package web

import (
	"bytes"
	"encoding/binary"
	"io"
	"log/slog"
	"net/http"
	"net/http/httptest"
	"net/url"
	"strings"
	"testing"
	"time"

	"gitea.mynodes.xyz/ilker/llmgw/internal/hf"
	"gitea.mynodes.xyz/ilker/llmgw/internal/store"
)

// ggufServer serves a GGUF whose header names an architecture.
func ggufServer(t *testing.T, arch string) string {
	t.Helper()
	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(2))
	str("general.architecture")
	w(uint32(8))
	str(arch)
	str("general.name")
	w(uint32(8))
	str("m")
	body := b.Bytes()
	srv := httptest.NewServer(http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
		http.ServeContent(rw, r, "m.gguf", time.Time{}, bytes.NewReader(body))
	}))
	t.Cleanup(srv.Close)
	return srv.URL + "/m.gguf"
}

func mirrorPageLlama(t *testing.T, d MirrorDeps) *http.ServeMux {
	t.Helper()
	a := fakeAccounts{user: store.User{ID: "u1", Email: "a@example.com", IsAdmin: true}}
	p := NewAccountPages(a, nil, nil, "v0", slog.New(slog.NewTextHandler(io.Discard, nil)))
	p.SetLlamaCppVersion("b10991")
	mux := http.NewServeMux()
	p.RegisterAdminMirror(mux, d)
	return mux
}

// The file that started this: kev-0.5b, architecture "ggmlc", downloaded,
// catalogued, and refused by llama.cpp on every node it was placed on.
func TestAFileTheNodesCannotLoadIsNotFetched(t *testing.T) {
	m := &fakeMirror{}
	mux := mirrorPageLlama(t, MirrorDeps{Mirror: m})
	src := ggufServer(t, "ggmlc")

	body := mirrorPost(t, mux, "/admin/mirror/fetch", url.Values{"csrf": {"tok"},
		"source": {src}, "model": {"kev"}, "version": {"v1"}}).Body.String()
	if len(m.all) != 0 {
		t.Fatal("a file llama.cpp cannot load was sent to the mirror")
	}
	if !strings.Contains(body, "ggmlc") || !strings.Contains(body, "cannot load") {
		t.Errorf("the refusal should say why; got %s", body)
	}

	// Asked for regardless, it is fetched.
	mirrorPost(t, mux, "/admin/mirror/fetch", url.Values{"csrf": {"tok"},
		"source": {src}, "model": {"kev"}, "version": {"v1"}, "force": {"1"}})
	if len(m.all) != 1 {
		t.Error("fetch anyway did not fetch")
	}

	// And one it can load goes straight through.
	m.all = nil
	mirrorPost(t, mux, "/admin/mirror/fetch", url.Values{"csrf": {"tok"},
		"source": {ggufServer(t, "qwen2")}, "model": {"q"}, "version": {"v1"}})
	if len(m.all) != 1 {
		t.Error("a qwen2 GGUF was refused")
	}
}

func TestTheRegistryListingSaysWhatCannotBeServed(t *testing.T) {
	reg := &fakeRegistry{repo: hf.Repo{ID: "someone/kev-gguf", Revision: "abc12345", Architecture: "ggmlc",
		Files: []hf.File{{Path: "kev-q4_k_m.gguf", Bytes: 500 << 20}}}}
	body := mirrorGet(t, mirrorPageLlama(t, MirrorDeps{Mirror: &fakeMirror{}, Registry: reg}),
		"/admin/mirror?q=kev&repo=someone/kev-gguf").Body.String()
	if !strings.Contains(body, "cannot be served") {
		t.Error("the listing does not say the file cannot be served")
	}
	if strings.Contains(body, `value="`+"https://huggingface.co") && strings.Contains(body, ">Fetch</button>") {
		t.Error("the listing still offers to fetch it")
	}
}