package main

import (
	"encoding/json"
	"errors"
	"time"
)

var PongSecret = "felixfixit"

func init() {
	router.GET("/api/students/:sid/ping", apiHandler(studentHandler(lastPing)))
	router.GET("/api/students/:sid/pong", apiHandler(studentHandler(func (student Student, body []byte) (interface{}, error) {
		return student.lastPongs()
	})))
	router.POST("/api/students/:sid/pong", apiHandler(studentHandler(stdPong), sslOnly))
}

func lastPing(student Student, body []byte) (interface{}, error) {
	if pongs, err := student.lastPongs(); err != nil {
		return nil, err
	} else if len(pongs) <= 0 {
		return false, nil
	} else {
		return pongs[0], nil
	}
}

type Pong struct {
	Date  time.Time
	State bool
}

func (s Student) lastPongs() (pongs []Pong, err error) {
	if rows, errr := DBQuery("SELECT time, state FROM student_pong WHERE id_student = ? ORDER BY time DESC", s.Id); errr != nil {
		return nil, errr
	} else {
		defer rows.Close()

		for rows.Next() {
			var p Pong
			if err = rows.Scan(&p.Date, &p.State); err != nil {
				return
			}
			pongs = append(pongs, p)
		}
		if err = rows.Err(); err != nil {
			return
		}

		return
	}
}

func stdPong(student Student, body []byte) (interface{}, error) {
	var gt givenToken
	if err := json.Unmarshal(body, &gt); err != nil {
		return nil, err
	}

	if gt.Token != PongSecret {
		return nil, errors.New("This is not the expected token.")
	}


	if res, err := DBExec("INSERT INTO student_pong (id_student, time, state) VALUES (?, ?, ?)", student.Id, time.Now(), gt.Challenge == 0); err != nil {
		return false, err
	} else if _, err := res.LastInsertId(); err != nil {
		return false, err
	} else {
		return true, err
	}
}