send responses based on Accept header, add pages for error cases

src/main/java/me/youhavetrouble/inviter/http/endpoints/GetDiscordInviteByGuildId.java

@@ -8,12 +8,34 @@ import me.youhavetrouble.inviter.discord.GuildSettings;
 import org.jetbrains.annotations.NotNull;
 
 import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
 import java.util.regex.Pattern;
 
 public class GetDiscordInviteByGuildId implements EndpointHandler {
 
     private final Pattern pathPattern = Pattern.compile("^/invite/\\d{10,18}$");
 
+    private final String invitesDisabledTemplate, botNotInGuildTemplate;
+
+    public GetDiscordInviteByGuildId() {
+        String invitesDisabledTemplate = null;
+        try (InputStream resource = this.getClass().getResourceAsStream("/template/invites-paused.html")) {
+            invitesDisabledTemplate = new String(resource.readAllBytes());
+        } catch (IOException | NullPointerException e) {
+            Main.LOGGER.warn("Failed to load template for invites disabled page", e);
+        }
+        this.invitesDisabledTemplate = invitesDisabledTemplate;
+
+        String botNotInGuildTemplate = null;
+        try (InputStream resource = this.getClass().getResourceAsStream("/template/guild-not-supported.html")) {
+            botNotInGuildTemplate = new String(resource.readAllBytes());
+        } catch (IOException | NullPointerException e) {
+            Main.LOGGER.warn("Failed to load template for guild not supported page", e);
+        }
+        this.botNotInGuildTemplate = botNotInGuildTemplate;
+    }
+
     @NotNull
     @Override
     public Pattern pathPattern() {
@@ -39,17 +61,18 @@ public class GetDiscordInviteByGuildId implements EndpointHandler {
             return;
         }
 
-        DiscordInviteManager inviteManager = Main.getDiscordInviteMenager();
         GuildSettings settings = Main.getStorage().getGuildSettings(guildIdLong);
-        DiscordInvite invite = inviteManager.getInvite(guildIdLong);
 
-        if (invite == null) {
+        if (!settings.invitesEnabled()) {
-            exchange.sendResponseHeaders(404, -1); // Not Found
+            sendInvitesPausedTemplate(exchange);
             return;
         }
 
-        if (!settings.invitesEnabled()) {
+        DiscordInviteManager inviteManager = Main.getDiscordInviteMenager();
-            exchange.sendResponseHeaders(401, -1); // Not Found
+        DiscordInvite invite = inviteManager.getInvite(guildIdLong);
+
+        if (invite == null) {
+            sendBotNotInGuildTemplate(exchange);
             return;
         }
 
@@ -72,10 +95,62 @@ public class GetDiscordInviteByGuildId implements EndpointHandler {
                 exchange.sendResponseHeaders(307, -1);
             }
         }
-
-
-
     }
 
