package adminapi

import (
	"bytes"
	"encoding/binary"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	"gitea.mynodes.xyz/ilker/llmgw/internal/control/catalog"
)

// ggufStart is the start of a GGUF file with these string keys.
func ggufStart(kv ...string) []byte {
	var b bytes.Buffer
	w := func(v any) { _ = binary.Write(&b, binary.LittleEndian, v) }
	str := func(s string) { w(uint64(len(s))); b.WriteString(s) }
	b.WriteString("GGUF")
	w(uint32(3))
	w(uint64(0))
	w(uint64(len(kv) / 2))
	for i := 0; i < len(kv); i += 2 {
		str(kv[i])
		w(uint32(8)) // string
		str(kv[i+1])
	}
	b.Write(make([]byte, 4096))
	return b.Bytes()
}

func TestOnlyAnAdapterForTheModelsArchitectureIsAttached(t *testing.T) {
	files := map[string][]byte{
		"/base.gguf":  ggufStart("general.architecture", "qwen2"),
		"/model.gguf": ggufStart("general.architecture", "qwen2", "general.type", "model"),
		"/llama.gguf": ggufStart("general.architecture", "llama", "general.type", "adapter"),
		"/lora.gguf":  ggufStart("general.architecture", "qwen2", "general.type", "adapter"),
	}
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusPartialContent)
		_, _ = w.Write(files[r.URL.Path])
	}))
	defer srv.Close()

	models := []catalog.Model{{
		Name: "coder", Source: srv.URL + "/base.gguf",
		Scaling:  catalog.Scaling{Min: 1, Max: 1},
		Profiles: []catalog.Profile{{Name: "cpu", Engine: "llamacpp", MinMemoryGB: 8}},
	}}
	for _, tc := range []struct {
		file, want string
		code       int
	}{
		{"/model.gguf", "not a LoRA adapter", http.StatusBadRequest},
		{"/llama.gguf", "for llama models", http.StatusBadRequest},
		{"/lora.gguf", "", http.StatusOK},
	} {
		a, _ := setup(t, models)
		fm := &fakeModels{}
		a.SetModels(fm)
		mux := http.NewServeMux()
		a.Register(mux)
		req := httptest.NewRequest(http.MethodPost, "/api/v1/models/coder/adapters",
			strings.NewReader(`{"adapters":[{"name":"fix","source":"`+srv.URL+tc.file+`"}]}`))
		rec := httptest.NewRecorder()
		mux.ServeHTTP(rec, req)
		if rec.Code != tc.code || !strings.Contains(rec.Body.String(), tc.want) {
			t.Errorf("%s: %d %s; want %d mentioning %q", tc.file, rec.Code, rec.Body.String(), tc.code, tc.want)
		}
	}
}