assemble

type Assembler struct {
	GitHub   GitHub
	Git      Git
	Sessions Sessions
	Images   ImageFetcher
	// Fetcher fetches a pull request commit the clone lacks from the remote
	// whose URL names the pull request's repository. Nil fetches nothing, and
	// a missing commit is a MissingCommitError with the fetch to run.
	Fetcher Fetcher
	// Redactor masks the bundle's text; nil builds the default one.
	Redactor *bundle.Redactor
	// Warn receives one line for each input that was left out and why; nil
	// discards them. Bundle JSON never goes here.
	Warn io.Writer
}

type Fetcher interface {
	ResolvePull(ctx context.Context, pr gitlocal.PullRequest) (gitlocal.Pull, error)
}

type FrozenSessions interface {
	Sessions
	FrozenEvidence(ctx context.Context, commits []gitlocal.Commit, maxPrompts, maxCommandEvents int) ([]bundle.Session, error)
}

type Git interface {
	// ResolveCommit expands a commit id the clone holds; a commit it lacks
	// is gitlocal.ErrObjectNotFound. It never fetches.
	ResolveCommit(ctx context.Context, id string) (string, error)
	// RemoteURLs lists the clone's configured remote URLs, from its
	// configuration only.
	RemoteURLs(ctx context.Context) ([]gitlocal.Remote, error)
	// Commits lists the commits reachable from head and not from base,
	// oldest first.
	Commits(ctx context.Context, base, head string) ([]gitlocal.Commit, error)
	// Compare diffs the merge base of base and head against head.
	Compare(ctx context.Context, base, head string) (bundle.Comparison, error)
	// TextPatch diffs paths between exactly the two commits given.
	TextPatch(ctx context.Context, baseOID, headOID string, paths ...string) ([]byte, error)
	// Blob reads a file at a commit; a missing one is bundle.ErrNotFound.
	Blob(ctx context.Context, commitOID, path string) ([]byte, error)
	bundle.PinnedExport
}

type GitHub interface {
	Fetch(ctx context.Context, repo github.Repository, number int, opts github.FetchOptions) (github.Evidence, error)
}

type GroupMember struct {
	Number int
	Result Result
}

type GroupResult struct {
	Result
	// HunkMembers names, for each hunk of the merged diff, the members whose
	// own diff holds it, in member order: a change two members both make is
	// one hunk of both.
	HunkMembers map[string][]int
}

type ImageFetcher func(ctx context.Context, fetchURL string, maxBytes int64) ([]byte, error)

type Limits struct {
	Caps     bundle.Caps
	Checkout bundle.CheckoutConfig
	// MaxImages and MaxImageBytes bound captured description and session images.
	MaxImages     int
	MaxImageBytes int64
}

type LocalSessions struct {
	// Dir is the clone, or a directory inside it.
	Dir string
	// Stores narrows or redirects the session stores, and carries the
	// directories the repository used to live at.
	Stores sessions.Options
	// Warn receives a line for each store file that could not be read.
	Warn io.Writer
	// Repo, when set, is the clone containing Dir, already open; reads of it
	// share its private repository instead of opening their own.
	Repo *gitlocal.Repo
}

type MissingCommitError struct {
	// Role is "head" or "base".
	Role   string
	SHA    string
	Number int
	// BaseRef is the base branch's name.
	BaseRef string
	// Remote is the clone's remote whose URL names the pull request's
	// repository; "" when none does, and Repository is then named in the hint.
	Remote     string
	Repository string
	// Fetch is why fetching the commit failed; nil when it was not fetched.
	Fetch error
}

type Request struct {
	Repository github.Repository
	Number     int
	Limits     Limits
	// Previous is the pull request's current document, in the form the
	// hosted builder carries it into the next version's bundle; nil when
	// there is none, as for "the bundle assembler".
	Previous *bundle.PreviousVersion
	// Checkout, when not nil, receives the checkout archive "the generation pipeline"
	// reads: a gzip-compressed tar holding the head/ and merge-base/ trees,
	// as bundle.UnpackCheckout unpacks it. Nil exports the same trees to
	// nowhere, since what the budget omits still shapes the bundle.
	Checkout io.Writer
	// Attachments, when not nil, receives the description images as a plain
	// tar of attachments/<id>.<ext>, as bundle.UnpackAttachments unpacks it.
	Attachments io.Writer
	// Facts builds the bundle a pull request's facts are read from
	// (review.BuildFacts), which no model reads: the head/ and merge-base/
	// trees are not exported and no description image is downloaded, so
	// hunks keep their text whatever the checkout budget, and the bundle has
	// no attachments. Checkout and Attachments must then be nil.
	Facts bool
}

type Result struct {
	// Bundle is the redacted, trimmed bundle with its Digest and
	// MaskedSpanCount set.
	Bundle bundle.Bundle
	// JSON is the bundle as written: the encoding the digest is the SHA-256
	// of, plus a final newline.
	JSON []byte
	// Head, Base and MergeBase are the commits the bundle describes.
	Head, Base, MergeBase string
	// Images are the captured images in the attachments archive.
	Images []bundle.DescriptionImage
}

type SessionImage struct {
	Bytes  []byte
	Origin bundle.ImageOrigin
}

type SessionImages interface {
	ImageEvidence(context.Context, []bundle.Session, int, int64) ([]SessionImage, []string, error)
}

type Sessions interface {
	Evidence(ctx context.Context, commits []gitlocal.Commit, maxPrompts, maxCommandEvents int) ([]bundle.Session, error)
}