Feature -- minimal pdf browser

added minimal pdf browser, still experimental (like everything here lol!)
 Changes to be committed:
	new file:   cmd/browse.go
	modified:   document/document.go
	modified:   go-poppler/page.go

3 files changed, 339 insertions, 10 deletions

diff --git a/cmd/browse.go b/cmd/browse.go
new file mode 100644
index 0000000..a6abac0
--- /dev/null
+++ b/cmd/browse.go
@@ -0,0 +1,310 @@
+/*
+Copyright © 2025 NAME HERE <EMAIL ADDRESS>
+*/
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/gdamore/tcell/v2"
+	"github.com/rivo/tview"
+	"github.com/scrotadamus/ghligh/document"
+	"github.com/spf13/cobra"
+)
+
+type browsableDoc struct {
+	doc         *document.GhlighDoc
+	currentPage int
+
+	title  string
+	author string
+	nPages int
+}
+
+func (d *browsableDoc) getCurrentPage() int {
+	return d.currentPage
+}
+func (d *browsableDoc) setCurrentPage(i int) {
+	switch {
+	case i >= d.nPages:
+		d.currentPage = d.nPages - 1
+	case i < 0:
+		d.currentPage = 0
+	default:
+		d.currentPage = i
+	}
+}
+
+func openBrowsableDoc(path string) (*browsableDoc, error) {
+	// open and init document
+	doc, err := document.Open(path)
+	if err != nil {
+		return nil, err
+	}
+
+	b := &browsableDoc{
+		doc:         doc,
+		currentPage: 0,
+		title:       doc.Info().Title,
+		author:      doc.Info().Author,
+		nPages:      doc.GetNPages(),
+	}
+	return b, nil
+}
+
+func (d *browsableDoc) header() string {
+	return fmt.Sprintf("[yellow]%s - %s ~ Page %d of %d[-]",
+		d.title,
+		d.author,
+		d.currentPage+1,
+		d.nPages,
+	)
+}
+
+func (d *browsableDoc) status(accumulator int) string {
+
+	accumulated := ""
+	if accumulator != 0 {
+		accumulated = fmt.Sprintf("[%d] --", accumulator)
+	}
+
+	// TODO
+	// return fmt.Sprintf("%s %d", accumulated, percetuale_cursore)
+	return fmt.Sprintf("%s page %d of %d",
+		accumulated,
+		d.currentPage+1,
+		d.nPages,
+	)
+
+}
+
+func (d *browsableDoc) getCurrentPageText() string {
+	text, _ := d.doc.GetPageText(d.currentPage)
+	return text
+}
+
+type Browser struct {
+	app         *tview.Application
+	pageContent *tview.TextView
+	header      *tview.TextView
+	status      *tview.TextView
+	layout      *tview.Flex
+
+	docs    []*browsableDoc
+	currDoc int
+
+	accumulator int
+}
+
+func newBrowser(paths []string) *Browser {
+	app := tview.NewApplication()
+	header := tview.NewTextView().
+		SetDynamicColors(true).
+		SetRegions(true).
+		SetWordWrap(true).
+		SetChangedFunc(func() {
+			app.Draw()
+		})
+	pageContent := tview.NewTextView().
+		SetDynamicColors(true).
+		SetRegions(true).
+		SetWordWrap(true).
+		SetChangedFunc(func() {
+			app.Draw()
+		})
+	status := tview.NewTextView().
+		SetDynamicColors(true).
+		SetRegions(true).
+		SetWordWrap(true).
+		SetChangedFunc(func() {
+			app.Draw()
+		})
+	layout := tview.NewFlex().SetDirection(tview.FlexRow).
+		AddItem(header, 1, 0, false).     // TODO Fixed size header (1 line)
+		AddItem(pageContent, 0, 1, true). // TODO Content takes all remaining space
+		AddItem(status, 1, 0, false)      // TODO Fixed size footer (1 line)
+
+	var docs []*browsableDoc
+	for _, path := range paths {
+		doc, err := openBrowsableDoc(path)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "%s", err)
+		}
+		docs = append(docs, doc)
+	}
+
+	return &Browser{
+		app:         app,
+		header:      header,
+		pageContent: pageContent,
+		status:      status,
+		layout:      layout,
+		docs:        docs,
+	}
+
+}
+
+func (b *Browser) currentDoc() *browsableDoc {
+	return b.docs[b.currDoc]
+}
+
+func (b *Browser) updateStatus() {
+	b.status.SetText(b.currentDoc().status(b.accumulator))
+}
+
+func (b *Browser) updateHeader() {
+	b.header.SetText(b.currentDoc().header())
+}
+
+func (b *Browser) updateContent() {
