// Package status defines the domain model shared across gitflow: how a Git
// repository's state is captured, classified, and summarised after a scan.
package status

import "time"

// RepoStatus classifies the overall health of a repository at scan time.
//
// The zero value is StatusUnknown, an invalid/unset state, so a zero-valued
// RepoInfo can never be mistaken for a real scan result.
type RepoStatus int

const (
	StatusUnknown  RepoStatus = iota // 0 — invalid/unset
	StatusClean                      // 1 — working tree clean, in sync
	StatusModified                   // 2 — staged, modified, or untracked files
	StatusAhead                      // 3 — local commits not yet pushed
	StatusBehind                     // 4 — remote commits not yet pulled
	StatusDiverged                   // 5 — both ahead of and behind upstream
	StatusDetached                   // 6 — HEAD points at a commit, not a branch
	StatusBare                       // 7 — bare repository, no working tree
	StatusError                      // 8 — could not be scanned
)

// String returns a lowercase, human-readable label for the status.
func (s RepoStatus) String() string {
	switch s {
	case StatusClean:
		return "clean"
	case StatusModified:
		return "modified"
	case StatusAhead:
		return "ahead"
	case StatusBehind:
		return "behind"
	case StatusDiverged:
		return "diverged"
	case StatusDetached:
		return "detached"
	case StatusBare:
		return "bare"
	case StatusError:
		return "error"
	default:
		return "unknown"
	}
}

// NeedsAttention reports whether the repository asks for human action.
func (s RepoStatus) NeedsAttention() bool {
	return s != StatusClean && s != StatusUnknown
}

// RepoInfo is a full snapshot of a single repository at scan time.
type RepoInfo struct {
	Path           string // absolute path to the repository root
	Name           string // base directory name, for display
	RemoteURL      string // fetch URL of the first remote, if any
	Branch         string // current branch name; "(detached)" when detached
	Detached       bool   // HEAD is detached from any branch
	Status         RepoStatus
	StagedFiles    []string // files with staged changes
	ModifiedFiles  []string // files with unstaged changes
	UntrackedFiles []string // untracked files or directories
	AheadBy        int      // commits ahead of upstream
	BehindBy       int      // commits behind upstream
	StashCount     int      // number of stashes
	Error          string   // scan error detail; non-empty when Status is StatusError
}

// FileCount returns the total number of files with any local change.
func (r RepoInfo) FileCount() int {
	return len(r.StagedFiles) + len(r.ModifiedFiles) + len(r.UntrackedFiles)
}

// ScanResult is the outcome of one scan pass over a set of repositories.
type ScanResult struct {
	ScannedAt time.Time // when the scan ran
	ParentDir string    // the directory that was scanned
	Repos     []RepoInfo
}

// Summary aggregates per-repository counters for the whole result.
type Summary struct {
	Total     int // repositories scanned
	Clean     int // status clean, no action needed
	Attention int // status not clean (modified, ahead, behind, diverged, detached, bare)
	Errored   int // status error (scan failed)
	Staged    int // files staged across all repos
	Modified  int // files modified across all repos
	Untracked int // untracked files across all repos
}

// Summary computes the aggregate counters for the result.
func (r ScanResult) Summary() Summary {
	s := Summary{Total: len(r.Repos)}
	for _, repo := range r.Repos {
		switch repo.Status {
		case StatusClean:
			s.Clean++
		case StatusError:
			s.Errored++
		case StatusUnknown:
			// Neither clean nor actionable; not counted.
		default:
			s.Attention++
		}
		s.Staged += len(repo.StagedFiles)
		s.Modified += len(repo.ModifiedFiles)
		s.Untracked += len(repo.UntrackedFiles)
	}
	return s
}

// NeedsAttention lists repositories whose status is anything but clean.
func (r ScanResult) NeedsAttention() []RepoInfo {
	out := make([]RepoInfo, 0, len(r.Repos))
	for _, repo := range r.Repos {
		if repo.Status.NeedsAttention() {
			out = append(out, repo)
		}
	}
	return out
}