BEGIN;
-- Keeping the encoded object in PostgreSQL makes object creation, bindings and
-- idempotency atomic. A future blob backend can replace bytes without changing
-- stable application URLs or canvas references.
CREATE TABLE canvas_assets (
 project text NOT NULL,
 workspace_id uuid NOT NULL,
 id uuid NOT NULL DEFAULT gen_random_uuid(),
 uploaded_by uuid NOT NULL,
 mime_type text NOT NULL CHECK(mime_type IN('image/png','image/jpeg','image/gif','image/webp')),
 bytes bytea NOT NULL CHECK(octet_length(bytes) BETWEEN 1 AND 20971520),
 width integer NOT NULL CHECK(width>0),
 height integer NOT NULL CHECK(height>0),
 digest text NOT NULL,
 idempotency_key uuid NOT NULL,
 created_at timestamptz NOT NULL DEFAULT now(),
 PRIMARY KEY(project,workspace_id,id),
 UNIQUE(project,workspace_id,uploaded_by,idempotency_key),
 FOREIGN KEY(project,workspace_id) REFERENCES workspaces ON DELETE CASCADE,
 FOREIGN KEY(project,uploaded_by) REFERENCES project_accounts
);
CREATE TABLE canvas_asset_bindings (
 project text NOT NULL,
 workspace_id uuid NOT NULL,
 asset_id uuid NOT NULL,
 board_id uuid NOT NULL,
 created_at timestamptz NOT NULL DEFAULT now(),
 PRIMARY KEY(project,workspace_id,asset_id,board_id),
 FOREIGN KEY(project,workspace_id,asset_id) REFERENCES canvas_assets ON DELETE RESTRICT,
 FOREIGN KEY(project,workspace_id,board_id) REFERENCES materials ON DELETE CASCADE
);
COMMIT;