+	text := b.currentDoc().getCurrentPageText()
+
+	b.pageContent.
+		SetTextAlign(tview.AlignLeft).
+		SetText(text).
+		SetBorder(true)
+}
+
+func (b *Browser) updatePage(newPage int) {
+	// lock mutex here
+	b.currentDoc().setCurrentPage(newPage)
+	b.updateHeader()
+	b.updateContent()
+	// unlock mutex here
+
+	b.updateStatus()
+}
+func (b *Browser) Run() {
+	b.updatePage(0)
+	b.app.SetInputCapture(b.handle)
+	if err := b.app.SetRoot(b.layout, true).Run(); err != nil {
+		panic(err)
+	}
+}
+
+// if acc is equal to 0 return 1, return acc otherwise
+func newAcc(acc int) int {
+	if acc == 0 {
+		return 1
+	}
+	return acc
+}
+
+func (b *Browser) nextDoc(acc int) {
+	acc = newAcc(acc)
+	// todo implement
+
+}
+func (b *Browser) prevDoc(acc int) {
+	acc = newAcc(acc)
+	// todo implement
+
+}
+func (b *Browser) nextPage(acc int) {
+	b.resetAccumulator()
+	acc = newAcc(acc)
+	currentPage := b.currentDoc().getCurrentPage()
+	b.updatePage(currentPage + acc)
+}
+func (b *Browser) prevPage(acc int) {
+	b.resetAccumulator()
+	acc = newAcc(acc)
+	currentPage := b.currentDoc().getCurrentPage()
+	b.updatePage(currentPage - acc)
+
+}
+func (b *Browser) scrollUp(acc int) {
+	b.resetAccumulator()
+	acc = newAcc(acc)
+	b.pageContent.ScrollTo(acc, 0)
+	b.updateStatus()
+
+}
+func (b *Browser) scrollDown(acc int) {
+	b.resetAccumulator()
+	acc = newAcc(acc)
+	b.pageContent.ScrollTo(acc, 0)
+	b.updateStatus()
+}
+
+func (b *Browser) resetAccumulator() {
+	b.accumulator = 0
+}
+func (b *Browser) handle(event *tcell.EventKey) *tcell.EventKey {
+	switch event.Key() {
+	case tcell.KeyEscape:
+		b.accumulator = 0
+		b.updateStatus()
+	case tcell.KeyRune:
+		switch event.Rune() {
+		case 'Q':
+			b.app.Stop()
+			return event
+			//TODO		case 'q': QUIT CURRENT DOCUMENT
+			//			b.app.Stop()
+			//			return event
+		case 'N':
+			b.nextDoc(b.accumulator)
+		case 'P':
+			b.prevDoc(b.accumulator)
+		case 'n':
+			b.nextPage(b.accumulator)
+		case 'p':
+			b.prevPage(b.accumulator)
+		case 'j':
+			b.scrollUp(b.accumulator)
+		case 'k':
+			b.scrollDown(b.accumulator)
+		default:
+			if event.Rune() >= '0' && event.Rune() <= '9' {
+				b.accumulator = b.accumulator*10 + int(event.Rune()-'0')
+				b.updateStatus()
+			}
+		}
+	}
+	return event
+}
+
+// browseCmd represents the browse command
+var browseCmd = &cobra.Command{
+	Use:   "browse",
+	Short: "browse pdf file",
+	Long: `A longer description that spans multiple lines and likely contains examples
+and usage of using your command. For example:
+
+Cobra is a CLI library for Go that empowers applications.
+This application is a tool to generate the needed files
+to quickly create a Cobra application.`,
+	Run: func(cmd *cobra.Command, args []string) {
+
+		var docs []*document.GhlighDoc
+		for _, arg := range args {
+			doc, err := document.Open(arg)
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "could not open %s: %v\n", arg, err)
+				continue
+			}
+			docs = append(docs, doc)
+		}
+
+		// if more then one file show menu
+		browser := newBrowser(args)
+		browser.Run()
+
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(browseCmd)
+
+	// Here you will define your flags and configuration settings.
+
+	// Cobra supports Persistent Flags which will work for this command
+	// and all subcommands, e.g.:
+	// browseCmd.PersistentFlags().String("foo", "", "A help for foo")
+
+	// Cobra supports local flags which will only run when this command
+	// is called directly, e.g.:
+	// browseCmd.Flags().BoolP("toggle", "t", false, "Help message for toggle")
+}
diff --git a/document/document.go b/document/document.go
index a036eee..cd84875 100644
--- a/document/document.go
+++ b/document/document.go
@@ -134,6 +134,24 @@ func integrityCheck(tizio *GhlighDoc, caio *GhlighDoc) {
 
