package models

import (
	"crypto/sha256"
	"encoding/json"
	"fmt"
	"strings"
)

type Exam struct {
	Meta

	Participant *Participant `json:"participant"`
	Quizzes     []*Quiz      `json:"quizzes"`
}

func (e *Exam) String() string {
	return fmt.Sprintf("Exam ID %v with %v quizzes.", e.ID, len(e.Quizzes))
}

func (e *Exam) GetHash() string {
	qHashes := ""
	for _, q := range e.Quizzes {
		qHashes += q.GetHash()
	}
	return fmt.Sprintf("%x", sha256.Sum256([]byte(strings.Join([]string{e.Participant.GetHash(), qHashes}, ""))))
}

func (e *Exam) Marshal() ([]byte, error) {
	return json.Marshal(e)

}

func (e *Exam) Unmarshal(data []byte) error {
	return json.Unmarshal(data, e)
}

func (e *Exam) ToMarkdown() (string, error) {
	result := ""
	for _, quiz := range e.Quizzes {
		quizMD, err := QuizToMarkdown(quiz)
		if err != nil {
			return "", err
		}
		result += fmt.Sprintf(quizMD)
		result += "\n"
	}

	return strings.TrimRight(fmt.Sprintf("# %s %s \n %s", e.Participant.Lastname, e.Participant.Firstname, result), "\n"), nil
}