CREATE EXTENSION IF NOT EXISTS pg_trgm;
CREATE EXTENSION IF NOT EXISTS pgcrypto;

CREATE OR REPLACE FUNCTION update_updated_at_column()
RETURNS TRIGGER AS $$
BEGIN
    NEW.updated_at = CURRENT_TIMESTAMP;
    RETURN NEW;
END;
$$ LANGUAGE plpgsql;

CREATE TABLE IF NOT EXISTS users (
    id BIGINT GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
    username VARCHAR(50) NOT NULL,
    signup_method SMALLINT NOT NULL,
    role SMALLINT NOT NULL,
    avatar_file_reference_id BIGINT NULL REFERENCES file_references(id) ON DELETE SET NULL,
    created_at TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
    version INTEGER NOT NULL DEFAULT 0,
    deleted_at TIMESTAMPTZ NULL
);

CREATE UNIQUE INDEX IF NOT EXISTS idx_users_username ON users(LOWER(username)) WHERE deleted_at IS NULL;
CREATE INDEX IF NOT EXISTS idx_users_created_at ON users(created_at);
CREATE INDEX IF NOT EXISTS idx_users_deleted_at ON users(deleted_at) WHERE deleted_at IS NOT NULL;
CREATE INDEX IF NOT EXISTS idx_users_role ON users(role) WHERE deleted_at IS NULL;
CREATE INDEX IF NOT EXISTS idx_users_username_trgm ON users USING gin(username gin_trgm_ops) WHERE deleted_at IS NULL;

CREATE TRIGGER update_users_updated_at
    BEFORE UPDATE ON users
    FOR EACH ROW
    EXECUTE FUNCTION update_updated_at_column();