' main.bas
#inclib "gtk-3"

#define __USE_GTK3__
#include once "gtk/gtk.bi"

#include once "doc.bi"

' ---------- Globals ----------
dim shared gWin      as GtkWidget ptr
dim shared gView     as GtkWidget ptr
dim shared gBuf      as GtkTextBuffer ptr
dim shared gStatus   as GtkWidget ptr
dim shared gStatusId as guint
dim shared gDoc      as DocState

const APP_NAME    = "FREEnote"
const APP_VERSION = "0.1"

' ---------- Helpers ----------
function AppTitle() as string
    dim appBase as string = APP_NAME
    dim docLabel as string

    if gDoc.path <> "" then
        docLabel = gDoc.path
    else
        docLabel = "Untitled"
    end if

    if gDoc.modified <> 0 then
        return appBase & " - " & docLabel & " *"
    else
        return appBase & " - " & docLabel
    end if
end function

declare function OnDeleteEvent cdecl (byval widget as GtkWidget ptr, byval event as GdkEvent ptr, byval userData as gpointer) as gboolean
declare function SaveCurrent() as integer

sub UpdateTitle()
    gtk_window_set_title(GTK_WINDOW(gWin), AppTitle())
end sub

sub UpdateStatus()
    ' Line/Col from insert mark
    dim insMark as GtkTextMark ptr = gtk_text_buffer_get_insert(gBuf)
    dim it as GtkTextIter
    gtk_text_buffer_get_iter_at_mark(gBuf, @it, insMark)

    dim ln as integer = gtk_text_iter_get_line(@it) + 1
    dim col as integer = gtk_text_iter_get_line_offset(@it) + 1

    dim msg as string = "Ln " & str(ln) & ", Col " & str(col) & _
                        iif(gDoc.modified<>0, "   (Modified)", "   (Saved)")

    gtk_statusbar_pop(GTK_STATUSBAR(gStatus), gStatusId)
    gtk_statusbar_push(GTK_STATUSBAR(gStatus), gStatusId, msg)
end sub

sub SetBufferText(byref s as string)
    gtk_text_buffer_set_text(gBuf, s, len(s))
    ' Clear modified flag after programmatic set
    gtk_text_buffer_set_modified(gBuf, FALSE)
    Doc_SetModified(gDoc, 0)
    UpdateTitle()
    UpdateStatus()
end sub

function GetBufferText() as string
    dim a as GtkTextIter, b as GtkTextIter
    gtk_text_buffer_get_bounds(gBuf, @a, @b)

    dim p as zstring ptr = gtk_text_buffer_get_text(gBuf, @a, @b, TRUE)
    dim textOut as string = *p
    g_free(p)

    return textOut
end function

' returns: 0 cancel, 1 discard, 2 save
function ConfirmDiscardChanges() as integer
    if gDoc.modified = 0 then return 1

    dim dlg as GtkWidget ptr
    dlg = gtk_message_dialog_new( _
        GTK_WINDOW(gWin), _
        GTK_DIALOG_MODAL, _
        GTK_MESSAGE_WARNING, _
        GTK_BUTTONS_NONE, _
        "This document has unsaved changes." _
    )

    gtk_dialog_add_button(GTK_DIALOG(dlg), "Cancel", GTK_RESPONSE_CANCEL)
    gtk_dialog_add_button(GTK_DIALOG(dlg), "Discard", GTK_RESPONSE_REJECT)
    gtk_dialog_add_button(GTK_DIALOG(dlg), "Save", GTK_RESPONSE_ACCEPT)

    gtk_message_dialog_format_secondary_text( _
        GTK_MESSAGE_DIALOG(dlg), _
        "Do you want to save your changes before continuing?" _
    )

    dim resp as integer = gtk_dialog_run(GTK_DIALOG(dlg))
    gtk_widget_destroy(dlg)

    select case resp
    case GTK_RESPONSE_ACCEPT
        return 2
    case GTK_RESPONSE_REJECT
        return 1
    case else
        return 0
    end select
end function

function WriteFile(byref path as string, byref contents as string) as integer
    dim f as integer = freefile()
    if open(path for output as #f) <> 0 then return 0
    print #f, contents;
    close #f
    return 1
end function

function ReadFile(byref path as string, byref outText as string) as integer
    dim f as integer = freefile()
    if open(path for input as #f) <> 0 then return 0

    outText = ""
    while not eof(f)
        dim oneLine as string
        line input #f, oneLine
        if outText <> "" then outText &= chr(10)
        outText &= oneLine
    wend

    close #f
    return 1
end function

function OnDeleteEvent cdecl (byval widget as GtkWidget ptr, byval event as GdkEvent ptr, byval userData as gpointer) as gboolean
    dim r as integer = ConfirmDiscardChanges()
    if r = 0 then return TRUE

    if r = 2 then
        if SaveCurrent() = 0 then return TRUE
    end if

    return FALSE
end function

function ChooseOpenPath() as string
    dim dlg as GtkWidget ptr
    dlg = gtk_file_chooser_dialog_new( _
        "Open File", _
        GTK_WINDOW(gWin), _
        GTK_FILE_CHOOSER_ACTION_OPEN, _
        "_Cancel", GTK_RESPONSE_CANCEL, _
        "_Open", GTK_RESPONSE_ACCEPT, _
        NULL _
    )

    dim result as string = ""
    if gtk_dialog_run(GTK_DIALOG(dlg)) = GTK_RESPONSE_ACCEPT then
        dim p as zstring ptr = gtk_file_chooser_get_filename(GTK_FILE_CHOOSER(dlg))
        if p <> 0 then
            result = *p
            g_free(p)
        end if
    end if
    gtk_widget_destroy(dlg)
    return result
end function

