upload

type APIPresigner struct {
	BaseURL string
	Config  config.Config
	HTTP    *http.Client
}

type Lifecycle struct {
	// Init starts a multipart upload and returns the S3 upload id.
	Init func(ctx context.Context, fileID string) (string, error)
	// Complete finalises the upload from the collected part ETags.
	Complete func(ctx context.Context, fileID, uploadID string, parts []Part) error
	// Abort discards an incomplete upload so its parts stop accruing S3
	// storage charges.
	Abort func(ctx context.Context, fileID, uploadID string) error
}

type Part struct {
	ETag       string `json:"ETag"`
	PartNumber int    `json:"PartNumber"`
}

type PartPlan struct {
	// Number is the 1-based S3 part number.
	Number int
	// Offset is the byte offset of the chunk within the file.
	Offset int64
	// Size is the length of the chunk in bytes.
	Size int64
}

type PresignRequest struct {
	UploadID    string `json:"upload_id"`
	PartNumbers []int  `json:"part_numbers"`
}

type PresignResponse struct {
	UploadID string         `json:"upload_id"`
	URLs     []PresignedURL `json:"urls"`
}

type PresignedURL struct {
	PartNumber int    `json:"part_number"`
	URL        string `json:"url"`
	ExpiresAt  string `json:"expires_at"`
}

type Presigner interface {
	Presign(ctx context.Context, fileID, uploadID string, partNumbers []int) ([]PresignedURL, error)
}

type StatusError struct {
	Code int
	Body string
}

type Uploader struct {
	// Presigner obtains presigned PUT URLs. Required.
	Presigner Presigner
	// HTTP is used for the PUTs to S3. Defaults to http.DefaultClient. It must
	// not be the Management API client: presigned URLs carry their own
	// credentials and reject extra auth headers.
	HTTP *http.Client
	// PartSize overrides PartSize. Only tests should set this; S3 rejects
	// non-final parts under 5 MiB.
	PartSize int64
	// PresignBatch is how many URLs to request per presign call.
	PresignBatch int
	// MaxAttempts bounds transient retries per part.
	MaxAttempts int
	// MaxRefreshes bounds presigned-URL refreshes per part.
	MaxRefreshes int
	// RetryDelay is the base backoff between transient retries.
	RetryDelay time.Duration
	// Progress receives human-readable progress lines. Callers should point
	// this at stderr so stdout stays machine-parseable. Nil discards.
	Progress io.Writer
	// Clock reads the current time when judging whether a presigned URL is
	// still fresh. Defaults to time.Now; tests override it to travel forward.
	Clock func() time.Time
}