-- 0004_investigation_bureau.sql
--
-- W3.1 — Foundation for the Investigation Bureau agentic runtime.
--
-- Adds the 7 tables, sequences, RLS policies, audit trigger, and the
-- minimal-privilege `investigator` role used by the new `investigator-runtime`
-- container. None of these existed before; the previous "8 detectives" was
-- branding-only — this is where it becomes a real motor.
--
-- IMPORTANT (same as migration 0003): apply as `supabase_admin`, not
-- `postgres`, because public.chunks / .entities are owned by supabase_admin.
-- A non-supabase_admin postgres user gets "must be owner" on the FK to
-- public.chunks below.
--
-- Idempotent. Safe to re-run.
--
-- Spec references: docs/adrs/ADR-002-investigation-bureau-runtime.md
--                  + agentic-layer-spec.md (sec 3.3, 4, 5, 9).

BEGIN;

-- ─────────────────────────────────────────────────────────────────────────
-- ID sequences. We allocate human-readable IDs like E-0042, H-0007, R-0028,
-- W-0001, G-0001 by nextval'ing these from the writer tools.
-- ─────────────────────────────────────────────────────────────────────────
CREATE SEQUENCE IF NOT EXISTS public.evidence_id_seq START 1;
CREATE SEQUENCE IF NOT EXISTS public.hypothesis_id_seq START 1;
CREATE SEQUENCE IF NOT EXISTS public.contradiction_id_seq START 1;
CREATE SEQUENCE IF NOT EXISTS public.witness_id_seq START 1;
CREATE SEQUENCE IF NOT EXISTS public.gap_id_seq START 1;
CREATE SEQUENCE IF NOT EXISTS public.residual_uncertainty_id_seq START 1;

-- ─────────────────────────────────────────────────────────────────────────
-- 1. investigation_jobs — the queue + audit trail of every investigation.
--    Workers LISTEN on the channel below and UPDATE status as they progress.
-- ─────────────────────────────────────────────────────────────────────────
CREATE TABLE IF NOT EXISTS public.investigation_jobs (
  job_id          UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  kind            TEXT NOT NULL,
  payload         JSONB NOT NULL DEFAULT '{}'::jsonb,
  triggered_by    TEXT,
  status          TEXT NOT NULL DEFAULT 'queued'
                  CHECK (status IN ('queued','running','complete','failed','aborted')),
  worker_id       TEXT,
  budget_used_usd NUMERIC(10,4) DEFAULT 0,
  started_at      TIMESTAMPTZ,
  finished_at     TIMESTAMPTZ,
  outputs         JSONB,
  error           TEXT,
  created_at      TIMESTAMPTZ NOT NULL DEFAULT NOW()
);
CREATE INDEX IF NOT EXISTS investigation_jobs_status_idx
  ON public.investigation_jobs (status, created_at);

CREATE OR REPLACE FUNCTION public.notify_new_investigation_job() RETURNS TRIGGER AS $$
BEGIN
  PERFORM pg_notify('investigation_jobs', NEW.job_id::TEXT);
  RETURN NEW;
END
$$ LANGUAGE plpgsql;

DROP TRIGGER IF EXISTS investigation_jobs_notify ON public.investigation_jobs;
CREATE TRIGGER investigation_jobs_notify
  AFTER INSERT ON public.investigation_jobs
  FOR EACH ROW EXECUTE FUNCTION public.notify_new_investigation_job();

-- ─────────────────────────────────────────────────────────────────────────
-- 2. evidence — Locard's chain of custody, one row per discovered evidence.
--    `source_chunk_pk` FK to public.chunks ensures we never store an
--    evidence pointing at a chunk that doesn't exist. ON DELETE RESTRICT so a
--    chunk can't be silently removed under our feet.
-- ─────────────────────────────────────────────────────────────────────────
CREATE TABLE IF NOT EXISTS public.evidence (
  evidence_pk        BIGSERIAL PRIMARY KEY,
  evidence_id        TEXT UNIQUE NOT NULL,
  verbatim_excerpt   TEXT NOT NULL,
  source_chunk_pk    BIGINT REFERENCES public.chunks(chunk_pk) ON DELETE RESTRICT,
  source_page_id     TEXT NOT NULL,
  bbox               JSONB,
  grade              TEXT NOT NULL CHECK (grade IN ('A','B','C')),
  custody_steps      JSONB NOT NULL,
  custody_gaps       JSONB,
  confidence_band    TEXT CHECK (confidence_band IN ('high','medium','low','speculation')),
  related_hypotheses JSONB DEFAULT '[]'::jsonb,
  created_by         TEXT NOT NULL DEFAULT 'locard@detective',
  created_at         TIMESTAMPTZ NOT NULL DEFAULT NOW()
);
CREATE INDEX IF NOT EXISTS evidence_grade_idx ON public.evidence (grade);
CREATE INDEX IF NOT EXISTS evidence_chunk_idx ON public.evidence (source_chunk_pk);

