morse command

include/hammy/job.h

@@ -55,11 +55,16 @@ int64_t hammy_job_age_ms(const hammy_job_t* job, struct discord* client);
 // Does not destroy the job.
 void hammy_job_run(hammy_job_t* job, struct discord* client, hammy_refdb_t* refdb);
  
-// Edits the (already deferred) interaction response with a plain text body.
+// Edits the (already deferred) interaction response with a titled embed,
+// falling back to a plain text body only if the embed cannot be built.
 // Used by hammy_job_run() and by the pool's error paths.
+//
+// Only valid on the deferred path: it edits a response, so something must have
+// answered the interaction already. Instant handlers want hammy_job_respond().
 void hammy_job_reply(const hammy_job_t* job, struct discord* client, const char* title, const char* content, bool isError);
 
-// Sends a fresh interaction response with a plain text body.
+// Sends a fresh interaction response with a titled embed, falling back to a
+// plain text body only if the embed cannot be built.
 // Only valid on the instant path, where nothing has been sent yet.
 void hammy_job_respond(const hammy_job_t* job, struct discord* client, const char* title, const char* content, bool isError);
 

include/hammy/refdb.h

@@ -15,11 +15,15 @@
 
 #define HAMMY_CALLSIGN_MAX 32
 #define HAMMY_ENTITY_NAME_MAX 64
+// Longest code in the morse table is '$' ('...-..-'), seven characters.
+#define HAMMY_MORSE_MAX 16
 
 struct hammy_refdb_t {
     sqlite3* handle;
     sqlite3_stmt* stExact;
     sqlite3_stmt* stPrefix;
+    sqlite3_stmt* stMorse;
+    char morseCode[HAMMY_MORSE_MAX]; // Scratch for the last hammy_refdb_get_morse() hit
     char version[64];
 };
 
@@ -53,6 +57,13 @@ bool hammy_refdb_close(hammy_refdb_t** db);
 // Returns false if nothing matched.
 bool hammy_refdb_dxcc(hammy_refdb_t* db, const char* callsign, hammy_dxcc_t* out);
 
+// Looks up a character in the Morse table. Case-insensitive; non-ASCII bytes
+// never match. Returns false if not found, leaving *out untouched.
+//
+// On a hit *out points at storage owned by the refdb and is only valid until
+// the NEXT call on the same handle - copy it if it has to outlive that.
+bool hammy_refdb_get_morse(hammy_refdb_t* db, char c, const char** out);
+ 
 // Bundle version string from ref_meta, or NULL. Owned by the refdb.
 const char* hammy_refdb_version(hammy_refdb_t* db);
 

