-- Approval Workflow Schema (VS-03)
-- Maker-Checker approval gates for model activation
-- INSERT-only, PIT-tracked with correlation_id

CREATE SCHEMA IF NOT EXISTS model_operations;

-- Approval proposals (DRAFT → PROPOSED → APPROVED → ACTIVE)
CREATE TABLE IF NOT EXISTS model_operations.approval_proposals (
    id UUID PRIMARY KEY,
    model_id UUID NOT NULL REFERENCES model_operations.models(id),
    status VARCHAR(50) NOT NULL,
    created_by VARCHAR(255) NOT NULL,
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    justification TEXT NOT NULL,
    effective_at DATE NOT NULL,
    proposed_at TIMESTAMPTZ,
    approved_by VARCHAR(255),
    approved_at TIMESTAMPTZ,
    approval_notes TEXT,
    activated_by VARCHAR(255),
    activated_at TIMESTAMPTZ,
    published_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    revision INT NOT NULL DEFAULT 1,
    correlation_id UUID NOT NULL
);

CREATE INDEX IF NOT EXISTS idx_approval_proposals_model_id ON model_operations.approval_proposals(model_id);
CREATE INDEX IF NOT EXISTS idx_approval_proposals_status ON model_operations.approval_proposals(status);
CREATE INDEX IF NOT EXISTS idx_approval_proposals_created_by ON model_operations.approval_proposals(created_by);

-- Approval evidence (PBO/DSR/OOS artifacts)
CREATE TABLE IF NOT EXISTS model_operations.approval_evidence (
    id UUID PRIMARY KEY,
    approval_proposal_id UUID NOT NULL REFERENCES model_operations.approval_proposals(id),
    evidence_type VARCHAR(50) NOT NULL,
    evidence_url TEXT NOT NULL,
    reviewer_comment TEXT,
    published_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    correlation_id UUID NOT NULL
);

CREATE INDEX IF NOT EXISTS idx_approval_evidence_proposal_id ON model_operations.approval_evidence(approval_proposal_id);

-- Approval events (audit trail)
CREATE TABLE IF NOT EXISTS model_operations.approval_events (
    id UUID PRIMARY KEY,
    approval_proposal_id UUID NOT NULL REFERENCES model_operations.approval_proposals(id),
    event_type VARCHAR(50) NOT NULL,
    actor_email VARCHAR(255) NOT NULL,
    event_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    details JSONB,
    published_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    correlation_id UUID NOT NULL
);

CREATE INDEX IF NOT EXISTS idx_approval_events_proposal_id ON model_operations.approval_events(approval_proposal_id);
CREATE INDEX IF NOT EXISTS idx_approval_events_type ON model_operations.approval_events(event_type);