1 files changed, 136 insertions, 0 deletions
diff --git a/src/player.c b/src/player.c
index e09c574..9367a14 100644
--- a/src/player.c
+++ b/src/player.c
@@ -1,2 +1,138 @@
 #include "player.h"
 
+#include "list.h"
+#include "data.h"
+
+bool
+player_history_contains(struct track *cmp, int depth)
+{
+	struct link *link;
+	struct track *track;
+
+	link = list_back(&player.history);
+	while (LIST_INNER(link) && depth-- > 0) {
+		track = UPCAST(link, struct track, link_hs);
+		if (track == cmp)
+			return true;
+		link = link->prev;
+	}
+
+	return false;
+}
+
+struct track *
+playlist_track_next_unused(struct link *start)
+{
+	struct track *track;
+	struct link *link;
+	bool in_history;
+	int len;
+
+	track = NULL;
+
+	len = list_len(&player.playlist);
+	if (!len) return NULL;
+
+	link = start;
+	while (LIST_INNER(link)) {
+		track = UPCAST(link, struct track, link_pl);
+
+		in_history = player_history_contains(track, len - 2);
+		if (track != player.track && !in_history)
+			break;
+
+		link = link->next;
+		if (!LIST_INNER(link))
+			link = list_front(&player.playlist);
+
+		if (link == start)
+			return NULL;
+	}
+
+	return track;
+}
+
+struct track *
+player_next_from_playlist(void)
+{
+	struct link *link;
+	int index;
+
+	if (list_empty(&player.playlist))
+		return NULL;
+
+	if (player.shuffle) {
+		index = rand() % list_len(&player.playlist);
+		link = list_at(&player.playlist, index);
+		return playlist_track_next_unused(link);
+	} else {
+		if (player.track && link_inuse(&player.track->link_pl)) {
+			index = list_index(&player.playlist,
+				&player.track->link_pl);
+			if (index < 0) PANIC();
+			if (++index == list_len(&player.playlist))
+				return NULL;
+		} else {
+			index = 0;
+		}
+		link = list_at(&player.playlist, index);
+		return UPCAST(link, struct track, link_pl);
+	}
+
+	return NULL;
+}
+
+int
+player_prev(void)
+{
+	struct link *next;
+	struct track *track;
+
+	if (list_empty(&player.history))
+		return PLAYER_STATUS_ERR;
+
+	if (!player.track || !link_inuse(&player.track->link_hs)) {
+		next = list_back(&player.history);
+	} else if (LIST_INNER(player.track->link_hs.prev)) {
+		next = player.track->link_hs.prev;
+	} else {
+		return PLAYER_STATUS_ERR;
+	}
+
+	track = UPCAST(next, struct track, link_hs);
+	player_play_track(track, false);
+
+	return PLAYER_STATUS_OK;
+}
+
+int
+player_next(void)
+{
+	struct track *next_track;
+	struct link *link;
+	bool new_entry;
+
+	if (player.track && link_inuse(&player.track->link_hs)
+			&& LIST_INNER(player.track->link_hs.next)) {
+		next_track = UPCAST(player.track->link_hs.next,
+			struct track, link_hs);
+		new_entry = false;
+	} else if (!list_empty(&player.queue)) {
+		link = list_pop_front(&player.queue);
+		next_track = UPCAST(link, struct track, link_pq);
+		new_entry = true;
+	} else {
+		next_track = player_next_from_playlist();
+		if (!next_track) goto clear;
+		new_entry = true;
+	}
+
+	player_play_track(next_track, new_entry);
+	return PLAYER_STATUS_OK;
+
+clear:
+	player_clear_track();
+	return PLAYER_STATUS_ERR;
+}
+
+