-- Migration 003: Operations (signals, checks, approvals, status)
-- Signals are dual entities (entities row + signals table for indexed querying).

CREATE TABLE check_defs (
    entity_id     UUID PRIMARY KEY REFERENCES entities(id),
    target_id     UUID REFERENCES entities(id),
    target_type   TEXT REFERENCES entity_types(name),
    kind          TEXT NOT NULL,
    config        JSONB NOT NULL DEFAULT '{}',
    interval_s    INTEGER NOT NULL DEFAULT 600,
    timeout_s     INTEGER NOT NULL DEFAULT 10,
    zone          TEXT,
    enabled       BOOLEAN NOT NULL DEFAULT true,
    updated_at    TIMESTAMPTZ NOT NULL DEFAULT now()
);

CREATE TABLE signals (
    entity_id         UUID PRIMARY KEY REFERENCES entities(id),
    kind              TEXT NOT NULL,
    severity          TEXT NOT NULL CHECK (severity IN ('info','warning','critical')),
    target_entity_id  UUID REFERENCES entities(id),
    check_id          UUID REFERENCES check_defs(entity_id),
    evidence          TEXT,
    likely_cause      TEXT,
    state             TEXT NOT NULL DEFAULT 'raised',
    occurrence_count  INTEGER NOT NULL DEFAULT 1,
    first_seen_at     TIMESTAMPTZ NOT NULL DEFAULT now(),
    last_seen_at      TIMESTAMPTZ NOT NULL DEFAULT now(),
    flap_count        INTEGER NOT NULL DEFAULT 0,
    hold_down_until   TIMESTAMPTZ,
    mute_until        TIMESTAMPTZ,
    created_at        TIMESTAMPTZ NOT NULL DEFAULT now(),
    updated_at        TIMESTAMPTZ NOT NULL DEFAULT now()
);
-- At most ONE open signal per (target, kind) — repeats update the open row
CREATE UNIQUE INDEX uq_signals_open ON signals(target_entity_id, kind)
    WHERE state NOT IN ('resolved','failed');
CREATE INDEX idx_signals_state ON signals(state);

CREATE TABLE approvals (
    entity_id         UUID PRIMARY KEY REFERENCES entities(id),
    subject_entity_id UUID REFERENCES entities(id),
    action            TEXT NOT NULL,
    risk_class        TEXT NOT NULL,
    kind              TEXT NOT NULL DEFAULT 'execution',
    payload           JSONB,
    status            TEXT NOT NULL DEFAULT 'pending',
    token_hash        TEXT,
    expires_at        TIMESTAMPTZ NOT NULL,
    decided_at        TIMESTAMPTZ,
    decided_by        UUID REFERENCES entities(id),
    created_at        TIMESTAMPTZ NOT NULL DEFAULT now()
);

CREATE TABLE entity_status (
    entity_id     UUID PRIMARY KEY REFERENCES entities(id),
    health        TEXT NOT NULL DEFAULT 'unknown',
    last_check_at TIMESTAMPTZ,
    details       JSONB NOT NULL DEFAULT '{}',
    updated_at    TIMESTAMPTZ NOT NULL DEFAULT now()
);

CREATE TABLE idempotency_keys (
    key           TEXT NOT NULL,
    actor         TEXT NOT NULL,
    request_hash  TEXT NOT NULL,
    response_code INTEGER,
    response_body JSONB,
    created_at    TIMESTAMPTZ NOT NULL DEFAULT now(),
    PRIMARY KEY (actor, key)
);