src/commands/morse.c

@@ -0,0 +1,143 @@
+#include <concord/discord.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <hammy/command.h>
+#include <hammy/job.h>
+#include <hammy/refdb.h>
+
+#include <dlibc/vector.h>
+
+// The reply goes out as an embed description, which Discord caps at 4096
+// characters, so the two halves get separate budgets that still leave room for
+// the labels between them. Capping at all is what keeps an unbounded,
+// user-controlled VLA off the stack: a command option runs to 6000 characters,
+// and every one of them can expand to eight.
+#define HAMMY_MORSE_ECHO_MAX 512
+#define HAMMY_MORSE_CODE_MAX 3072
+#define HAMMY_MORSE_TRUNCATED " ... (truncated)"
+
+// Appends one token, space-separated from whatever is already in the buffer and
+// optionally preceded by a word-gap slash. All or nothing: returns false and
+// leaves the buffer untouched when the whole thing would not fit, so the caller
+// can stop without a half-written character on the end.
+//
+// len counts bytes excluding the terminator, and the buffer stays terminated
+// throughout - which is what the strcat-onto-uninitialised-stack version this
+// replaces got wrong: strcat needs a terminated destination to start from, and
+// an uninitialised one made the reply random bytes that Discord rejected as
+// invalid JSON.
+static bool morse_append(char* buf, size_t cap, size_t* len, bool gap, const char* token) {
+    size_t n = strlen(token);
+    size_t need = (*len > 0 ? 1 : 0) + (gap ? 2 : 0) + n;
+
+    if (*len + need + 1 > cap) { return false; }
+
+    if (*len > 0) { buf[(*len)++] = ' '; }
+
+    if (gap) {
+        buf[(*len)++] = '/';
+        buf[(*len)++] = ' ';
+    }
+
+    memcpy(buf + *len, token, n);
+    *len += n;
+    buf[*len] = '\0';
+
+    return true;
+}
+
+static bool morse_is_gap(char c) {
+    return c == ' ' || c == '\t' || c == '\n' || c == '\r';
+}
+
+// How many bytes of s can be kept without exceeding max OR splitting a UTF-8
+// sequence. Half a sequence would make the JSON body invalid and cost the whole
+// reply, so the cut walks back to the nearest lead byte.
+//
+// Only the echoed input needs this - the generated code is all ASCII.
+static size_t morse_utf8_trim(const char* s, size_t max) {
+    size_t n = strlen(s);
+    if (n <= max) { return n; }
+
+    // Continuation bytes are 10xxxxxx. Dropping back past them lands either on
+    // ASCII or on the lead byte of the sequence being cut, and that lead byte
+    // is then excluded too, since the kept range is [0, n).
+    n = max;
+    while (n > 0 && ((unsigned char)s[n] & 0xC0) == 0x80) { n--; }
+
+    return n;
+}
+
+// Instant command: runs on the gateway thread, sends a fresh response.
+void hammy_cmd_morse(const hammy_job_t* job, struct discord* client, const hammy_refdb_t* refdb) {
+    // Get the text argument from the job
+    const char* text = hammy_job_get_arg(job, "text");
+    if (!text) {
+        hammy_job_respond(job, client, "Error", "No text provided for Morse code conversion.", true);
+        return;
+    }
+
+    // Echoed back trimmed rather than whole: sizing a buffer from the option
+    // would put an unbounded, user-controlled allocation on the stack.
+    char echo[HAMMY_MORSE_ECHO_MAX + sizeof(HAMMY_MORSE_TRUNCATED)];
+    size_t echoLen = morse_utf8_trim(text, HAMMY_MORSE_ECHO_MAX);
+
+    memcpy(echo, text, echoLen);
+    echo[echoLen] = '\0';
+
+    if (text[echoLen] != '\0') {
+        memcpy(echo + echoLen, HAMMY_MORSE_TRUNCATED, sizeof(HAMMY_MORSE_TRUNCATED));
+    }
+
+    char morse[HAMMY_MORSE_CODE_MAX + sizeof(HAMMY_MORSE_TRUNCATED)];
+    morse[0] = '\0';
+
+    // Room held back so the truncation note always fits.
+    const size_t cap = sizeof(morse) - (sizeof(HAMMY_MORSE_TRUNCATED) - 1);
+
+    size_t len = 0;
+    bool pendingGap = false;
+    bool truncated = false;
+
+    for (const char* p = text; *p; p++) {
+        // The morse table has no row for whitespace, and rendering it as an
+        // unknown character would lose the word boundaries. Held rather than
+        // emitted on the spot so leading, trailing and repeated spaces do not
+        // stack up slashes.
+        if (morse_is_gap(*p)) {
+            pendingGap = (len > 0);
+            continue;
+        }
+
+        const char* code = NULL;
+        if (!hammy_refdb_get_morse(refdb, *p, &code)) {
+            code = "?"; // Handle unknown characters
+        }
+
+        if (!morse_append(morse, cap, &len, pendingGap, code)) {
+            truncated = true;
+            break;
+        }
+
+        pendingGap = false;
+    }
+
+    // All whitespace, or an empty string: Discord refuses an empty body, so
+    // there is nothing to send back.
+    if (len == 0) {
+        hammy_job_respond(job, client, "Error", "Nothing to convert.", true);
+        return;
+    }
+
+    if (truncated) {
+        memcpy(morse + len, HAMMY_MORSE_TRUNCATED, sizeof(HAMMY_MORSE_TRUNCATED));
+    }
+
+    // Reply with the converted Morse code, alongside the text it came from.
+    char body[sizeof(echo) + sizeof(morse) + 32];
+    snprintf(body, sizeof(body), "Original text: `%s`\nMorse: `%s`", echo, morse);
+
+    hammy_job_respond(job, client, "Morse Code Conversion", body, false);
+}

src/hammy/command.c

@@ -7,6 +7,18 @@
 // so adding a command touches exactly two places: its own .c file and this
 // table.
 void hammy_cmd_ping(const hammy_job_t* job, struct discord* client, const hammy_refdb_t* refdb);
+void hammy_cmd_morse(const hammy_job_t* job, struct discord* client, const hammy_refdb_t* refdb);
+
+// TODO: Temporary - move to a proper options system; e.g. a vector of heap-allocated options or something. For now, just point at static storage.
+static struct discord_application_command_option morse_opts[] = {
+    { .type = DISCORD_APPLICATION_OPTION_STRING, .name = "text",
+      .description = "Text to convert to Morse code", .required = true },
+};
+
+static struct discord_application_command_options morse_opts_struct = {
+    .size = 1,
+    .array = morse_opts
+};
 
