BEGIN;

CREATE TABLE alert_routing_policy (
    id                         uuid PRIMARY KEY DEFAULT gen_random_uuid(),
    public_id                  uuid NOT NULL UNIQUE DEFAULT gen_random_uuid(),
    tenant_id                  uuid NOT NULL REFERENCES tenant(id),
    category                   varchar(20) NOT NULL CHECK (category IN ('BUSINESS','TECHNICAL','SECURITY','COST')),
    severity                   varchar(16) NOT NULL CHECK (severity IN ('CRITICAL','HIGH','MEDIUM','LOW')),
    version_no                 integer NOT NULL CHECK (version_no>0),
    status                     varchar(16) NOT NULL DEFAULT 'ACTIVE' CHECK (status IN ('ACTIVE','RETIRED')),
    receiver_group             varchar(120) NOT NULL,
    response_minutes           integer NOT NULL CHECK (response_minutes BETWEEN 1 AND 10080),
    escalation_after_minutes   integer NOT NULL CHECK (escalation_after_minutes BETWEEN 1 AND 10080),
    escalation_receiver_group  varchar(120) NOT NULL,
    runbook_ref                varchar(300) NOT NULL,
    change_summary             varchar(500) NOT NULL,
    created_by                 uuid NOT NULL REFERENCES user_account(id),
    retired_at                 timestamptz,
    row_version                bigint NOT NULL DEFAULT 1 CHECK (row_version>0),
    created_at                 timestamptz NOT NULL DEFAULT now(),
    updated_at                 timestamptz NOT NULL DEFAULT now(),
    CONSTRAINT alert_route_version_unique UNIQUE (tenant_id,category,severity,version_no)
);
CREATE UNIQUE INDEX alert_route_active_unique ON alert_routing_policy(tenant_id,category,severity) WHERE status='ACTIVE';

CREATE TABLE alert_silence (
    id                  uuid PRIMARY KEY DEFAULT gen_random_uuid(),
    public_id           uuid NOT NULL UNIQUE DEFAULT gen_random_uuid(),
    tenant_id           uuid NOT NULL REFERENCES tenant(id),
    rule_code           varchar(100),
    category            varchar(20) CHECK (category IN ('BUSINESS','TECHNICAL','SECURITY','COST')),
    resource_type       varchar(80),
    resource_public_id  uuid,
    matcher             jsonb NOT NULL DEFAULT '{}'::jsonb,
    reason              varchar(500) NOT NULL,
    starts_at           timestamptz NOT NULL,
    ends_at             timestamptz NOT NULL,
    created_by          uuid NOT NULL REFERENCES user_account(id),
    revoked_by          uuid REFERENCES user_account(id),
    revoked_at          timestamptz,
    row_version         bigint NOT NULL DEFAULT 1 CHECK (row_version>0),
    created_at          timestamptz NOT NULL DEFAULT now(),
    updated_at          timestamptz NOT NULL DEFAULT now(),
    CONSTRAINT alert_silence_scope CHECK (rule_code IS NOT NULL OR category IS NOT NULL OR resource_public_id IS NOT NULL),
    CONSTRAINT alert_silence_window CHECK (ends_at>starts_at)
);
CREATE INDEX alert_silence_active_idx ON alert_silence(tenant_id,starts_at,ends_at) WHERE revoked_at IS NULL;

CREATE TABLE alert_incident (
    id                      uuid PRIMARY KEY DEFAULT gen_random_uuid(),
    public_id               uuid NOT NULL UNIQUE DEFAULT gen_random_uuid(),
    tenant_id               uuid NOT NULL REFERENCES tenant(id),
    rule_code               varchar(100) NOT NULL,
    category                varchar(20) NOT NULL CHECK (category IN ('BUSINESS','TECHNICAL','SECURITY','COST')),
    severity                varchar(16) NOT NULL CHECK (severity IN ('CRITICAL','HIGH','MEDIUM','LOW')),
    status                  varchar(24) NOT NULL DEFAULT 'OPEN' CHECK (status IN ('OPEN','ACKNOWLEDGED','MITIGATED','RESOLVED','SILENCED')),
    fingerprint             varchar(200) NOT NULL,
    title                   varchar(200) NOT NULL,
    summary                 varchar(1000) NOT NULL,
    resource_type           varchar(80),
    resource_public_id      uuid,
    correlation_request_id  varchar(128),
    routing_policy_id       uuid REFERENCES alert_routing_policy(id),
    current_owner_id        uuid REFERENCES user_account(id),
    first_detected_at       timestamptz NOT NULL,
    last_detected_at        timestamptz NOT NULL,
    occurrence_count        bigint NOT NULL DEFAULT 1 CHECK (occurrence_count>0),
    acknowledged_at         timestamptz,
    mitigated_at            timestamptz,
    resolved_at             timestamptz,
    silenced_until          timestamptz,
    escalated_at            timestamptz,
    row_version             bigint NOT NULL DEFAULT 1 CHECK (row_version>0),
    created_at              timestamptz NOT NULL DEFAULT now(),
    updated_at              timestamptz NOT NULL DEFAULT now()
);
CREATE UNIQUE INDEX alert_incident_active_fingerprint ON alert_incident(tenant_id,fingerprint) WHERE status<>'RESOLVED';
CREATE INDEX alert_incident_queue_idx ON alert_incident(tenant_id,status,severity,last_detected_at DESC);

CREATE TABLE alert_action (
    id                uuid PRIMARY KEY DEFAULT gen_random_uuid(),
    public_id         uuid NOT NULL UNIQUE DEFAULT gen_random_uuid(),
    tenant_id         uuid NOT NULL REFERENCES tenant(id),
    incident_id       uuid NOT NULL REFERENCES alert_incident(id) ON DELETE CASCADE,
    action_type       varchar(24) NOT NULL CHECK (action_type IN ('DETECTED','ACKNOWLEDGED','ASSIGNED','SILENCED','MITIGATED','RESOLVED','REOPENED','ESCALATED','COMMENTED')),
    from_status       varchar(24),
    to_status         varchar(24),
    actor_type        varchar(16) NOT NULL CHECK (actor_type IN ('system','user')),
    actor_user_id     uuid REFERENCES user_account(id),
    note              varchar(1000) NOT NULL,
    created_at        timestamptz NOT NULL DEFAULT now()
);
CREATE INDEX alert_action_incident_time_idx ON alert_action(incident_id,created_at,id);

COMMIT;