-- +goose Up
CREATE TABLE evidence_assets (
  id TEXT PRIMARY KEY,
  upload_key TEXT NOT NULL,
  task_id TEXT NOT NULL,
  attempt_id TEXT NOT NULL,
  kind TEXT NOT NULL CHECK (kind = 'SKU_PANEL_GATE_1'),
  privacy_tier TEXT NOT NULL CHECK (privacy_tier = 'INTERNAL_RAW'),
  sha256 TEXT NOT NULL CHECK (
    length(sha256) = 64
    AND sha256 NOT GLOB '*[^0-9a-f]*'
  ),
  byte_size INTEGER NOT NULL CHECK (
    typeof(byte_size) = 'integer'
    AND byte_size > 0
    AND byte_size <= 10485760
  ),
  content_type TEXT NOT NULL CHECK (content_type = 'image/png'),
  width_px INTEGER NOT NULL CHECK (
    typeof(width_px) = 'integer'
    AND width_px > 0
    AND width_px <= 8192
  ),
  height_px INTEGER NOT NULL CHECK (
    typeof(height_px) = 'integer'
    AND height_px > 0
    AND height_px <= 8192
  ),
  storage_key TEXT NOT NULL CHECK (
    storage_key = substr(sha256, 1, 2) || '/' || sha256 || '.png'
  ),
  uploaded_by_device_id TEXT NOT NULL CHECK (trim(uploaded_by_device_id) <> ''),
  captured_at TEXT NOT NULL CHECK (trim(captured_at) <> ''),
  created_at TEXT NOT NULL CHECK (trim(created_at) <> ''),
  CHECK (width_px * height_px <= 16777216),
  UNIQUE (uploaded_by_device_id, upload_key),
  FOREIGN KEY (task_id, attempt_id) REFERENCES purchase_attempts(task_id, id)
);

CREATE INDEX evidence_assets_task_time_idx
ON evidence_assets (task_id, captured_at, created_at, id);

-- +goose Down
-- 已写入的内部原图是审计事实，回滚迁移不得静默删除它们。
CREATE TABLE evidence_downgrade_guard (
  valid INTEGER NOT NULL CHECK (valid = 1)
);

INSERT INTO evidence_downgrade_guard (valid)
SELECT CASE WHEN (SELECT COUNT(*) FROM evidence_assets) = 0 THEN 1 ELSE 0 END;

DROP TABLE evidence_downgrade_guard;
DROP TABLE evidence_assets;