 // The command table. Pure data - no allocation, no lifetime, no destructor.
 // Copying an entry into the bot's vector is a plain struct copy, and the vector
@@ -14,8 +26,8 @@ void hammy_cmd_ping(const hammy_job_t* job, struct discord* client, const hammy_
 //
 // Field order: name, description, options, handler, instant.
 static const hammy_command_t hammy_builtin_commands[] = {
-    { "ping", "Check whether Hammy is alive and how fast it is responding",
-      NULL, &hammy_cmd_ping, true },
+    { "ping", "Check whether Hammy is alive and how fast it is responding", NULL, &hammy_cmd_ping, true },
+    { "morse", "Text to and from Morse code", &morse_opts_struct, &hammy_cmd_morse, true },
 
     // Tier 0 commands go here as they land. All pure computation, so instant:
     //   { "grid",  "Maidenhead locator conversions", &grid_opts,  &hammy_cmd_grid,  true },

src/hammy/job.c

@@ -22,6 +22,17 @@ static char* hammy_strdup(const char* src) {
     return dst;
 }
 
+// Logs a failed send, and only a failed send. Concord returns CCORD_PENDING for
+// an asynchronous request (which is every request made with a NULL ret, i.e.
+// all of ours) - the request has been queued, not rejected, so treating it as
+// an error warned on every single reply that actually worked.
+static void hammy_job_check_send(const hammy_job_t* job, CCORDcode code) {
+    if (code == CCORD_OK || code == CCORD_PENDING) { return; }
+
+    log_warn("[job] Failed to send interaction response for interaction %" PRIu64 ": %s (%d)",
+             job->id, ccord_strerror(code), code);
+}
+
 // Pulls the invoking user out of the event. Guild interactions carry it under
 // member->user, DM interactions under user directly.
 static u64snowflake hammy_job_extract_user(const struct discord_interaction* event) {
@@ -129,31 +140,26 @@ int64_t hammy_job_age_ms(const hammy_job_t* job, struct discord* client) {
 void hammy_job_reply(const hammy_job_t* job, struct discord* client, const char* title, const char* content, bool isError) {
     if (!job || !client || !content || !title) { return; }
 
-    if (hammy_embeds_customembed(client, NULL, NULL, title, content, NULL, 0, isError ? 0xFF0000 : 0x00FF00)) {
-        struct discord_interaction_response params = {
-            .type = DISCORD_INTERACTION_CHANNEL_MESSAGE_WITH_SOURCE,
-            .data = &(struct discord_interaction_callback_data){
-                .content = (char*)content
-            }
-        };
+    // Editing, not creating: every caller is on the deferred path, where the
+    // gateway thread already sent DEFERRED_CHANNEL_MESSAGE_WITH_SOURCE. A second
+    // create on the same interaction is refused with "Interaction has already
+    // been acknowledged" (40060). Instant handlers want hammy_job_respond().
+    struct discord_edit_original_interaction_response params = { 0 };
 
-        CCORDcode code = discord_create_interaction_response(client, job->id, job->token, &params, NULL);
-        if (code != CCORD_OK) {
-            log_warn("[job] Failed to send interaction response for interaction %" PRIu64 ": %d", job->id, code);
-        }
+    // Both must outlive the call, so neither can be a compound literal inside
+    // the branch below.
+    struct discord_embed embed[1];
+    struct discord_embeds embeds = { .size = 1, .array = embed };
+
+    if (hammy_embeds_customembed(client, embed, NULL, title, content, NULL, 0, isError ? 0xFF0000 : 0x00FF00)) {
+        params.embeds = &embeds;
     } else {
-        struct discord_interaction_response params = {
-            .type = DISCORD_INTERACTION_CHANNEL_MESSAGE_WITH_SOURCE,
-            .data = &(struct discord_interaction_callback_data){
-                .content = (char*)content
+        // Only reachable on a bad argument, but a plain-text body still beats
+        // sending nothing at all.
+        params.content = (char*)content;
     }
-        };
 
-        CCORDcode code = discord_create_interaction_response(client, job->id, job->token, &params, NULL);
-        if (code != CCORD_OK) {
-            log_warn("[job] Failed to send interaction response for interaction %" PRIu64 ": %d", job->id, code);
-        }
-    }
+    hammy_job_check_send(job, discord_edit_original_interaction_response(client, job->appId, job->token, &params, NULL));
 }
 
 void hammy_job_respond(const hammy_job_t* job, struct discord* client, const char* title, const char* content, bool isError) {
@@ -171,10 +177,7 @@ void hammy_job_respond(const hammy_job_t* job, struct discord* client, const cha
             }
         };
 
