-- TODO: We are still in prototyping phase. Database migration is not
-- implemented and layout can change at any time.

CREATE TABLE IF NOT EXISTS `user` (
    `uid`           INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
    `userkey`       BLOB NOT NULL UNIQUE,
    `permission`    INTEGER NOT NULL DEFAULT 0
) STRICT;

-- The highest bit of `rid` will be set for peer chat room.
-- So simply comparing it against 0 can filter them out.
CREATE TABLE IF NOT EXISTS `room` (
    `rid`       INTEGER NOT NULL PRIMARY KEY,
    -- RoomAttrs::PEER_CHAT
    `attrs`     INTEGER NOT NULL
                CHECK ((`attrs` & 0x10000 == 0x10000) == `rid` < 0),
    `title`     TEXT
                CHECK ((`title` ISNULL) == `rid` < 0),

    `peer1`     INTEGER REFERENCES `user` ON DELETE RESTRICT
                CHECK ((`peer1` NOTNULL) == `rid` < 0),
    `peer2`     INTEGER REFERENCES `user` ON DELETE RESTRICT
                CHECK ((`peer2` NOTNULL AND `peer1` <= `peer2`) IS `rid` < 0)
) STRICT;

CREATE UNIQUE INDEX IF NOT EXISTS `ix_peer_chat` ON `room`
    (`peer1`, `peer2`)
    WHERE `rid` < 0;

CREATE TABLE IF NOT EXISTS `room_member` (
    `rid`           INTEGER NOT NULL REFERENCES `room` ON DELETE CASCADE,
    `uid`           INTEGER NOT NULL REFERENCES `user` ON DELETE RESTRICT,
    `permission`    INTEGER NOT NULL,
    -- Optionally references `room_item`(`cid`).
    `last_seen_cid` INTEGER NOT NULL DEFAULT 0,
    PRIMARY KEY (`rid`, `uid`)
) STRICT;

CREATE INDEX IF NOT EXISTS `ix_member_room` ON `room_member`
    (`uid` ASC, `rid` ASC, `permission`, `last_seen_cid`);

CREATE TABLE IF NOT EXISTS `room_item` (
    `cid`       INTEGER NOT NULL PRIMARY KEY,
    `rid`       INTEGER NOT NULL REFERENCES `room` ON DELETE CASCADE,
    `uid`       INTEGER NOT NULL REFERENCES `user` ON DELETE RESTRICT,
    `timestamp` INTEGER NOT NULL,
    `nonce`     INTEGER NOT NULL,
    `sig`       BLOB NOT NULL,
    `rich_text` TEXT NOT NULL
) STRICT;

CREATE INDEX IF NOT EXISTS `room_latest_item` ON `room_item` (`rid` ASC, `cid` DESC);