-- IHF Phase 4: Outcome Observation and Antifragility Loop
-- Adds: deployment_records, outcome_signals (append-only), change_evaluations

CREATE TABLE deployment_records (
    id UUID DEFAULT uuid_generate_v4() PRIMARY KEY NOT NULL,
    impl_ref_id UUID REFERENCES implementation_change_references(id) ON DELETE SET NULL,
    decision_id UUID NOT NULL REFERENCES decision_records(id) ON DELETE RESTRICT,
    version_ref TEXT NOT NULL,
    deployed_at TIMESTAMP WITH TIME ZONE DEFAULT now() NOT NULL,
    deployed_by UUID REFERENCES users(id),
    notes TEXT,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT now() NOT NULL
);

CREATE INDEX deployment_records_decision_id_idx ON deployment_records (decision_id);
CREATE INDEX deployment_records_deployed_at_idx ON deployment_records (deployed_at DESC);

CREATE TABLE outcome_signals (
    id UUID DEFAULT uuid_generate_v4() PRIMARY KEY NOT NULL,
    widget_id UUID NOT NULL REFERENCES widgets(id) ON DELETE CASCADE,
    deployment_id UUID NOT NULL REFERENCES deployment_records(id) ON DELETE CASCADE,
    signal_type TEXT NOT NULL,
    value NUMERIC,
    observed_at TIMESTAMP WITH TIME ZONE DEFAULT now() NOT NULL
);

CREATE INDEX outcome_signals_widget_id_idx ON outcome_signals (widget_id);
CREATE INDEX outcome_signals_deployment_id_idx ON outcome_signals (deployment_id);
CREATE INDEX outcome_signals_observed_at_idx ON outcome_signals (observed_at DESC);

CREATE OR REPLACE FUNCTION prevent_outcome_signal_mutation()
RETURNS TRIGGER AS $$
BEGIN
    RAISE EXCEPTION 'outcome_signals is append-only: UPDATE and DELETE are not permitted';
END;
$$ LANGUAGE plpgsql;

CREATE TRIGGER outcome_signals_no_update
    BEFORE UPDATE ON outcome_signals
    FOR EACH ROW EXECUTE FUNCTION prevent_outcome_signal_mutation();

CREATE TRIGGER outcome_signals_no_delete
    BEFORE DELETE ON outcome_signals
    FOR EACH ROW EXECUTE FUNCTION prevent_outcome_signal_mutation();

CREATE TABLE change_evaluations (
    id UUID DEFAULT uuid_generate_v4() PRIMARY KEY NOT NULL,
    deployment_id UUID NOT NULL REFERENCES deployment_records(id) ON DELETE CASCADE,
    decision_id UUID REFERENCES decision_records(id) ON DELETE SET NULL,
    score SMALLINT NOT NULL CHECK (score BETWEEN 1 AND 5),
    rationale TEXT NOT NULL,
    evaluated_by UUID REFERENCES users(id),
    evaluated_at TIMESTAMP WITH TIME ZONE DEFAULT now() NOT NULL,
    UNIQUE (deployment_id)
);

CREATE INDEX change_evaluations_deployment_id_idx ON change_evaluations (deployment_id);