-- 022_canonical_facts.sql — 0pt canonical structured observations (X-800 / Scrape).
--
-- 0pt owns normalized OBSERVED facts (what a source said, when, from which
-- artifact). L0RE owns epistemic propositions/assertions and projections; it
-- must consume these rows through this API/contract, never by writing here.
--
-- Conflict preservation is structural: the unique key includes source_ref and
-- observed_at, so two sources disagreeing about the same predicate are two
-- rows, never an overwrite. `status` records observed/supported/disputed/
-- retracted; reconciliation is a separate, explicit decision.
--
-- Tenant isolation: RLS is FORCEd and keyed on a transaction-local GUC that
-- only trusted server code sets (same pattern as 019_document_credit_rls.sql).

CREATE TABLE IF NOT EXISTS opt_canonical_entities (
  entity_id          UUID PRIMARY KEY,
  tenant_id          TEXT NOT NULL,
  entity_type        TEXT NOT NULL,            -- company|person|web_page|product|...
  identity_namespace TEXT NOT NULL,            -- url|orgnr|lei|gtin|...
  identity_value     TEXT NOT NULL,
  created_at         TIMESTAMPTZ NOT NULL DEFAULT now(),
  updated_at         TIMESTAMPTZ NOT NULL DEFAULT now(),
  UNIQUE (tenant_id, entity_type, identity_namespace, identity_value)
);
CREATE INDEX IF NOT EXISTS idx_canonical_entities_tenant_type
  ON opt_canonical_entities (tenant_id, entity_type);

CREATE TABLE IF NOT EXISTS opt_canonical_facts (
  fact_id            UUID PRIMARY KEY,
  tenant_id          TEXT NOT NULL,
  entity_id          UUID NOT NULL REFERENCES opt_canonical_entities (entity_id),
  predicate          TEXT NOT NULL,            -- e.g. web.title, product.price
  value_json         JSONB NOT NULL,
  value_type         TEXT NOT NULL,            -- string|number|boolean|date|json
  value_unit         TEXT,
  source_ref         TEXT NOT NULL,
  source_record_id   TEXT,
  st0re_artifact_id  TEXT,
  aud0_evidence_ref  TEXT,
  run_ref            TEXT,
  extractor_version  TEXT NOT NULL,
  observed_at        TIMESTAMPTZ NOT NULL,
  valid_from         TIMESTAMPTZ,
  valid_to           TIMESTAMPTZ,
  confidence         NUMERIC CHECK (confidence BETWEEN 0 AND 1),
  quality_status     TEXT NOT NULL DEFAULT 'unvalidated',  -- passed|warned|failed|unvalidated
  schema_version     TEXT NOT NULL DEFAULT '0pt.canonical_fact/v1',
  status             TEXT NOT NULL DEFAULT 'observed'
                     CHECK (status IN ('observed','supported','disputed','retracted')),
  created_at         TIMESTAMPTZ NOT NULL DEFAULT now(),
  UNIQUE (tenant_id, entity_id, predicate, source_ref, observed_at)
);
CREATE INDEX IF NOT EXISTS idx_canonical_facts_entity
  ON opt_canonical_facts (tenant_id, entity_id, predicate);
CREATE INDEX IF NOT EXISTS idx_canonical_facts_predicate
  ON opt_canonical_facts (tenant_id, predicate, observed_at DESC);

CREATE TABLE IF NOT EXISTS opt_canonical_relations (
  relation_id        UUID PRIMARY KEY,
  tenant_id          TEXT NOT NULL,
  subject_id         UUID NOT NULL REFERENCES opt_canonical_entities (entity_id),
  predicate          TEXT NOT NULL,            -- LINKS_TO|SOLD_BY|USES_SOFTWARE|...
  object_id          UUID NOT NULL REFERENCES opt_canonical_entities (entity_id),
  attributes_json    JSONB NOT NULL DEFAULT '{}'::jsonb,
  source_ref         TEXT NOT NULL,
  st0re_artifact_id  TEXT,
  aud0_evidence_ref  TEXT,
  run_ref            TEXT,
  extractor_version  TEXT NOT NULL,
  observed_at        TIMESTAMPTZ NOT NULL,
  valid_from         TIMESTAMPTZ,
  valid_to           TIMESTAMPTZ,
  confidence         NUMERIC CHECK (confidence BETWEEN 0 AND 1),
  schema_version     TEXT NOT NULL DEFAULT '0pt.canonical_relation/v1',
  created_at         TIMESTAMPTZ NOT NULL DEFAULT now(),
  UNIQUE (tenant_id, subject_id, predicate, object_id, source_ref, observed_at)
);
CREATE INDEX IF NOT EXISTS idx_canonical_relations_subject
  ON opt_canonical_relations (tenant_id, subject_id, predicate);
CREATE INDEX IF NOT EXISTS idx_canonical_relations_object
  ON opt_canonical_relations (tenant_id, object_id, predicate);

ALTER TABLE opt_canonical_entities ENABLE ROW LEVEL SECURITY;
ALTER TABLE opt_canonical_entities FORCE ROW LEVEL SECURITY;
DROP POLICY IF EXISTS opt_canonical_entities_tenant ON opt_canonical_entities;
CREATE POLICY opt_canonical_entities_tenant ON opt_canonical_entities
  USING (tenant_id = current_setting('app.opt_canonical_tenant_id', true))
  WITH CHECK (tenant_id = current_setting('app.opt_canonical_tenant_id', true));

ALTER TABLE opt_canonical_facts ENABLE ROW LEVEL SECURITY;
ALTER TABLE opt_canonical_facts FORCE ROW LEVEL SECURITY;
DROP POLICY IF EXISTS opt_canonical_facts_tenant ON opt_canonical_facts;
CREATE POLICY opt_canonical_facts_tenant ON opt_canonical_facts
  USING (tenant_id = current_setting('app.opt_canonical_tenant_id', true))
  WITH CHECK (tenant_id = current_setting('app.opt_canonical_tenant_id', true));

ALTER TABLE opt_canonical_relations ENABLE ROW LEVEL SECURITY;
ALTER TABLE opt_canonical_relations FORCE ROW LEVEL SECURITY;
DROP POLICY IF EXISTS opt_canonical_relations_tenant ON opt_canonical_relations;
CREATE POLICY opt_canonical_relations_tenant ON opt_canonical_relations
  USING (tenant_id = current_setting('app.opt_canonical_tenant_id', true))
  WITH CHECK (tenant_id = current_setting('app.opt_canonical_tenant_id', true));