refactor(parser): simplify ParseLine logic for completed, priority, and date parsing

- Refactor ParseLine to use token-based parsing for completed status,
  priority, and dates.
- Improve handling of priority and creation date for both completed and
  incomplete tasks.

internal/parser/parser.go

@@ -35,8 +35,12 @@ func (t Task) PriorityAsRemind() int {
 	if p < 'A' || p > 'Z' {
 		return 5000
 	}
-	// A=9999, Z=0, linear scale
-	return 9999 - int(p-'A')*400
+	step := 9999 / 25 // 399
+	val := 9999 - int(p-'A')*step
+	if p == 'Z' {
+		return 0
+	}
+	return val
 }
 
 func (t Task) MarshalJSON() ([]byte, error) {
@@ -60,11 +64,9 @@ func (t Task) MarshalJSON() ([]byte, error) {
 }
 
 var (
-	dateRe        = regexp.MustCompile(`^\d{4}-\d{2}-\d{2}$`)
-	priorityHead  = regexp.MustCompile(`^\([A-Z]\)\s+`)
-	completedHead = regexp.MustCompile(`^x\s+`)
-	spaceRe       = regexp.MustCompile(`\s+`)
-	dateLayout    = "2006-01-02"
+	dateRe     = regexp.MustCompile(`^\d{4}-\d{2}-\d{2}$`)
+	spaceRe    = regexp.MustCompile(`\s+`)
+	dateLayout = "2006-01-02"
 	// Protocols to exclude as metadata keys
 	protocols = map[string]struct{}{
 		"http":   {},
@@ -115,48 +117,56 @@ func ParseLine(line string) (Task, error) {
 	}
 
 	working := strings.TrimSpace(line)
+	toks := splitTokens(working)
+	i := 0
 
 	// 1) Completed?
-	if completedHead.MatchString(working) {
+	if i < len(toks) && toks[i] == "x" {
 		t.Completed = true
-		working = completedHead.ReplaceAllString(working, "")
-		toks := splitTokens(working)
-		consumed := 0
-		if len(toks) > 0 && dateRe.MatchString(toks[0]) {
-			if dt, err := time.Parse(dateLayout, toks[0]); err == nil {
+		i++
+		// 2) Completion date
+		if i < len(toks) && dateRe.MatchString(toks[i]) {
+			if dt, err := time.Parse(dateLayout, toks[i]); err == nil {
 				t.CompletionDate = &dt
-				consumed = 1
+				i++
 			}
 		}
-		if consumed < len(toks) && dateRe.MatchString(toks[consumed]) {
-			if dt, err := time.Parse(dateLayout, toks[consumed]); err == nil {
+		// 3) Creation date
+		if i < len(toks) && dateRe.MatchString(toks[i]) {
+			if dt, err := time.Parse(dateLayout, toks[i]); err == nil {
 				t.CreationDate = &dt
-				consumed++
-			}
-		}
-		if consumed > 0 {
-			working = strings.TrimSpace(strings.Join(toks[consumed:], " "))
-		}
-	} else {
-		if priorityHead.MatchString(working) {
-			if len(working) >= 3 {
-				r := rune(working[1])
-				t.Priority = &r
-			}
-			working = priorityHead.ReplaceAllString(working, "")
-		}
-		toks := splitTokens(working)
-		if len(toks) > 0 && dateRe.MatchString(toks[0]) {
-			if dt, err := time.Parse(dateLayout, toks[0]); err == nil {
-				t.CreationDate = &dt
-				working = strings.TrimSpace(strings.Join(toks[1:], " "))
+				i++
 			}
 		}
 	}
 
-	tokens := splitTokens(working)
-	descParts := make([]string, 0, len(tokens))
-	for _, tok := range tokens {
+	// 4) Priority (can appear after x, dates)
+	if i < len(toks) && len(toks[i]) == 3 && toks[i][0] == '(' && toks[i][2] == ')' && toks[i][1] >= 'A' && toks[i][1] <= 'Z' {
+		r := rune(toks[i][1])
+		t.Priority = &r
+		i++
+	}
+
+	// 5) If not completed, check for priority at start
+	if !t.Completed {
+		if i < len(toks) && len(toks[i]) == 3 && toks[i][0] == '(' && toks[i][2] == ')' && toks[i][1] >= 'A' && toks[i][1] <= 'Z' {
+			r := rune(toks[i][1])
+			t.Priority = &r
+			i++
+		}
+		// Creation date for incomplete tasks
+		if i < len(toks) && dateRe.MatchString(toks[i]) {
+			if dt, err := time.Parse(dateLayout, toks[i]); err == nil {
+				t.CreationDate = &dt
+				i++
+			}
+		}
+	}
+
+	// 6) Parse remaining tokens
+	descParts := make([]string, 0)
+	for ; i < len(toks); i++ {
+		tok := toks[i]
 		if strings.HasPrefix(tok, "+") && len(tok) > 1 {
 			t.Projects = append(t.Projects, tok[1:])
 			continue
@@ -170,7 +180,6 @@ func ParseLine(line string) (Task, error) {
 			k, v := parts[0], parts[1]
 			if k != "" && v != "" && !isProtocolKey(k) {
 				t.Metadata[k] = v
-				// If the field is due:YYYY-MM-DD, also parse it as DueDate
 				if k == "due" && dateRe.MatchString(v) {
 					if dt, err := time.Parse(dateLayout, v); err == nil {
 						t.DueDate = &dt
@@ -179,7 +188,6 @@ func ParseLine(line string) (Task, error) {
 				continue
 			}
 		}
-		// else part of description
 		descParts = append(descParts, tok)
 	}
 	t.Description = strings.TrimSpace(strings.Join(descParts, " "))