schema: Upgrade for rotation configuration

schema/pgsql/upgrades/025.sql

@@ -0,0 +1,71 @@
+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),
+    priority integer NOT NULL, -- the lower the higher the priority, starting at 0
+    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,
+
+    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),
+    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 (
+    rotation_id bigint NOT NULL REFERENCES rotation(id),
+    contact_id bigint REFERENCES contact(id),
+    contactgroup_id bigint REFERENCES contactgroup(id),
+    timeperiod_entry_id bigint NOT NULL REFERENCES timeperiod_entry(id),
+    position integer NOT NULL,
+
+    -- There is no PRIMARY KEY in that table as either contact_id or contactgroup_id should be allowed to be NULL.
+    -- Instead, there are two UNIQUE constraints that prevent duplicate entries. 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)
+);
+
+ALTER TABLE rule ADD COLUMN timeperiod_id bigint REFERENCES timeperiod(id);
+
+DO $$ BEGIN
+    DROP TYPE frequency_type;
+EXCEPTION
+    WHEN undefined_object THEN null;
+END $$;