-- ─────────────────────────────────────────────────────────────────────────
-- 3. hypotheses — Holmes-style propositions with prior/posterior + Tetlock band.
-- ─────────────────────────────────────────────────────────────────────────
CREATE TABLE IF NOT EXISTS public.hypotheses (
  hypothesis_pk    BIGSERIAL PRIMARY KEY,
  hypothesis_id    TEXT UNIQUE NOT NULL,
  question         TEXT NOT NULL,
  position         TEXT NOT NULL,
  argument_for     TEXT,
  argument_against TEXT,
  evidence_refs    JSONB DEFAULT '[]'::jsonb,
  prior            NUMERIC(4,3),
  posterior        NUMERIC(4,3),
  confidence_band  TEXT CHECK (confidence_band IN ('high','medium','low','speculation')),
  status           TEXT NOT NULL DEFAULT 'open'
                   CHECK (status IN ('open','closed','dormant','superseded')),
  superseded_by    TEXT REFERENCES public.hypotheses(hypothesis_id) ON DELETE SET NULL,
  created_by       TEXT NOT NULL DEFAULT 'holmes@detective',
  reviewed_by      TEXT,
  created_at       TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  updated_at       TIMESTAMPTZ NOT NULL DEFAULT NOW()
);
CREATE INDEX IF NOT EXISTS hypotheses_status_idx ON public.hypotheses (status);

-- Trigram index is nice-to-have for full-text similarity over the question
-- field. Wrap in a DO block so missing pg_trgm extension doesn't kill the run.
DO $$
BEGIN
  IF EXISTS (SELECT 1 FROM pg_extension WHERE extname='pg_trgm') THEN
    EXECUTE 'CREATE INDEX IF NOT EXISTS hypotheses_question_trgm ON public.hypotheses USING GIN (question gin_trgm_ops)';
  END IF;
END
$$;

-- ─────────────────────────────────────────────────────────────────────────
-- 4. contradictions — Dupin-style cross-chunk contradiction graph nodes.
-- ─────────────────────────────────────────────────────────────────────────
CREATE TABLE IF NOT EXISTS public.contradictions (
  contradiction_pk   BIGSERIAL PRIMARY KEY,
  contradiction_id   TEXT UNIQUE NOT NULL,     -- R-NNNN (R = relation, per CLAUDE.md naming)
  topic              TEXT NOT NULL,
  chunks             JSONB NOT NULL,           -- [{chunk_pk, position, ...}]
  detected_by        TEXT NOT NULL DEFAULT 'dupin@detective',
  resolution_status  TEXT NOT NULL DEFAULT 'open'
                     CHECK (resolution_status IN ('open','resolved','irreconcilable')),
  notes              TEXT,
  created_at         TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- ─────────────────────────────────────────────────────────────────────────
-- 5. witnesses — Poirot-style witness credibility analyses, FK to people entity.
-- ─────────────────────────────────────────────────────────────────────────
CREATE TABLE IF NOT EXISTS public.witnesses (
  witness_pk         BIGSERIAL PRIMARY KEY,
  witness_id         TEXT UNIQUE NOT NULL,     -- W-NNNN
  person_entity_pk   BIGINT REFERENCES public.entities(entity_pk) ON DELETE RESTRICT,
  credibility        TEXT CHECK (credibility IN ('high','medium','low','speculation')),
  access_to_event    TEXT,                     -- prose: how did they witness it?
  bias_notes         TEXT,
  corroboration_refs JSONB DEFAULT '[]'::jsonb, -- [{evidence_id, doc_id, ...}]
  verdict            TEXT,                     -- one-line summary
  created_by         TEXT NOT NULL DEFAULT 'poirot@detective',
  created_at         TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- ─────────────────────────────────────────────────────────────────────────
-- 6. gaps — known unknowns: what was NOT possible to determine.
-- ─────────────────────────────────────────────────────────────────────────
CREATE TABLE IF NOT EXISTS public.gaps (
  gap_pk             BIGSERIAL PRIMARY KEY,
  gap_id             TEXT UNIQUE NOT NULL,     -- G-NNNN
  description        TEXT NOT NULL,
  scope              JSONB,                    -- {doc_id?, hypothesis_id?, ...}
  suggested_next_move TEXT,                    -- "FOIA request X" / "consult archive Y"
  status             TEXT NOT NULL DEFAULT 'open'
                     CHECK (status IN ('open','partial','closed')),
  created_by         TEXT NOT NULL DEFAULT 'chief-detective',
  created_at         TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- ─────────────────────────────────────────────────────────────────────────
-- 7. residual_uncertainties — Schneier red-team + Taleb anti-fragile notes.
-- ─────────────────────────────────────────────────────────────────────────
CREATE TABLE IF NOT EXISTS public.residual_uncertainties (
  ru_pk              BIGSERIAL PRIMARY KEY,
  ru_id              TEXT UNIQUE NOT NULL,     -- RU-NNNN
  hypothesis_id      TEXT REFERENCES public.hypotheses(hypothesis_id) ON DELETE CASCADE,
  scope              TEXT NOT NULL,            -- 'hypothesis' | 'document' | 'global'
  description        TEXT NOT NULL,
  black_swan_check   TEXT,                     -- Taleb: what would invalidate this?
  failure_mode       TEXT,                     -- Schneier: how does this break?
  created_by         TEXT NOT NULL,
  created_at         TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- ─────────────────────────────────────────────────────────────────────────
-- RLS — all new tables are public read; writes only via the investigator role.
-- ─────────────────────────────────────────────────────────────────────────
ALTER TABLE public.investigation_jobs     ENABLE ROW LEVEL SECURITY;
ALTER TABLE public.evidence               ENABLE ROW LEVEL SECURITY;
ALTER TABLE public.hypotheses             ENABLE ROW LEVEL SECURITY;
ALTER TABLE public.contradictions         ENABLE ROW LEVEL SECURITY;
ALTER TABLE public.witnesses              ENABLE ROW LEVEL SECURITY;
ALTER TABLE public.gaps                   ENABLE ROW LEVEL SECURITY;
ALTER TABLE public.residual_uncertainties ENABLE ROW LEVEL SECURITY;

