command: split big command handler switch into separate functions

This gets rid of run_command() and its big switch statement, which was
an idiotically big function of almost 1000 lines.

The switch is replaced with a callback per command, and each command is
now implemented in its own function. Command IDs are not needed anymore,
so the mp_command_type enum disappears.

There should be no functional changes, but since this refactors 64
commands, regressions are possible.

The handler() parameter is void*, because in theory the input code is
supposed to be independent of the player core code. For example, you
should be able to reuse the command parser code for some other part of
mpv. In practice, the variable containing command list is defined in the
player core anyway, so you could say this doesn't work. But I'm still
trying to hold onto this idea, so I went with void*.

input/cmd_list.h

@@ -25,10 +25,13 @@
 
 #define MP_CMD_OPT_ARG 0x1000
 
+struct mp_cmd_ctx;
+
 struct mp_cmd_def {
-    int id;             // one of MP_CMD_...
     const char *name;   // user-visible name (as used in input.conf)
+    void (*handler)(void *ctx);
     const struct m_option args[MP_CMD_DEF_MAX_ARGS];
+    const void *priv;   // for free use by handler()
     bool allow_auto_repeat; // react to repeated key events
     bool on_updown;     // always emit it on both up and down key events
     bool vararg;        // last argument can be given 0 to multiple times
@@ -40,93 +43,6 @@ struct mp_cmd_def {
 
 extern const struct mp_cmd_def mp_cmds[];
 
-// All command IDs
-enum mp_command_type {
-    MP_CMD_IGNORE,
-    MP_CMD_SEEK,
-    MP_CMD_REVERT_SEEK,
-    MP_CMD_QUIT,
-    MP_CMD_QUIT_WATCH_LATER,
-    MP_CMD_PLAYLIST_NEXT,
-    MP_CMD_PLAYLIST_PREV,
-    MP_CMD_SCREENSHOT,
-    MP_CMD_SCREENSHOT_TO_FILE,
-    MP_CMD_SCREENSHOT_RAW,
-    MP_CMD_LOADFILE,
-    MP_CMD_LOADLIST,
-    MP_CMD_PLAYLIST_CLEAR,
-    MP_CMD_PLAYLIST_REMOVE,
-    MP_CMD_PLAYLIST_MOVE,
-    MP_CMD_PLAYLIST_SHUFFLE,
-    MP_CMD_SUB_STEP,
-    MP_CMD_SUB_SEEK,
-    MP_CMD_TV_LAST_CHANNEL,
-    MP_CMD_FRAME_STEP,
-    MP_CMD_FRAME_BACK_STEP,
-    MP_CMD_RUN,
-    MP_CMD_SUB_ADD,
-    MP_CMD_SUB_REMOVE,
-    MP_CMD_SUB_RELOAD,
-    MP_CMD_SET,
-    MP_CMD_CHANGE_LIST,
-    MP_CMD_PRINT_TEXT,
-    MP_CMD_SHOW_TEXT,
-    MP_CMD_EXPAND_TEXT,
-    MP_CMD_SHOW_PROGRESS,
-    MP_CMD_ADD,
-    MP_CMD_CYCLE,
-    MP_CMD_MULTIPLY,
-    MP_CMD_CYCLE_VALUES,
-    MP_CMD_STOP,
-    MP_CMD_AUDIO_ADD,
-    MP_CMD_AUDIO_REMOVE,
-    MP_CMD_AUDIO_RELOAD,
-
-    MP_CMD_ENABLE_INPUT_SECTION,
-    MP_CMD_DISABLE_INPUT_SECTION,
-    MP_CMD_DEFINE_INPUT_SECTION,
-
-    MP_CMD_AB_LOOP,
-
-    MP_CMD_DROP_BUFFERS,
-
-    MP_CMD_MOUSE,
-    MP_CMD_KEYPRESS,
-    MP_CMD_KEYDOWN,
-    MP_CMD_KEYUP,
-
-    /// Audio Filter commands
-    MP_CMD_AF,
-    MP_CMD_AF_COMMAND,
-    MP_CMD_AO_RELOAD,
-
-    /// Video filter commands
-    MP_CMD_VF,
-    MP_CMD_VF_COMMAND,
-
-    /// Internal for Lua scripts
-    MP_CMD_SCRIPT_BINDING,
-    MP_CMD_SCRIPT_MESSAGE,
-    MP_CMD_SCRIPT_MESSAGE_TO,
-
-    MP_CMD_OVERLAY_ADD,
-    MP_CMD_OVERLAY_REMOVE,
-
-    MP_CMD_WRITE_WATCH_LATER_CONFIG,
-
-    MP_CMD_HOOK_ADD,
-    MP_CMD_HOOK_ACK,
-
-    MP_CMD_RESCAN_EXTERNAL_FILES,
-
-    MP_CMD_APPLY_PROFILE,
-
-    MP_CMD_LOAD_SCRIPT,
-
-    // Internal
-    MP_CMD_COMMAND_LIST, // list of sub-commands in args[0].v.p
-};
-
 // Executing this command will maybe abort playback (play something else, or quit).
 struct mp_cmd;
 bool mp_input_is_maybe_abort_cmd(struct mp_cmd *cmd);

input/cmd_parse.c

@@ -29,7 +29,6 @@
 #include "libmpv/client.h"
 
 const struct mp_cmd_def mp_cmd_list = {
-    .id = MP_CMD_COMMAND_LIST,
     .name = "list",
 };
 
@@ -87,7 +86,6 @@ static bool find_cmd(struct mp_log *log, struct mp_cmd *cmd, bstr name)
         if (strcmp(nname, mp_cmds[n].name) == 0) {
             cmd->def = &mp_cmds[n];
             cmd->name = (char *)cmd->def->name;
-            cmd->id = cmd->def->id;
             return true;
         }
     }
@@ -341,7 +339,6 @@ mp_cmd_t *mp_input_parse_cmd_(struct mp_log *log, bstr str, const char *loc)
             struct mp_cmd *list = talloc_ptrtype(NULL, list);
             talloc_set_destructor(list, destroy_cmd);
             *list = (struct mp_cmd) {
-                .id = mp_cmd_list.id,
                 .name = (char *)mp_cmd_list.name,
                 .def = &mp_cmd_list,
                 .original = bstrdup(list, original),

player/command.h

@@ -29,6 +29,25 @@ struct m_config_option;
 void command_init(struct MPContext *mpctx);
 void command_uninit(struct MPContext *mpctx);
 
+// Runtime context for a single command.
+struct mp_cmd_ctx {
+    struct MPContext *mpctx;
+    struct mp_cmd *cmd; // original command
+    // Fields from cmd (for convenience)
+    struct mp_cmd_arg *args;
+    int num_args;
+    const void *priv;   // cmd->def->priv
+    // OSD control
+    int on_osd;         // MP_ON_OSD_FLAGS;
+    bool msg_osd;       // OSD message requested
+    bool bar_osd;       // OSD bar requested
+    bool seek_msg_osd;  // same as above, but for seek commands
+    bool seek_bar_osd;
+    // Return values
+    bool success;       // true by default
+    struct mpv_node *result;
+};
+
 int run_command(struct MPContext *mpctx, struct mp_cmd *cmd, struct mpv_node *res);
 char *mp_property_expand_string(struct MPContext *mpctx, const char *str);
 char *mp_property_expand_escaped_string(struct MPContext *mpctx, const char *str);