host

type Comment struct {
	ID     string
	Author string
	Body   string
	// Timestamp is RFC3339 or similar human-readable string.
	Timestamp string
}

type CreatePRInput struct {
	Title        string
	Description  string
	SourceBranch string
	TargetBranch string
	Draft        bool
	Reviewers    []string
}

type Host interface {
	// CreatePR creates a new pull request and returns the created PR.
	CreatePR(ctx context.Context, in CreatePRInput) (*PR, error)
	// GetPR fetches a pull request by ID.
	GetPR(ctx context.Context, id string) (*PR, error)
	// ListPRs lists pull requests. If mine is true, filter to the authed user.
	ListPRs(ctx context.Context, state string, mine bool) ([]*PR, error)
	// MergePR merges a pull request by ID. Returns the merge commit SHA.
	MergePR(ctx context.Context, id string) (string, error)
	// CommentPR posts a comment on a PR. replyTo is a comment ID (empty = top-level).
	CommentPR(ctx context.Context, id, text, replyTo string) error
	// GetBuildStatus returns the CI state for a commit SHA.
	GetBuildStatus(ctx context.Context, sha string) (string, error)
	// GetReviewers returns the list of reviewer usernames for a PR.
	GetReviewers(ctx context.Context, id string) ([]string, error)
	// UpdatePR updates title, description, and adds reviewers to an existing PR.
	UpdatePR(ctx context.Context, id, title, description string, addReviewers []string) error
	// CurrentUser returns the authenticated username.
	CurrentUser(ctx context.Context) (string, error)
}

type PR struct {
	ID           string
	URL          string
	Title        string
	Description  string
	State        string // OPEN | MERGED | DECLINED | SUPERSEDED
	Draft        bool
	SourceBranch string
	TargetBranch string
	HeadSHA      string
	Reviewers    []string
	Approvals    []string // users who approved
	Blockers     []string // blocker comment IDs
	CIState      string   // SUCCESSFUL | FAILED | INPROGRESS | UNKNOWN
	LastComment  *Comment
}