;

/// <summary>VRAM handover between Ollama and the image backend: park the chat model before
/// Generate, warm it again once the user is back in the chat. Embed / memory models are never
/// parked — they are tiny and reloading them stalls every retrieve.</summary>
public partial class SwarmAssistentExtension
{
    const string WarmKeepAlive = "15m";

    /// <summary>Unloads the chat model from VRAM (<c>keep_alive: 0</c>) so Krea 2 gets the whole GPU.</summary>
    public async Task<JObject> AssistentParkLlm(Session session, string baseUrl, string model)
    {
        string root = NormalizeBaseUrl(baseUrl);
        string name = (model ?? "").Trim();
        if (string.IsNullOrWhiteSpace(name))
        {
            return new JObject { ["error"] = "model is required" };
        }
        if (LooksLikeEmbedModel(name))
        {
            return new JObject { ["success"] = true, ["parked"] = false, ["skipped"] = "memory model — never parked" };
        }
        JObject generate = new()
        {
            ["model"] = name,
            ["prompt"] = "",
            ["stream"] = false,
            ["keep_alive"] = 0,
        };
        (bool ok, string body) = await PostOllamaJson(root, "/api/generate", generate);
        if (!ok)
        {
            // Older Ollama builds only unload through /api/chat.
            JObject chat = new()
            {
                ["model"] = name,
                ["messages"] = new JArray(),
                ["stream"] = false,
                ["keep_alive"] = 0,
            };
            (ok, body) = await PostOllamaJson(root, "/api/chat", chat);
        }
        if (!ok)
        {
            Logs.Debug($"AssistentParkLlm {name}: {Clip(body, 200)}");
            return new JObject { ["success"] = true, ["parked"] = false, ["note"] = Clip(body, 200) };
        }
        return new JObject { ["success"] = true, ["parked"] = true, ["model"] = name, ["base_url"] = root };
    }

    /// <summary>Single-token chat so the model is resident again by the time the user types.</summary>
    public async Task<JObject> AssistentWarmLlm(Session session, string baseUrl, string model)
    {
        string root = NormalizeBaseUrl(baseUrl);
        string name = (model ?? "").Trim();
        if (string.IsNullOrWhiteSpace(name))
        {
            return new JObject { ["error"] = "model is required" };
        }
        if (LooksLikeEmbedModel(name))
        {
            return new JObject { ["success"] = true, ["warmed"] = false, ["skipped"] = "memory model" };
        }
        int numCtx = CfgInt("num_ctx", DefaultNumCtxFallback);
        JObject payload = new()
        {
            ["model"] = name,
            ["stream"] = false,
            ["messages"] = new JArray
            {
                new JObject { ["role"] = "user", ["content"] = "ok" },
            },
            ["options"] = new JObject
            {
                ["num_ctx"] = numCtx,
                ["num_predict"] = 1,
            },
            ["keep_alive"] = WarmKeepAlive,
        };
        (bool ok, string body) = await PostOllamaJson(root, "/api/chat", payload);
        if (!ok)
        {
            Logs.Debug($"AssistentWarmLlm {name}: {Clip(body, 200)}");
            return new JObject { ["success"] = true, ["warmed"] = false, ["note"] = Clip(body, 200) };
        }
        return new JObject
        {
            ["success"] = true,
            ["warmed"] = true,
            ["model"] = name,
            ["num_ctx"] = numCtx,
            ["keep_alive"] = WarmKeepAlive,
        };
    }

    static async Task<(bool ok, string body)> PostOllamaJson(string root, string route, JObject payload)
    {
        try
        {
            using StringContent content = new(payload.ToString(Newtonsoft.Json.Formatting.None), Encoding.UTF8, "application/json");
            using HttpResponseMessage resp = await HttpClient.PostAsync($"{root}{route}", content);
            string body = await resp.Content.ReadAsStringAsync();
            return (resp.IsSuccessStatusCode, resp.IsSuccessStatusCode ? body : $"HTTP {(int)resp.StatusCode}: {body}");
        }
        catch (Exception ex)
        {
            return (false, ex.Message);
        }
    }
}