-- AP1.16a: Durchführungsplan — Action-Reihenfolge, kind, Abhängigkeiten

ALTER TABLE actions
    ADD COLUMN IF NOT EXISTS sort_order INT NOT NULL DEFAULT 0;

ALTER TABLE actions
    ADD COLUMN IF NOT EXISTS action_kind VARCHAR(32) NOT NULL DEFAULT 'delivery'
        CHECK (action_kind IN ('delivery', 'planning', 'review'));

CREATE INDEX idx_actions_initiative_sort
    ON actions(tenant_id, initiative_id, sort_order);

CREATE TABLE action_dependencies (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    tenant_id UUID NOT NULL REFERENCES tenants(id) ON DELETE CASCADE,
    initiative_id UUID NOT NULL REFERENCES initiatives(id) ON DELETE CASCADE,
    predecessor_action_id UUID NOT NULL REFERENCES actions(id) ON DELETE CASCADE,
    successor_action_id UUID NOT NULL REFERENCES actions(id) ON DELETE CASCADE,
    dependency_kind VARCHAR(32) NOT NULL DEFAULT 'requires'
        CHECK (dependency_kind IN ('requires', 'blocks', 'relates')),
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    UNIQUE (tenant_id, predecessor_action_id, successor_action_id, dependency_kind)
);

CREATE INDEX idx_action_deps_predecessor
    ON action_dependencies(tenant_id, predecessor_action_id);

CREATE INDEX idx_action_deps_successor
    ON action_dependencies(tenant_id, successor_action_id);

CREATE INDEX idx_action_deps_initiative
    ON action_dependencies(tenant_id, initiative_id);