 
+    private void sendInvitesPausedTemplate(HttpExchange exchange) throws IOException {
+        String message = "Guild you were invited to currently has invites disabled. Try again later.";
+        switch (exchange.getRequestHeaders().getFirst("Accept")) {
+            case "text/plain" -> {
+                exchange.getResponseHeaders().set("Content-Type", "text/plain; charset=UTF-8");
+
+                exchange.sendResponseHeaders(401, message.getBytes(StandardCharsets.UTF_8).length);
+                exchange.getResponseBody().write(message.getBytes(StandardCharsets.UTF_8));
+            }
+            case "application/json" -> {
+                exchange.getResponseHeaders().set("Content-Type", "application/json; charset=UTF-8");
+                String jsonResponse = "{\"error\": \"%s\"}".formatted(message);
+                exchange.sendResponseHeaders(401, jsonResponse.length());
+                exchange.getResponseBody().write(jsonResponse.getBytes(StandardCharsets.UTF_8));
+            }
+            default -> {
+                if (invitesDisabledTemplate != null) {
+                    exchange.getResponseHeaders().set("Content-Type", "text/html; charset=UTF-8");
+                    exchange.sendResponseHeaders(401, invitesDisabledTemplate.getBytes(StandardCharsets.UTF_8).length);
+                    exchange.getResponseBody().write(invitesDisabledTemplate.getBytes(StandardCharsets.UTF_8));
+                    exchange.getResponseBody().close();
+                } else {
+                    exchange.sendResponseHeaders(401, -1);
+                }
+            }
+        }
+    }
+
+    private void sendBotNotInGuildTemplate(HttpExchange exchange) throws IOException {
+        String message = "Guild you were invited to is not supported by the bot. Try again later.";
+        switch (exchange.getRequestHeaders().getFirst("Accept")) {
+            case "text/plain" -> {
+                exchange.getResponseHeaders().set("Content-Type", "text/plain; charset=UTF-8");
+                exchange.sendResponseHeaders(404, message.getBytes(StandardCharsets.UTF_8).length);
+                exchange.getResponseBody().write(message.getBytes(StandardCharsets.UTF_8));
+            }
+            case "application/json" -> {
+                exchange.getResponseHeaders().set("Content-Type", "application/json; charset=UTF-8");
+                String jsonResponse = "{\"error\": \"%s\"}".formatted(message);
+                exchange.sendResponseHeaders(404, jsonResponse.length());
+                exchange.getResponseBody().write(jsonResponse.getBytes(StandardCharsets.UTF_8));
+            }
+            default -> {
+                if (botNotInGuildTemplate != null) {
+                    exchange.getResponseHeaders().set("Content-Type", "text/html; charset=UTF-8");
+                    exchange.sendResponseHeaders(404, botNotInGuildTemplate.getBytes(StandardCharsets.UTF_8).length);
+                    exchange.getResponseBody().write(botNotInGuildTemplate.getBytes(StandardCharsets.UTF_8));
+                    exchange.getResponseBody().close();
+                } else {
+                    exchange.sendResponseHeaders(404, -1);
+                }
+            }
+        }
+    }
+
 }

src/main/resources/template/guild-not-supported.html

@@ -0,0 +1,107 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <meta name="title" content="Discord Inviter">
+    <meta name="description" content="A simple tool to invite users to a Discord server"/>
+    <meta name="keywords" content="Discord, Inviter, Tool, Invite Users"/>
+    <meta name="author" content="YouHaveTrouble"/>
+    <meta name="og:type" content="website"/>
+    <meta name="og:title" content="Discord Inviter"/>
+    <meta name="og:description" content="A simple tool to invite users to a Discord server"/>
+    <meta name="og:url" content="https://inviter.yht.one"/>
+    <meta name="twitter:title" content="Discord Inviter"/>
+    <meta name="twitter:description" content="A simple tool to invite users to a Discord server"/>
+    <title>Discord Inviter</title>
+    <style>
+        :root {
+            --color-primary: #5865F2;
+            --color-primary-highlight: #4752C4;
+            --color-text: #f0f0f0;
+        }
+
+        * {
+            box-sizing: border-box;
+            margin: 0;
+            padding: 0;
+            font-family: system-ui, sans-serif;
+            font-weight: normal;
+            vertical-align: baseline;
+            overflow-wrap: break-word;
+            -webkit-font-smoothing: antialiased;
+        }
+
+        body {
+            line-height: 1.5;
+            background-color: #272727;
+            color: var(--color-text);
+        }
+
+        main {
+            min-height: 100vh;
+            padding: 1rem;
+            gap: 2rem;
+            text-align: center;
+            display: flex;
+            flex-direction: column;
+            justify-content: center;
+            align-items: center;
+        }
+
+        ol, ul {
+            text-align: left;
+            margin-left: 2rem;
+        }
+
+        .highlight {
+            display: inline-block;
+            padding: 0.1rem 0.2rem;
+            background-color: rgba(255, 255, 255, 0.05);
+            border-radius: 0.2rem;
+            white-space: break-spaces;
+            overflow-wrap: anywhere;
+        }
+
+        a[href]:not([role="button"]) {
+            color: var(--color-primary);
+            text-decoration: none;
+            transition: color 0.2s ease;
+        }
+
+        a[href]:not([role="button"]):hover {
+            color: var(--color-primary-highlight);
+        }
+
+        [role="button"] {
+            display: inline-block;
+            padding: 0.5rem 1rem;
+            margin-top: 1rem;
+            background-color: var(--color-primary);
+            color: var(--color-text);
+            text-decoration: none;
+            border-radius: 0.25rem;
+            transition: background-color 0.2s ease;
+            border: none;
+            cursor: pointer;
+            font-size: 1rem;
+        }
+
+        [role="button"]:hover {
+            background-color: var(--color-primary-highlight);
+        }
+    </style>
+</head>
+<body>
+<main>
+    <form method="get">
+        <h1>Inviter</h1>
+        <p>Inviter bot is not present in the guild you're trying to join.</p>
+        <button
+                type="submit"
+                role="button"
+        >Try again</button>
+    </form>
+</main>
+</body>
+</html>

