schema: Upgrade for rotation configuration

schema/pgsql/upgrades/025.sql

@@ -0,0 +1,77 @@
+DO $$ BEGIN
+    CREATE TYPE rotation_type AS ENUM ( '24-7', 'partial', 'multi' );
+EXCEPTION
+    WHEN duplicate_object THEN null;
+END $$;
+
+CREATE TABLE IF NOT EXISTS rotation (
+    id bigserial,
+    schedule_id bigint NOT NULL REFERENCES schedule(id),
+    -- the lower the more important, starting at 0, avoids the need to re-index upon addition
+    priority integer NOT NULL,
+    name text NOT NULL,
+    mode rotation_type NOT NULL,
+    -- JSON with rotation-specific attributes
+    -- Needed exclusively by Web to simplify editing and visualisation
+    options text NOT NULL,
+
+    UNIQUE (schedule_id, priority), -- each schedule can only have one rotation with a given priority
+    CONSTRAINT pk_rotation PRIMARY KEY (id)
+);
+
+ALTER TABLE rule DROP COLUMN timeperiod_id;
+
+DROP TABLE IF EXISTS schedule_member;
+DROP TABLE IF EXISTS rotation_member;
+
+DROP TABLE IF EXISTS timeperiod_entry;
+
+DROP TABLE timeperiod;
+CREATE TABLE timeperiod (
+    id bigserial,
+    owned_by_rotation_id bigint REFERENCES rotation(id), -- nullable for future standalone timeperiods
+
+    CONSTRAINT pk_timeperiod PRIMARY KEY (id)
+);
+
+CREATE TABLE timeperiod_entry (
+    id bigserial,
+    timeperiod_id bigint NOT NULL REFERENCES timeperiod(id),
+    rotation_member_id bigint REFERENCES rotation_member(id), -- nullable for future standalone timeperiods
+    start_time bigint NOT NULL,
+    end_time bigint NOT NULL,
+    -- Is needed by icinga-notifications-web to prefilter entries, which matches until this time and should be ignored by the daemon.
+    until_time bigint,
+    timezone text NOT NULL, -- e.g. 'Europe/Berlin', relevant for evaluating rrule (DST changes differ between zones)
+    rrule text, -- recurrence rule (RFC5545)
+
+    CONSTRAINT pk_timeperiod_entry PRIMARY KEY (id)
+);
+
+CREATE TABLE rotation_member (
+    id bigserial,
+    rotation_id bigint NOT NULL REFERENCES rotation(id),
+    contact_id bigint REFERENCES contact(id),
+    contactgroup_id bigint REFERENCES contactgroup(id),
+    position integer NOT NULL,
+
+    UNIQUE (rotation_id, position), -- each position in a rotation can only be used once
+
+    -- Two UNIQUE constraints prevent duplicate memberships of the same contact or contactgroup in a single rotation.
+    -- Multiple NULLs are not considered to be duplicates, so rows with a contact_id but no contactgroup_id are
+    -- basically ignored in the UNIQUE constraint over contactgroup_id and vice versa. The CHECK constraint below
+    -- ensures that each row has only non-NULL values in one of these constraints.
+    UNIQUE (rotation_id, contact_id),
+    UNIQUE (rotation_id, contactgroup_id),
+    CHECK (num_nonnulls(contact_id, contactgroup_id) = 1),
+
+    CONSTRAINT pk_rotation_member PRIMARY KEY (id)
+);
+
+ALTER TABLE rule ADD COLUMN timeperiod_id bigint REFERENCES timeperiod(id);
+
+DO $$ BEGIN
+    DROP TYPE frequency_type;
+EXCEPTION
+    WHEN undefined_object THEN null;
+END $$;