CREATE TYPE conversation_kind AS ENUM ('dm', 'group', 'channel');

CREATE TABLE conversations (
    id           UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    workspace_id UUID REFERENCES workspaces(id) ON DELETE CASCADE,
    kind         conversation_kind NOT NULL,
    name         TEXT,
    is_public    BOOLEAN NOT NULL DEFAULT true,
    created_by   UUID NOT NULL REFERENCES users(id),
    created_at   TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    updated_at   TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    deleted_at   TIMESTAMPTZ
);

CREATE TABLE conversation_members (
    conversation_id UUID        NOT NULL REFERENCES conversations(id) ON DELETE CASCADE,
    user_id         UUID        NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    joined_at       TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    PRIMARY KEY (conversation_id, user_id)
);

CREATE INDEX conversations_workspace_id_idx       ON conversations(workspace_id);
CREATE INDEX conversation_members_user_id_idx     ON conversation_members(user_id);