src/main/resources/template/index.html

@@ -82,6 +82,9 @@
             text-decoration: none;
             border-radius: 0.25rem;
             transition: background-color 0.2s ease;
+            border: none;
+            cursor: pointer;
+            font-size: 1rem;
         }
 
         [role="button"]:hover {

src/main/resources/template/invites-paused.html

@@ -0,0 +1,107 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <meta name="title" content="Discord Inviter">
+    <meta name="description" content="A simple tool to invite users to a Discord server"/>
+    <meta name="keywords" content="Discord, Inviter, Tool, Invite Users"/>
+    <meta name="author" content="YouHaveTrouble"/>
+    <meta name="og:type" content="website"/>
+    <meta name="og:title" content="Discord Inviter"/>
+    <meta name="og:description" content="A simple tool to invite users to a Discord server"/>
+    <meta name="og:url" content="https://inviter.yht.one"/>
+    <meta name="twitter:title" content="Discord Inviter"/>
+    <meta name="twitter:description" content="A simple tool to invite users to a Discord server"/>
+    <title>Discord Inviter</title>
+    <style>
+        :root {
+            --color-primary: #5865F2;
+            --color-primary-highlight: #4752C4;
+            --color-text: #f0f0f0;
+        }
+
+        * {
+            box-sizing: border-box;
+            margin: 0;
+            padding: 0;
+            font-family: system-ui, sans-serif;
+            font-weight: normal;
+            vertical-align: baseline;
+            overflow-wrap: break-word;
+            -webkit-font-smoothing: antialiased;
+        }
+
+        body {
+            line-height: 1.5;
+            background-color: #272727;
+            color: var(--color-text);
+        }
+
+        main {
+            min-height: 100vh;
+            padding: 1rem;
+            gap: 2rem;
+            text-align: center;
+            display: flex;
+            flex-direction: column;
+            justify-content: center;
+            align-items: center;
+        }
+
+        ol, ul {
+            text-align: left;
+            margin-left: 2rem;
+        }
+
+        .highlight {
+            display: inline-block;
+            padding: 0.1rem 0.2rem;
+            background-color: rgba(255, 255, 255, 0.05);
+            border-radius: 0.2rem;
+            white-space: break-spaces;
+            overflow-wrap: anywhere;
+        }
+
+        a[href]:not([role="button"]) {
+            color: var(--color-primary);
+            text-decoration: none;
+            transition: color 0.2s ease;
+        }
+
+        a[href]:not([role="button"]):hover {
+            color: var(--color-primary-highlight);
+        }
+
+        [role="button"] {
+            display: inline-block;
+            padding: 0.5rem 1rem;
+            margin-top: 1rem;
+            background-color: var(--color-primary);
+            color: var(--color-text);
+            text-decoration: none;
+            border-radius: 0.25rem;
+            transition: background-color 0.2s ease;
+            border: none;
+            cursor: pointer;
+            font-size: 1rem;
+        }
+
+        [role="button"]:hover {
+            background-color: var(--color-primary-highlight);
+        }
+    </style>
+</head>
+<body>
+<main>
+    <form method="get">
+        <h1>Inviter</h1>
+        <p>Guild you were invited to currently has invites disabled. Try again later.</p>
+        <button
+                type="submit"
+                role="button"
+        >Try again</button>
+    </form>
+</main>
+</body>
+</html>