refactor merge panel

1 files changed, 185 insertions, 0 deletions

diff --git a/pkg/gui/mergeconflicts/state.go b/pkg/gui/mergeconflicts/state.go
new file mode 100644
index 000000000..17ac02a0b
--- /dev/null
+++ b/pkg/gui/mergeconflicts/state.go
@@ -0,0 +1,185 @@
+package mergeconflicts
+
+import (
+	"bufio"
+	"os"
+	"strings"
+	"sync"
+
+	"github.com/golang-collections/collections/stack"
+	"github.com/jesseduffield/lazygit/pkg/utils"
+)
+
+type Selection int
+
+const (
+	TOP Selection = iota
+	BOTTOM
+	BOTH
+)
+
+// mergeConflict : A git conflict with a start middle and end corresponding to line
+// numbers in the file where the conflict bars appear
+type mergeConflict struct {
+	start  int
+	middle int
+	end    int
+}
+
+type State struct {
+	sync.Mutex
+	conflictIndex int
+	conflictTop   bool
+	conflicts     []*mergeConflict
+	EditHistory   *stack.Stack
+}
+
+func NewState() *State {
+	return &State{
+		Mutex:         sync.Mutex{},
+		conflictIndex: 0,
+		conflictTop:   true,
+		conflicts:     []*mergeConflict{},
+		EditHistory:   stack.New(),
+	}
+}
+
+func (s *State) SelectTopOption() {
+	s.conflictTop = true
+}
+
+func (s *State) SelectBottomOption() {
+	s.conflictTop = false
+}
+
+func (s *State) SelectNextConflict() {
+	if s.conflictIndex < len(s.conflicts)-1 {
+		s.conflictIndex++
+	}
+}
+
+func (s *State) SelectPrevConflict() {
+	if s.conflictIndex > 0 {
+		s.conflictIndex--
+	}
+}
+
+func (s *State) PushFileSnapshot(content string) {
+	s.EditHistory.Push(content)
+}
+
+func (s *State) PopFileSnapshot() (string, bool) {
+	if s.EditHistory.Len() == 0 {
+		return "", false
+	}
+
+	return s.EditHistory.Pop().(string), true
+}
+
+func (s *State) currentConflict() *mergeConflict {
+	if len(s.conflicts) == 0 {
+		return nil
+	}
+
+	return s.conflicts[s.conflictIndex]
+}
+
+func (s *State) SetConflictsFromCat(cat string) {
+	s.setConflicts(findConflicts(cat))
+}
+
+func findConflicts(content string) []*mergeConflict {
+	conflicts := make([]*mergeConflict, 0)
+
+	if content == "" {
+		return conflicts
+	}
+
+	var newConflict *mergeConflict
+	for i, line := range utils.SplitLines(content) {
+		trimmedLine := strings.TrimPrefix(line, "++")
+		switch trimmedLine {
+		case "<<<<<<< HEAD", "<<<<<<< MERGE_HEAD", "<<<<<<< Updated upstream", "<<<<<<< ours":
+			newConflict = &mergeConflict{start: i}
+		case "=======":
+			newConflict.middle = i
+		default:
+			if strings.HasPrefix(trimmedLine, ">>>>>>> ") {
+				newConflict.end = i
+				conflicts = append(conflicts, newConflict)
+			}
+		}
+
+	}
+	return conflicts
+}
+
+func (s *State) setConflicts(conflicts []*mergeConflict) {
+	s.conflicts = conflicts
+
+	if s.conflictIndex > len(s.conflicts)-1 {
+		s.conflictIndex = len(s.conflicts) - 1
+	} else if s.conflictIndex < 0 {
+		s.conflictIndex = 0
+	}
+}
+
+func (s *State) NoConflicts() bool {
+	return len(s.conflicts) == 0
+}
+
+func (s *State) Selection() Selection {
+	if s.conflictTop {
+		return TOP
+	} else {
+		return BOTTOM
+	}
+}
+
+func (s *State) IsFinalConflict() bool {
+	return len(s.conflicts) == 1
+}
+
+func (s *State) Reset() {
+	s.EditHistory = stack.New()
+}
+
+func (s *State) GetConflictMiddle() int {
+	return s.currentConflict().middle
+}
+
+func (s *State) ContentAfterConflictResolve(path string, selection Selection) (bool, string, error) {
+	conflict := s.currentConflict()
+	if conflict == nil {
+		return false, "", nil
+	}
+
+	file, err := os.Open(path)
+	if err != nil {
+		return false, "", err
+	}
+	defer file.Close()
+
+	reader := bufio.NewReader(file)
+	content := ""
+	for i := 0; true; i++ {
+		line, err := reader.ReadString('\n')
+		if err != nil {
+			break
+		}
+		if !isIndexToDelete(i, conflict, selection) {
+			content += line
+		}
+	}
+
+	return true, content, nil
+}
+
+func isIndexToDelete(i int, conflict *mergeConflict, selection Selection) bool {
+	return i == conflict.middle ||
+		i == conflict.start ||
+		i == conflict.end ||
+		selection != BOTH &&
+			(selection == BOTTOM && i > conflict.start && i < conflict.middle) ||
+		(selection == TOP && i > conflict.middle && i < conflict.end)
+}