DROP POLICY IF EXISTS investigation_jobs_read ON public.investigation_jobs;
DROP POLICY IF EXISTS evidence_read           ON public.evidence;
DROP POLICY IF EXISTS hypotheses_read         ON public.hypotheses;
DROP POLICY IF EXISTS contradictions_read     ON public.contradictions;
DROP POLICY IF EXISTS witnesses_read          ON public.witnesses;
DROP POLICY IF EXISTS gaps_read               ON public.gaps;
DROP POLICY IF EXISTS residual_uncertainties_read ON public.residual_uncertainties;

CREATE POLICY investigation_jobs_read     ON public.investigation_jobs     FOR SELECT USING (TRUE);
CREATE POLICY evidence_read               ON public.evidence               FOR SELECT USING (TRUE);
CREATE POLICY hypotheses_read             ON public.hypotheses             FOR SELECT USING (TRUE);
CREATE POLICY contradictions_read         ON public.contradictions         FOR SELECT USING (TRUE);
CREATE POLICY witnesses_read              ON public.witnesses              FOR SELECT USING (TRUE);
CREATE POLICY gaps_read                   ON public.gaps                   FOR SELECT USING (TRUE);
CREATE POLICY residual_uncertainties_read ON public.residual_uncertainties FOR SELECT USING (TRUE);

GRANT SELECT ON
  public.investigation_jobs,
  public.evidence,
  public.hypotheses,
  public.contradictions,
  public.witnesses,
  public.gaps,
  public.residual_uncertainties
  TO anon, authenticated;

-- ─────────────────────────────────────────────────────────────────────────
-- `investigator` role — minimum privilege. The new container connects with
-- THIS role, NOT service_role. Per gate #1 of sa-security-engineer.
--
-- Capability matrix:
--   - SELECT on read corpus (chunks, entities, entity_mentions, relations,
--     documents) so the worker can answer questions.
--   - INSERT/UPDATE on the new write surfaces (jobs + 6 investigation tables).
--   - NO SELECT on auth.users, profiles, messages — the worker must never
--     see PII or chat content.
-- ─────────────────────────────────────────────────────────────────────────
DO $$
BEGIN
  IF NOT EXISTS (SELECT 1 FROM pg_roles WHERE rolname='investigator') THEN
    CREATE ROLE investigator WITH LOGIN
      CONNECTION LIMIT 4
      PASSWORD 'placeholder_set_by_bootstrap';  -- rotated by the deploy script
    -- ALTER ROLE investigator SET search_path = public, pg_catalog;
  END IF;
END
$$;

GRANT CONNECT ON DATABASE postgres TO investigator;
GRANT USAGE ON SCHEMA public TO investigator;

GRANT SELECT ON
  public.chunks,
  public.entities,
  public.entity_mentions,
  public.relations,
  public.documents
  TO investigator;

GRANT SELECT, INSERT, UPDATE ON
  public.investigation_jobs,
  public.evidence,
  public.hypotheses,
  public.contradictions,
  public.witnesses,
  public.gaps,
  public.residual_uncertainties
  TO investigator;

GRANT USAGE, SELECT, UPDATE ON
  public.evidence_id_seq,
  public.hypothesis_id_seq,
  public.contradiction_id_seq,
  public.witness_id_seq,
  public.gap_id_seq,
  public.residual_uncertainty_id_seq
  TO investigator;

COMMIT;