-        CCORDcode code = discord_create_interaction_response(client, job->id, job->token, &params, NULL);
-        if (code != CCORD_OK) {
-            log_warn("[job] Failed to send interaction response for interaction %" PRIu64 ": %d", job->id, code);
-        }
+        hammy_job_check_send(job, discord_create_interaction_response(client, job->id, job->token, &params, NULL));
     } else {
         struct discord_interaction_response params = {
             .type = DISCORD_INTERACTION_CHANNEL_MESSAGE_WITH_SOURCE,
@@ -183,10 +186,7 @@ void hammy_job_respond(const hammy_job_t* job, struct discord* client, const cha
             }
         };
 
-        CCORDcode code = discord_create_interaction_response(client, job->id, job->token, &params, NULL);
-        if (code != CCORD_OK) {
-            log_warn("[job] Failed to send interaction response for interaction %" PRIu64 ": %d", job->id, code);
-        }
+        hammy_job_check_send(job, discord_create_interaction_response(client, job->id, job->token, &params, NULL));
     }
 }
 

src/hammy/refdb.c

@@ -25,6 +25,9 @@ static const char* SQL_PREFIX =
 static const char* SQL_VERSION =
     "SELECT value FROM ref_meta WHERE key = 'bundle_version'";
 
+static const char* SQL_MORSE =
+    "SELECT code FROM morse WHERE character = UPPER(?1) LIMIT 1";
+
 // Authorizer: the connection may read, and nothing else.
 //
 // SQLITE_OPEN_READONLY protects the MAIN database file. It does not stop
@@ -100,6 +103,7 @@ hammy_refdb_t* hammy_refdb_open(const char* path) {
 
     if (!prepare(db->handle, SQL_EXACT, &db->stExact)) { goto fail; }
     if (!prepare(db->handle, SQL_PREFIX, &db->stPrefix)) { goto fail; }
+    if (!prepare(db->handle, SQL_MORSE, &db->stMorse)) { goto fail; }
 
     sqlite3_stmt* st = NULL;
     if (prepare(db->handle, SQL_VERSION, &st)) {
@@ -129,6 +133,7 @@ bool hammy_refdb_close(hammy_refdb_t** db) {
     // (sqlite3_close() returns SQLITE_BUSY and the handle leaks)
     if (d->stExact) { sqlite3_finalize(d->stExact); }
     if (d->stPrefix) { sqlite3_finalize(d->stPrefix); }
+    if (d->stMorse) { sqlite3_finalize(d->stMorse); }
     
     if (d->handle) { sqlite3_close(d->handle); }
 
@@ -260,3 +265,38 @@ bool hammy_refdb_dxcc(hammy_refdb_t* db, const char* callsign, hammy_dxcc_t* out
     return search_prefixes(db, call, out);
 }
 
+bool hammy_refdb_get_morse(hammy_refdb_t* db, char c, const char** out) {
+    if (!db || !out) { return false; }
+
+    // The table is ASCII (ITU-R M.1677-1 has no non-Latin extensions), and a
+    // single byte out of a multi-byte UTF-8 sequence is not valid text to bind,
+    // so anything with the high bit set is a miss without touching SQLite.
+    if ((unsigned char)c & 0x80u) { return false; }
+
+    // Run the query with the character as a string. SQLite's UPPER() handles case-insensitivity.
+    // SQLITE_STATIC is safe because the statement is reset before this returns,
+    // so key never outlives the binding that points at it.
+    char key[2] = { c, '\0' };
+
+    sqlite3_reset(db->stMorse);
+    sqlite3_clear_bindings(db->stMorse);
+    sqlite3_bind_text(db->stMorse, 1, key, 1, SQLITE_STATIC);
+
+    bool hit = false;
+
+    if (sqlite3_step(db->stMorse) == SQLITE_ROW) {
+        const unsigned char* code = sqlite3_column_text(db->stMorse, 0);
+
+        if (code) {
+            // Copied rather than handed back directly: the column pointer dies
+            // at the reset below, and the caller has no way to know that.
+            snprintf(db->morseCode, sizeof(db->morseCode), "%s", (const char*)code);
+            *out = db->morseCode;
+            hit = true;
+        }
+    }
+
+    sqlite3_reset(db->stMorse);
+
+    return hit;
+}