Add a set of consts that are exposed by the Bot API (#62)

* Add support for const generation

* generate new constants

* Use ParseModeNone instead of ParseModeText

gen_consts.go

@@ -0,0 +1,37 @@
+// THIS FILE IS AUTOGENERATED. DO NOT EDIT.
+// Regen by running 'go generate' in the repo root.
+
+package gotgbot
+
+// The consts listed below represent all the update types that can be requested from telegram.
+const (
+	UpdateTypeMessage            = "message"
+	UpdateTypeEditedMessage      = "edited_message"
+	UpdateTypeChannelPost        = "channel_post"
+	UpdateTypeEditedChannelPost  = "edited_channel_post"
+	UpdateTypeInlineQuery        = "inline_query"
+	UpdateTypeChosenInlineResult = "chosen_inline_result"
+	UpdateTypeCallbackQuery      = "callback_query"
+	UpdateTypeShippingQuery      = "shipping_query"
+	UpdateTypePreCheckoutQuery   = "pre_checkout_query"
+	UpdateTypePoll               = "poll"
+	UpdateTypePollAnswer         = "poll_answer"
+	UpdateTypeMyChatMember       = "my_chat_member"
+	UpdateTypeChatMember         = "chat_member"
+	UpdateTypeChatJoinRequest    = "chat_join_request"
+)
+
+// The consts listed below represent all the parse_mode options that can be sent to telegram.
+const (
+	ParseModeHTML       = "HTML"
+	ParseModeMarkdownV2 = "MarkdownV2"
+	ParseModeMarkdown   = "Markdown"
+	ParseModeNone       = ""
+)
+
+// The consts listed below represent all the sticker types that can be obtained from telegram.
+const (
+	StickerTypeRegular     = "regular"
+	StickerTypeMask        = "mask"
+	StickerTypeCustomEmoji = "custom_emoji"
+)

scripts/generate/common.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"errors"
 	"fmt"
 	"regexp"
 	"sort"
@@ -240,3 +241,29 @@ func getTypesByName(d APIDescription, typeNames []string) ([]TypeDescription, er
 
 	return types, nil
 }
+
+// extractQuotedValues is a very basic quote extraction method. It only works on normal double quotes ("), it does not
+// handle any sort of escaping, and it expects an even number of quotes to function.
+// But that's all we need for this package, and so we're happy.
+func extractQuotedValues(in string) ([]string, error) {
+	if strings.Count(in, "\"")%2 != 0 {
+		return nil, errors.New("uneven number of quotes in string")
+	}
+
+	var out []string
+	startIdx := -1
+	for idx, r := range in {
+		if r == '"' {
+			if startIdx == -1 {
+				// This is an opening quote
+				startIdx = idx
+				continue
+			}
+
+			// This is a closing quote, so append to outputs and reset startIdx.
+			out = append(out, in[startIdx+1:idx])
+			startIdx = -1
+		}
+	}
+	return out, nil
+}

scripts/generate/consts.go

@@ -0,0 +1,104 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+)
+
+func generateConsts(d APIDescription) error {
+	consts := strings.Builder{}
+	consts.WriteString(`
+// THIS FILE IS AUTOGENERATED. DO NOT EDIT.
+// Regen by running 'go generate' in the repo root.
+
+package gotgbot
+
+`)
+
+	updateConsts, err := generateUpdateTypeConsts(d)
+	if err != nil {
+		return fmt.Errorf("failed to generate consts for update types: %w", err)
+	}
+	consts.WriteString(updateConsts)
+
+	consts.WriteString(generateParseModeConsts())
+
+	stickerTypeConsts, err := generateStickerTypeConsts(d)
+	if err != nil {
+		return fmt.Errorf("failed to generate consts for sticker types: %w", err)
+	}
+	consts.WriteString(stickerTypeConsts)
+
+	return writeGenToFile(consts, "gen_consts.go")
+}
+
+func generateUpdateTypeConsts(d APIDescription) (string, error) {
+	updType, ok := d.Types["Update"]
+	if !ok {
+		return "", errors.New("missing 'Update' type data")
+	}
+	out := strings.Builder{}
+	out.WriteString("// The consts listed below represent all the update types that can be requested from telegram.\n")
+	out.WriteString("const (\n")
+	for _, f := range updType.Fields {
+		if f.Required {
+			// All the update types are optional, so skip required values.
+			continue
+		}
+		constName := "UpdateType" + snakeToTitle(f.Name)
+		out.WriteString(writeConst(constName, f.Name))
+	}
+	out.WriteString(")\n\n")
+	return out.String(), nil
+}
+
+func generateStickerTypeConsts(d APIDescription) (string, error) {
+	updType, ok := d.Types["Sticker"]
+	if !ok {
+		return "", errors.New("missing 'Sticker' type data")
+	}
+	out := strings.Builder{}
+	out.WriteString("// The consts listed below represent all the sticker types that can be obtained from telegram.\n")
+	out.WriteString("const (\n")
+	for _, f := range updType.Fields {
+		if f.Name != "type" {
+			// the field we want to look at is called "type", ignore all others.
+			continue
+		}
+		types, err := extractQuotedValues(f.Description)
+		if err != nil {
+			return "", fmt.Errorf("failed to get quoted types: %w", err)
+		}
+		for _, t := range types {
+			constName := "StickerType" + snakeToTitle(t)
+			out.WriteString(writeConst(constName, t))
+		}
+	}
+	out.WriteString(")\n\n")
+	return out.String(), nil
+}
+
+func generateParseModeConsts() string {
+	// Adding these manually because they're not part of the spec, and theyre not going to change much anyway.
+	formattingTypes := []string{"HTML", "MarkdownV2", "Markdown", "None"}
+
+	out := strings.Builder{}
+	out.WriteString("// The consts listed below represent all the parse_mode options that can be sent to telegram.\n")
+	out.WriteString("const (\n")
+	for _, t := range formattingTypes {
+		constName := "ParseMode" + t
+		if t == "None" {
+			// no parsemode == empty string value.
+			out.WriteString(writeConst(constName, ""))
+			continue
+		}
+		out.WriteString(writeConst(constName, t))
+	}
+	out.WriteString(")\n\n")
+	return out.String()
+}
+
+func writeConst(name string, value string) string {
+	return fmt.Sprintf("%s = \"%s\"\n", name, value)
+}

scripts/generate/gen.go

@@ -181,6 +181,10 @@ func generate(d APIDescription) error {
 		return fmt.Errorf("failed to generate helpers: %w", err)
 	}
 
+	if err := generateConsts(d); err != nil {
+		return fmt.Errorf("failed to generate consts: %w", err)
+	}
+
 	return nil
 }
 

scripts/generate/helpers.go

@@ -21,7 +21,7 @@ package gotgbot
 
 		helper, err := generateHelperDef(d, tgMethod)
 		if err != nil {
-			return fmt.Errorf("failed to generate helpersfor %s: %w", tgMethodName, err)
+			return fmt.Errorf("failed to generate helpers for %s: %w", tgMethodName, err)
 		}
 
 		if helper == "" {