package api

import (
	"encoding/json"
	"strings"
	"testing"
	"time"

	"git.golem15.com/golem15/sm-quizzes-plugin/classes"
	"git.golem15.com/golem15/sm-quizzes-plugin/models"
	"git.golem15.com/golem15/summercms/modules/lagoon"
)

// fixtureQuestion is a question of type typ with every solution field set,
// so a serializer that forgets to drop one shows it.
func fixtureQuestion(id uint, typ string) models.Question {
	expl, model, why := "question explanation", "model answer", "answer explanation"
	q := models.Question{ID: id, Text: "Q", Type: typ, Points: 2, Explanation: &expl, AnswerText: &model}
	if typ != models.TypeSelfCheck {
		q.Answers = []models.Answer{
			{ID: id*10 + 1, QuestionID: id, Text: "right", IsCorrect: true, Explanation: &why},
			{ID: id*10 + 2, QuestionID: id, Text: "wrong", Explanation: &why},
		}
	}
	return q
}

func decode(t *testing.T, v any) (map[string]any, string) {
	t.Helper()
	b, err := json.Marshal(v)
	if err != nil {
		t.Fatal(err)
	}
	var out map[string]any
	if err := json.Unmarshal(b, &out); err != nil {
		t.Fatal(err)
	}
	return out, string(b)
}

// noSolution fails when any solution key of m (a feedback or a result
// question) holds a value.
func noSolution(t *testing.T, where string, m map[string]any, keys ...string) {
	t.Helper()
	for _, k := range keys {
		v, ok := m[k]
		if !ok {
			t.Errorf("%s: key %s missing", where, k)
			continue
		}
		if v != nil {
			t.Errorf("%s: %s = %v, want null", where, k, v)
		}
	}
	answers, _ := m["answers"].([]any)
	for i, raw := range answers {
		a := raw.(map[string]any)
		if a["is_correct"] != nil || a["explanation"] != nil {
			t.Errorf("%s: answers[%d] = %v, want no is_correct or explanation", where, i, a)
		}
		if a["id"] == nil || a["text"] == nil {
			t.Errorf("%s: answers[%d] lost its id or text: %v", where, i, a)
		}
	}
}

func noCorrectness(t *testing.T, where, raw string) {
	t.Helper()
	if strings.Contains(raw, `"is_correct":true`) || strings.Contains(raw, `"is_correct":false`) {
		t.Errorf("%s reveals correctness: %s", where, raw)
	}
}

func TestWithheldSerializers(t *testing.T) {
	for _, typ := range models.QuestionTypes {
		t.Run(typ, func(t *testing.T) {
			answered, unanswered := fixtureQuestion(1, typ), fixtureQuestion(2, typ)
			test := &models.Quiz{Slug: "t", PassingScore: 50, Mode: models.ModeTest}

			fb := &classes.Feedback{
				Question:         answered,
				Result:           classes.ScoreResult{IsCorrect: true, Points: 2},
				CorrectAnswerIDs: classes.CorrectAnswerIDs(answered),
				Withheld:         true,
			}
			m, raw := decode(t, feedback(fb))
			if m["withheld"] != true {
				t.Errorf("feedback withheld = %v, want true", m["withheld"])
			}
			noSolution(t, "feedback", m, "is_correct", "points", "correct_answer_ids", "explanation", "answer_text")
			noCorrectness(t, "feedback", raw)
			if typ != models.TypeSelfCheck && len(m["answers"].([]any)) != 2 {
				t.Errorf("feedback answers = %v, want both answers", m["answers"])
			}

			known := true
			row := &models.AttemptAnswer{AttemptID: 5, QuestionID: 1, IsCorrect: true, Points: 2}
			if typ == models.TypeSelfCheck {
				row.SelfCheckKnown = &known
			} else {
				row.AnswerIDs = lagoon.Jsonable[[]uint]{Data: []uint{11}, Valid: true}
			}
			res := &classes.AttemptResult{
				AttemptSummary: classes.AttemptSummary{Attempt: models.Attempt{ID: 5, QuizID: 3, StartedAt: time.Now(), Quiz: test}, AnsweredCount: 1},
				Questions:      []classes.QuestionResult{{Question: answered, Answer: row}, {Question: unanswered}},
			}
			m, raw = decode(t, result(res))
			if m["solutions_withheld"] != true || m["quiz_mode"] != models.ModeTest {
				t.Errorf("result solutions_withheld = %v quiz_mode = %v", m["solutions_withheld"], m["quiz_mode"])
			}
			noCorrectness(t, "result", raw)
			questions := m["questions"].([]any)
			if len(questions) != 2 {
				t.Fatalf("result questions = %d, want 2", len(questions))
			}
			for i, raw := range questions {
				q := raw.(map[string]any)
				noSolution(t, "result question "+string(rune('0'+i)), q, "is_correct", "points_earned", "correct_answer_ids", "explanation", "answer_text")
			}
			first := questions[0].(map[string]any)
			if first["answered"] != true {
				t.Errorf("answered question lost answered: %v", first)
			}
			if typ == models.TypeSelfCheck {
				if first["known"] != true {
					t.Errorf("self_check lost the student's known: %v", first)
				}
			} else if ids, _ := first["answer_ids"].([]any); len(ids) != 1 || ids[0] != float64(11) {
				t.Errorf("answer_ids = %v, want the student's [11]", first["answer_ids"])
			}

