Add mol command and pubchem searching

commands/mol.go

@@ -0,0 +1,62 @@
+package commands
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"regexp"
+	"strings"
+
+	tgbotapi "github.com/go-telegram-bot-api/telegram-bot-api/v5"
+)
+
+type MolCommand struct{}
+
+func (m MolCommand) Name() string {
+	return "mol"
+}
+
+func (m MolCommand) Help() string {
+	return "2D molecular structure. Example usage: /mol tetraethylgermane"
+}
+
+func (m MolCommand) Execute(update tgbotapi.Update, bot *tgbotapi.BotAPI) {
+	args := strings.TrimSpace(update.Message.CommandArguments())
+	if args == "" {
+		msg := tgbotapi.NewMessage(update.Message.Chat.ID, "Input a molecule name dumbass")
+		bot.Send(msg)
+		return
+	}
+	cid, err := fetchPubchemCID(args)
+	if err != nil {
+		msg := tgbotapi.NewMessage(update.Message.Chat.ID, "Structure not found")
+		bot.Send(msg)
+		return
+	}
+	imgURL := fmt.Sprintf("https://pubchem.ncbi.nlm.nih.gov/image/imgsrv.fcgi?t=l&cid=%s", cid)
+	msg := tgbotapi.NewMessage(update.Message.Chat.ID, imgURL)
+	bot.Send(msg)
+}
+
+func fetchPubchemCID(compound string) (string, error) {
+	url := "https://pubchem.ncbi.nlm.nih.gov/compound/" + compound
+	resp, err := http.Get(url)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", err
+	}
+	re := regexp.MustCompile(`<meta name="pubchem_uid_value" content="(\d+)"/?>`)
+	matches := re.FindStringSubmatch(string(body))
+	if len(matches) < 2 {
+		return "", fmt.Errorf("CID not found")
+	}
+	return matches[1], nil
+}
+
+func init() {
+	Register(MolCommand{})
+}