lectio-ui reader: go-to-chapter jump (c)

Inside a book, 'c' opens a centered prompt showing the book's chapter
range (e.g. "1-21: ") and accepts a chapter number to jump straight there,
instead of scrolling (handy for Psalm 119 etc). Digits only, backspace
edits, Enter clamps to the valid range and opens that chapter at its top,
Esc cancels. New modeChapterJump + updateChapterJump/jumpToChapter/
viewChapterJump; i18n ReaderJumpChapter/ReaderJumpChapterKeys (en/pl) and
'c' added to the reading keybar. Only offered when the book has >1 chapter.

1 files changed, 106 insertions, 10 deletions

diff --git a/internal/tui/reader.go b/internal/tui/reader.go
index df92349..7f23f66 100644
--- a/internal/tui/reader.go
+++ b/internal/tui/reader.go
@@ -3,6 +3,7 @@ package tui
 import (
 	"fmt"
 	"sort"
+	"strconv"
 	"strings"
 
 	tea "github.com/charmbracelet/bubbletea"
@@ -21,11 +22,12 @@ import (
 type readerMode int
 
 const (
-	modePick      readerMode = iota
-	modeRead                 // scrolling chapter view
-	modeMarkVerse            // picking the verse to bookmark (highlighted cursor)
-	modeMark                 // typing an optional note for the chosen verse
-	modeBookmarks            // the saved-bookmarks list
+	modePick        readerMode = iota
+	modeRead                   // scrolling chapter view
+	modeMarkVerse              // picking the verse to bookmark (highlighted cursor)
+	modeMark                   // typing an optional note for the chosen verse
+	modeBookmarks              // the saved-bookmarks list
+	modeChapterJump            // typing a chapter number to jump to
 )
 
 // selStyle marks the picker's selected row (reverse video, legible on any theme).
@@ -70,11 +72,12 @@ type ReaderModel struct {
 	pickTop int   // first visible match (list scroll)
 
 	// reading
-	bookIdx  int   // index into books
-	chapters []int // sorted chapters for current book+version
-	chapPos  int   // index into chapters
-	verses   []bible.Verse
-	scroll   int
+	bookIdx     int   // index into books
+	chapters    []int // sorted chapters for current book+version
+	chapPos     int   // index into chapters
+	verses      []bible.Verse
+	scroll      int
+	chapJumpBuf string // digits typed in modeChapterJump
 
 	// bookmarks
 	store         *bookmarks.Store
@@ -218,6 +221,8 @@ func (m ReaderModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 			return m.updateMark(msg)
 		case modeBookmarks:
 			return m.updateBookmarks(msg)
+		case modeChapterJump:
+			return m.updateChapterJump(msg)
 		default:
 			return m.updateRead(msg)
 		}
@@ -302,6 +307,12 @@ func (m ReaderModel) updateRead(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 		return m.chapterStep(+1), nil
 	case "p", "[", "left", "h":
 		return m.chapterStep(-1), nil
+	case "c":
+		if len(m.chapters) > 1 {
+			m.mode = modeChapterJump
+			m.chapJumpBuf = ""
+		}
+		return m, nil
 	case "j", "down":
 		m.scroll = m.clampRead(m.scroll + 1)
 		return m, nil
@@ -457,6 +468,75 @@ func (m ReaderModel) updateBookmarks(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 	return m, nil
 }
 
+// updateChapterJump handles the go-to-chapter prompt: type digits, Enter jumps
+// (clamped to the book's chapter range), Esc cancels. Non-digit keys are
+// ignored so the buffer only ever holds a number.
+func (m ReaderModel) updateChapterJump(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
+	switch msg.Type {
+	case tea.KeyCtrlC:
+		return m, tea.Quit
+	case tea.KeyEsc:
+		m.mode = modeRead
+		m.chapJumpBuf = ""
+		return m, nil
+	case tea.KeyEnter:
+		m = m.jumpToChapter(m.chapJumpBuf)
+		m.chapJumpBuf = ""
+		m.mode = modeRead
+		return m, nil
+	case tea.KeyBackspace:
+		if r := []rune(m.chapJumpBuf); len(r) > 0 {
+			m.chapJumpBuf = string(r[:len(r)-1])
+		}
+		return m, nil
+	case tea.KeyRunes:
+		for _, r := range msg.Runes {
+			if r >= '0' && r <= '9' && len([]rune(m.chapJumpBuf)) < 4 {
+				m.chapJumpBuf += string(r)
+			}
+		}
+		return m, nil
+	}
+	return m, nil
+}
+
+// jumpToChapter parses buf as a chapter number, clamps it to the book's
+// chapter range, and opens that chapter at its top. An empty or non-numeric
+// buf is a no-op (the prompt just closes). Because the corpora number chapters
+// contiguously, the clamped number always names an existing chapter; if a book
+// ever had a gap, the nearest existing chapter at or after it is used.
+func (m ReaderModel) jumpToChapter(buf string) ReaderModel {
+	if len(m.chapters) == 0 {
+		return m
+	}
+	n, err := strconv.Atoi(strings.TrimSpace(buf))
+	if err != nil {
+		return m
+	}
+	lo, hi := m.chapters[0], m.chapters[len(m.chapters)-1]
+	if n < lo {
+		n = lo
+	}
+	if n > hi {
+		n = hi
+	}
+	pos := len(m.chapters) - 1
+	for i, c := range m.chapters {
+		if c >= n {
+			pos = i
+			break
+		}
+	}
+	if pos == m.chapPos {
+		return m
+	}
+	m.chapPos = pos
+	m.scroll = 0
+	m = m.loadVerses()
+	m.savePlace()
+	return m
+}
+
 // currentChapter is the chapter number currently shown (0 if none loaded).
 func (m ReaderModel) currentChapter() int {
 	if len(m.chapters) > 0 && m.chapPos < len(m.chapters) {
@@ -735,11 +815,27 @@ func (m ReaderModel) View() string {
 		return m.viewMark()
 	case modeBookmarks:
 		return m.viewBookmarks()
+	case modeChapterJump:
+		return m.viewChapterJump()
 	default: // modeRead + modeMarkVerse (verse cursor highlighted in the reading)
 		return m.viewRead()
 	}
 }
 
+// viewChapterJump renders the go-to-chapter prompt as a prominent centered
+// dialog showing the book's valid chapter range and the digits typed so far.
+func (m ReaderModel) viewChapterJump() string {
+	ui := i18n.Get(m.cfg.UILanguage)
+	lo, hi := 0, 0
+	if len(m.chapters) > 0 {
+		lo, hi = m.chapters[0], m.chapters[len(m.chapters)-1]
+	}
+	title := modalTitleStyle.Render(fmt.Sprintf("%s %s", m.books[m.bookIdx].Name, ui.ReaderJumpChapter))
+	prompt := fmt.Sprintf("%d-%d: %s▏", lo, hi, m.chapJumpBuf)
+	inner := title + "\n\n" + prompt + "\n\n" + citationStyle.Render(ui.ReaderJumpChapterKeys)
+	return m.modal(inner)
+}
+
 // viewMark renders the bookmark note/tags box as a prominent centered dialog.
 // The note and tags wrap (with a hanging indent) within a bounded width, so a
 // long note flows down inside the box instead of overrunning the border.