package main

import (
    "database/sql"
    "fmt"
    "log"
    "math/rand"
    "net/http"
    "net/url"
    "strconv"
    "strings"
    "time"

    _ "github.com/go-sql-driver/mysql"
)

type homework struct {
    id     int
    text   string
    todate string
}

type recipient struct {
    id     int
    name   string
    userID int
}

func main() {

    begin, end, err := getEndPoints()
    if err != nil {
        log.Fatal(err)
    } else {
        fmt.Println(begin, end)
        message := getHomework(begin, end)
        //fmt.Println(message)
        sendHomework(message)
    }
}

func getEndPoints() (string, string, error) {
    date := time.Now()

    dayOfWeek := date.Weekday()
    //fmt.Println("Сейчас: ", date)
    if dayOfWeek == 0 || dayOfWeek == 6 {
        monday := time.Now().AddDate(0, 0, 0-int(time.Now().Weekday())+int(time.Monday))
        sunday := time.Now().AddDate(0, 0, 13-int(time.Now().Weekday())+int(time.Monday))
        return monday.Format("2006-01-02 15:04:05"), sunday.Format("2006-01-02 15:04:05"), nil
    } else {
        monday := date.AddDate(0, 0, -int(date.Weekday())+int(time.Monday))
        sunday := date.AddDate(0, 0, -int(date.Weekday())+int(time.Sunday))
        return monday.Format("2006-01-02 15:04:05"), sunday.Format("2006-01-02 15:04:05"), nil
        //sunday := int(time.Now().Weekday()) + int(time.Monday)
        //sunday := time.Now().AddDate(0, 0, 6-int(time.Now().Weekday())+int(time.Monday))
        //fmt.Println(monday.Format("2006-01-02 15:04:05"))
    }

}

func getHomework(begin, end string) string {
    message := "Вот ваше домашнее задание: \n _________________ \n"
    db, err := sql.Open("mysql", "root:123321@/botdz")

    if err != nil {
        panic(err)
    }
    defer db.Close()
    rows, err := db.Query("select * from homework WHERE todate BETWEEN '" + begin + "' AND '" + end + "' ORDER BY todate")
    if err != nil {
        panic(err)
    }
    defer rows.Close()
    homeworks := []homework{}

    for rows.Next() {
        p := homework{}
        err := rows.Scan(&p.id, &p.text, &p.todate)
        if err != nil {
            fmt.Println(err)
            continue
        }
        homeworks = append(homeworks, p)
    }
    for _, p := range homeworks {
        message += p.text + " | Дата - " + p.todate + "\n_____________________\n"
    }
    return message
}

func sendMessage(peerID, randomID int, message string) {
    /*
        data := map[string]interface{}{
            "peer_id":      strconv.Itoa(peerID),
            "random_id":    strconv.Itoa(randomID),
            "message":      message,
            "access_token": "тут тип токен",
            "v":            "5.90",
        }
    */
    client := &http.Client{}

    urlData := url.Values{}
    urlData.Set("peer_id", strconv.Itoa(peerID))
    urlData.Set("random_id", strconv.Itoa(randomID))
    urlData.Set("message", message)
    urlData.Set("access_token", "")
    urlData.Set("v", "5.90")
    req, _ := http.NewRequest("POST", "https://api.vk.com/method/messages.send", strings.NewReader(urlData.Encode()))

    req.Header.Add("Content-Type", "application/x-www-form-urlencoded")
    resp, _ := client.Do(req)
    fmt.Println(resp)
}

func sendHomework(message string) error {
    db, err := sql.Open("mysql", "root:123321@/botdz")
    if err != nil {
        panic(err)
    }
    defer db.Close()
    rows, err := db.Query("select * from recipients")
    if err != nil {
        panic(err)
    }
    defer rows.Close()
    recipients := []recipient{}

    for rows.Next() {
        p := recipient{}
        err := rows.Scan(&p.id, &p.name, &p.userID)
        if err != nil {
            fmt.Println(err)
            continue
        }
        recipients = append(recipients, p)
    }
    for _, p := range recipients {
        rand := rand.Intn(9999-1) + 1
        sendMessage(p.userID, rand, message)
        //fmt.Println(p.userID)
    }
    return nil
}