-- Migration 092: Group invitations (v0.302 Lot S2.2)
-- Admin/moderator can invite users to join a group

CREATE TABLE IF NOT EXISTS group_invitations (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    group_id UUID NOT NULL REFERENCES groups(id) ON DELETE CASCADE,
    inviter_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    invitee_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    status VARCHAR(20) NOT NULL DEFAULT 'pending' CHECK (status IN ('pending', 'accepted', 'declined')),
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    UNIQUE(group_id, invitee_id)
);

CREATE INDEX IF NOT EXISTS idx_group_invitations_group_id ON group_invitations(group_id);
CREATE INDEX IF NOT EXISTS idx_group_invitations_invitee_id ON group_invitations(invitee_id);