package graders_test

import (
	"context"
	"errors"
	"slices"
	"strings"
	"testing"

	"git.golem15.com/golem15/sm-quizzes-plugin/graders"
)

type fake struct{ code, label string }

func (f fake) Code() string  { return f.code }
func (f fake) Label() string { return f.label }
func (f fake) Grade(context.Context, graders.Input) (graders.Result, error) {
	return graders.Result{}, nil
}

func TestGradersRegistry(t *testing.T) {
	reg := graders.NewRegistry()
	if got := reg.Codes(); !slices.Equal(got, []string{graders.Manual}) {
		t.Fatalf("empty Codes = %v, want [manual]", got)
	}
	if err := reg.Add("acme.one", fake{"x", "X grader"}); err != nil {
		t.Fatal(err)
	}
	if got := reg.Codes(); !slices.Equal(got, []string{graders.Manual, "x"}) {
		t.Errorf("Codes = %v, want [manual x]", got)
	}
	if g, ok := reg.Get("x"); !ok || g.Code() != "x" {
		t.Errorf("Get(x) = %v, %v", g, ok)
	}
	for _, code := range []string{graders.Manual, "zzz", ""} {
		if _, ok := reg.Get(code); ok {
			t.Errorf("Get(%q) = true, want false", code)
		}
	}
	if id, ok := reg.PluginID("x"); !ok || id != "acme.one" {
		t.Errorf("PluginID(x) = %q, %v", id, ok)
	}

	err := reg.Add("acme.two", fake{"x", "Other"})
	if !errors.Is(err, graders.ErrDuplicateCode) || !strings.Contains(err.Error(), "acme.one") || !strings.Contains(err.Error(), "acme.two") {
		t.Errorf("duplicate Add = %v, want ErrDuplicateCode naming both plugins", err)
	}
	if err := reg.Add("acme.two", fake{graders.Manual, "M"}); !errors.Is(err, graders.ErrReservedCode) {
		t.Errorf("manual Add = %v, want ErrReservedCode", err)
	}
	for _, g := range []graders.Grader{nil, fake{"", "E"}, fake{"Bad Code", "B"}, fake{"9lives", "N"}, fake{strings.Repeat("a", 65), "L"}} {
		if err := reg.Add("acme.two", g); err == nil {
			t.Errorf("Add(%v) = nil, want an error", g)
		}
	}
	if got := reg.Codes(); !slices.Equal(got, []string{graders.Manual, "x"}) {
		t.Errorf("rejected Adds changed Codes: %v", got)
	}

	opts := reg.Options()
	want := []graders.Option{{Code: graders.Manual, Label: graders.ManualLabel}, {Code: "x", Label: "X grader"}}
	if !slices.Equal(opts, want) {
		t.Errorf("Options = %v, want %v", opts, want)
	}

	var none *graders.Registry
	if got := none.Codes(); !slices.Equal(got, []string{graders.Manual}) {
		t.Errorf("nil Codes = %v", got)
	}
	if _, ok := none.Get("x"); ok {
		t.Error("nil Get = true")
	}
	if got := none.Options(); len(got) != 1 || got[0].Code != graders.Manual {
		t.Errorf("nil Options = %v", got)
	}
	if err := none.Add("acme.one", fake{"y", "Y"}); err == nil {
		t.Error("nil Add = nil, want an error")
	}
}