package oci

import (
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"testing"
)

func TestCatalog(t *testing.T) {
	fdb := newFakeDB()
	fdb.addRepo("alpha/lib", 1)
	fdb.addRepo("bravo/svc", 2)
	fdb.addRepo("charlie/app", 3)

	h := NewHandler(fdb, newFakeBlobs(), allowAll(), nil, nil)
	router := testRouter(h)

	req := authedRequest("GET", "/v2/_catalog", nil)
	rr := httptest.NewRecorder()
	router.ServeHTTP(rr, req)

	if rr.Code != http.StatusOK {
		t.Fatalf("status: got %d, want %d", rr.Code, http.StatusOK)
	}

	var body catalogResponse
	if err := json.NewDecoder(rr.Body).Decode(&body); err != nil {
		t.Fatalf("decode body: %v", err)
	}

	want := []string{"alpha/lib", "bravo/svc", "charlie/app"}
	if len(body.Repositories) != len(want) {
		t.Fatalf("repos count: got %d, want %d", len(body.Repositories), len(want))
	}
	for i, r := range body.Repositories {
		if r != want[i] {
			t.Fatalf("repos[%d]: got %q, want %q", i, r, want[i])
		}
	}
}

func TestCatalogPagination(t *testing.T) {
	fdb := newFakeDB()
	fdb.addRepo("alpha/lib", 1)
	fdb.addRepo("bravo/svc", 2)
	fdb.addRepo("charlie/app", 3)

	h := NewHandler(fdb, newFakeBlobs(), allowAll(), nil, nil)
	router := testRouter(h)

	// First page: n=2.
	req := authedRequest("GET", "/v2/_catalog?n=2", nil)
	rr := httptest.NewRecorder()
	router.ServeHTTP(rr, req)

	if rr.Code != http.StatusOK {
		t.Fatalf("status: got %d, want %d", rr.Code, http.StatusOK)
	}

	var body catalogResponse
	if err := json.NewDecoder(rr.Body).Decode(&body); err != nil {
		t.Fatalf("decode body: %v", err)
	}
	if len(body.Repositories) != 2 {
		t.Fatalf("page 1 count: got %d, want 2", len(body.Repositories))
	}
	if body.Repositories[0] != "alpha/lib" || body.Repositories[1] != "bravo/svc" {
		t.Fatalf("page 1: got %v", body.Repositories)
	}

	// Check Link header.
	link := rr.Header().Get("Link")
	if link == "" {
		t.Fatal("expected Link header for pagination")
	}

	// Second page: n=2, last=bravo/svc.
	req = authedRequest("GET", "/v2/_catalog?n=2&last=bravo/svc", nil)
	rr = httptest.NewRecorder()
	router.ServeHTTP(rr, req)

	if rr.Code != http.StatusOK {
		t.Fatalf("page 2 status: got %d, want %d", rr.Code, http.StatusOK)
	}

	if err := json.NewDecoder(rr.Body).Decode(&body); err != nil {
		t.Fatalf("decode page 2: %v", err)
	}
	if len(body.Repositories) != 1 {
		t.Fatalf("page 2 count: got %d, want 1", len(body.Repositories))
	}
	if body.Repositories[0] != "charlie/app" {
		t.Fatalf("page 2: got %v", body.Repositories)
	}

	// No Link header on last page.
	if link := rr.Header().Get("Link"); link != "" {
		t.Fatalf("expected no Link header on last page, got %q", link)
	}
}

func TestCatalogEmpty(t *testing.T) {
	fdb := newFakeDB()

	h := NewHandler(fdb, newFakeBlobs(), allowAll(), nil, nil)
	router := testRouter(h)

	req := authedRequest("GET", "/v2/_catalog", nil)
	rr := httptest.NewRecorder()
	router.ServeHTTP(rr, req)

	if rr.Code != http.StatusOK {
		t.Fatalf("status: got %d, want %d", rr.Code, http.StatusOK)
	}

	var body catalogResponse
	if err := json.NewDecoder(rr.Body).Decode(&body); err != nil {
		t.Fatalf("decode body: %v", err)
	}
	if len(body.Repositories) != 0 {
		t.Fatalf("expected empty repositories, got %v", body.Repositories)
	}
}