 }
 
+func (d *GhlighDoc) GetNPages() int {
+	return d.doc.GetNPages()
+}
+
+func (d *GhlighDoc) GetPageText(i int) (string, error) {
+	nPages := d.doc.GetNPages()
+
+	if i < 0 || i > nPages {
+		return "", fmt.Errorf("error page %d out of range %d", i, nPages)
+	}
+
+	p := d.doc.GetPage(i)
+	defer p.Close()
+
+	text := p.Text()
+	return text, nil
+}
+
 func (d *GhlighDoc) Save() (bool, error) {
 	d.mu.Lock()
 	defer d.mu.Unlock()
diff --git a/go-poppler/page.go b/go-poppler/page.go
index efd0706..ffb408c 100644
--- a/go-poppler/page.go
+++ b/go-poppler/page.go
@@ -5,13 +5,16 @@ package poppler
 // #include <glib.h>
 // #include <cairo.h>
 import "C"
-import "unsafe"
-import "github.com/ungerik/go-cairo"
+import (
+	"unsafe"
+
+	"github.com/ungerik/go-cairo"
+)
 
 //import "fmt"
 
 type Page struct {
-	p *C.struct__PopplerPage
+	p            *C.struct__PopplerPage
 	openedAnnots []*Annot
 }
 
@@ -145,28 +148,28 @@ func (p *Page) Close() {
 
 // Converts a page into SVG and saves to file.
 // Inspired by https://github.com/dawbarton/pdf2svg
-func (p *Page) ConvertToSVG(filename string){
+func (p *Page) ConvertToSVG(filename string) {
 	width, height := p.Size()
 
 	// Open the SVG file
-	surface := cairo.NewSVGSurface( filename, width, height, cairo.SVG_VERSION_1_2 )
+	surface := cairo.NewSVGSurface(filename, width, height, cairo.SVG_VERSION_1_2)
 
 	// TODO Can be improved by using cairo_svg_surface_create_for_stream() instead of
 	//      cairo_svg_surface_create() for stream processing instead of file processing.
 	//      However, this needs to be changed in github.com/ungerik/go-cairo/surface.go
 
 	// Get cairo context pointer
-	_, drawcontext :=  surface.Native()
+	_, drawcontext := surface.Native()
 
 	// Render the PDF file into the SVG file
-	C.poppler_page_render_for_printing(p.p, (*C.cairo_t)(unsafe.Pointer(drawcontext)) );
+	C.poppler_page_render_for_printing(p.p, (*C.cairo_t)(unsafe.Pointer(drawcontext)))
 
 	// Close the SVG file
 	surface.ShowPage()
 	surface.Destroy()
 }
 
-func (p *Page) closeAnnotMappings(){
+func (p *Page) closeAnnotMappings() {
 	for i := 0; i < len(p.openedAnnots); i++ {
 		p.openedAnnots[i].Close()
 	}
@@ -186,7 +189,6 @@ func (p *Page) GetAnnots() (Annots []*Annot) {
 	for annotGlist != nil {
 		popplerAnnot := (*C.PopplerAnnotMapping)(annotGlist.data)
 
-
 		annot := &Annot{
 			am: popplerAnnot,
 		}
@@ -197,7 +199,6 @@ func (p *Page) GetAnnots() (Annots []*Annot) {
 		annots = append(annots, annot)
 		p.openedAnnots = append(p.openedAnnots, annot)
 
-
 		annotGlist = annotGlist.next
 	}