			done := time.Now()
			res.Attempt.CompletedAt = &done
			m, _ = decode(t, result(res))
			if m["solutions_withheld"] != false {
				t.Errorf("completed test still withheld")
			}
			for _, raw := range m["questions"].([]any) {
				q := raw.(map[string]any)
				if q["is_correct"] == nil || q["points_earned"] == nil || q["explanation"] == nil || q["correct_answer_ids"] == nil {
					t.Errorf("completed test hides a solution: %v", q)
				}
			}
		})
	}
}

func TestLearningFeedbackUnchanged(t *testing.T) {
	q := fixtureQuestion(1, models.TypeSingle)
	fb := &classes.Feedback{Question: q, Result: classes.ScoreResult{IsCorrect: false, Points: 0}, CorrectAnswerIDs: classes.CorrectAnswerIDs(q)}
	m, raw := decode(t, feedback(fb))
	if m["withheld"] != false {
		t.Errorf("withheld = %v, want false", m["withheld"])
	}
	if m["is_correct"] != false || m["points"] != float64(0) {
		t.Errorf("is_correct / points = %v / %v, want false / 0", m["is_correct"], m["points"])
	}
	if ids, ok := m["correct_answer_ids"].([]any); !ok || len(ids) != 1 {
		t.Errorf("correct_answer_ids = %v, want [11]", m["correct_answer_ids"])
	}
	if !strings.Contains(raw, `"is_correct":true`) || m["explanation"] == nil || m["answer_text"] == nil {
		t.Errorf("learning feedback lost a solution: %s", raw)
	}

	res := &classes.AttemptResult{
		AttemptSummary: classes.AttemptSummary{Attempt: models.Attempt{ID: 5, StartedAt: time.Now(), Quiz: &models.Quiz{Slug: "s", PassingScore: 50}}},
		Questions:      []classes.QuestionResult{{Question: q}},
	}
	m, _ = decode(t, result(res))
	row := m["questions"].([]any)[0].(map[string]any)
	if m["solutions_withheld"] != false || m["quiz_mode"] != models.ModeLearning || m["quiz_navigation"] != models.NavigationFree {
		t.Errorf("learning result flags = %v %v %v", m["solutions_withheld"], m["quiz_mode"], m["quiz_navigation"])
	}
	if row["is_correct"] != false || row["points_earned"] != float64(0) {
		t.Errorf("unanswered learning question = %v / %v, want false / 0", row["is_correct"], row["points_earned"])
	}
}

func TestTestQuizDetailHidesQuestions(t *testing.T) {
	d := &classes.QuizDetail{
		Quiz:      models.Quiz{Slug: "t", Mode: models.ModeTest, Navigation: models.NavigationOneWay},
		Questions: []models.Question{fixtureQuestion(1, models.TypeSelfCheck), fixtureQuestion(2, models.TypeSingle)},
	}
	m, raw := decode(t, quizDetail(d))
	if qs, ok := m["questions"].([]any); !ok || len(qs) != 0 {
		t.Errorf("test detail questions = %v, want []", m["questions"])
	}
	if m["question_count"] != float64(2) || m["mode"] != models.ModeTest || m["navigation"] != models.NavigationOneWay {
		t.Errorf("test detail = %s", raw)
	}
	if strings.Contains(raw, "model answer") {
		t.Errorf("test detail leaks answer_text: %s", raw)
	}

	d.Quiz.Mode = models.ModeLearning
	m, _ = decode(t, quizDetail(d))
	if qs, _ := m["questions"].([]any); len(qs) != 2 {
		t.Errorf("learning detail questions = %d, want 2", len(qs))
	}
}