function ChooseSavePath(byref suggested as string) as string
    dim dlg as GtkWidget ptr
    dlg = gtk_file_chooser_dialog_new( _
        "Save File", _
        GTK_WINDOW(gWin), _
        GTK_FILE_CHOOSER_ACTION_SAVE, _
        "_Cancel", GTK_RESPONSE_CANCEL, _
        "_Save", GTK_RESPONSE_ACCEPT, _
        NULL _
    )

    gtk_file_chooser_set_do_overwrite_confirmation(GTK_FILE_CHOOSER(dlg), TRUE)

    if suggested <> "" then
        gtk_file_chooser_set_filename(GTK_FILE_CHOOSER(dlg), suggested)
    end if

    dim result as string = ""
    if gtk_dialog_run(GTK_DIALOG(dlg)) = GTK_RESPONSE_ACCEPT then
        dim p as zstring ptr = gtk_file_chooser_get_filename(GTK_FILE_CHOOSER(dlg))
        if p <> 0 then
            result = *p
            g_free(p)
        end if
    end if
    gtk_widget_destroy(dlg)
    return result
end function

function SaveToPath(byref path as string) as integer
    dim txt as string = GetBufferText()
    if WriteFile(path, txt) = 0 then
        dim errDlg as GtkWidget ptr
        errDlg = gtk_message_dialog_new( _
            GTK_WINDOW(gWin), GTK_DIALOG_MODAL, _
            GTK_MESSAGE_ERROR, GTK_BUTTONS_OK, _
            "Could not save file." _
        )
        gtk_message_dialog_format_secondary_text(GTK_MESSAGE_DIALOG(errDlg), path)
        gtk_dialog_run(GTK_DIALOG(errDlg))
        gtk_widget_destroy(errDlg)
        return 0
    end if

    Doc_SetPath(gDoc, path)
    gtk_text_buffer_set_modified(gBuf, FALSE)
    Doc_SetModified(gDoc, 0)
    UpdateTitle()
    UpdateStatus()
    return 1
end function

function SaveCurrent() as integer
    if gDoc.path = "" then
        dim chosen as string = ChooseSavePath("")
        if chosen = "" then return 0
        return SaveToPath(chosen)
    else
        return SaveToPath(gDoc.path)
    end if
end function

' ---------- Callbacks ----------
sub OnBufferModifiedChanged cdecl (byval buf as GtkTextBuffer ptr, byval userData as gpointer)
    dim m as gboolean = gtk_text_buffer_get_modified(buf)
    Doc_SetModified(gDoc, iif(m, 1, 0))
    UpdateTitle()
    UpdateStatus()
end sub

sub OnMarkSet cdecl (byval buf as GtkTextBuffer ptr, byval iter as GtkTextIter ptr, byval mark as GtkTextMark ptr, byval userData as gpointer)
    UpdateStatus()
end sub

sub OnNew cdecl (byval widget as GtkWidget ptr, byval userData as gpointer)
    dim r as integer = ConfirmDiscardChanges()
    if r = 0 then exit sub
    if r = 2 then
        if SaveCurrent() = 0 then exit sub
    end if

    Doc_SetPath(gDoc, "")
    SetBufferText("")
end sub

sub OnOpen cdecl (byval widget as GtkWidget ptr, byval userData as gpointer)
    dim r as integer = ConfirmDiscardChanges()
    if r = 0 then exit sub
    if r = 2 then
        if SaveCurrent() = 0 then exit sub
    end if

    dim path as string = ChooseOpenPath()
    if path = "" then exit sub

    dim txt as string
    if ReadFile(path, txt) = 0 then
        dim errDlg as GtkWidget ptr
        errDlg = gtk_message_dialog_new( _
            GTK_WINDOW(gWin), GTK_DIALOG_MODAL, _
            GTK_MESSAGE_ERROR, GTK_BUTTONS_OK, _
            "Could not open file." _
        )
        gtk_message_dialog_format_secondary_text(GTK_MESSAGE_DIALOG(errDlg), path)
        gtk_dialog_run(GTK_DIALOG(errDlg))
        gtk_widget_destroy(errDlg)
        exit sub
    end if

    Doc_SetPath(gDoc, path)
    SetBufferText(txt)
end sub

sub OnSave cdecl (byval widget as GtkWidget ptr, byval userData as gpointer)
    SaveCurrent()
end sub

sub OnSaveAs cdecl (byval widget as GtkWidget ptr, byval userData as gpointer)
    dim suggested as string = gDoc.path
    dim chosen as string = ChooseSavePath(suggested)
    if chosen = "" then exit sub
    SaveToPath(chosen)
end sub

sub OnExit cdecl (byval widget as GtkWidget ptr, byval userData as gpointer)
    gtk_widget_destroy(gWin)
end sub

sub OnAbout cdecl (byval widget as GtkWidget ptr, byval userData as gpointer)
    dim dlg as GtkWidget ptr
    dlg = gtk_message_dialog_new( _
        GTK_WINDOW(gWin), _
        GTK_DIALOG_MODAL, _
        GTK_MESSAGE_INFO, _
        GTK_BUTTONS_OK, _
        APP_NAME & " " & APP_VERSION _
    )

    gtk_message_dialog_format_secondary_text( _
        GTK_MESSAGE_DIALOG(dlg), _
        "A lightweight text editor written in FreeBASIC + GTK3." & chr(10) & _
        "Created by John Paul Wohlscheid and ChatGPT." _
    )

    gtk_dialog_run(GTK_DIALOG(dlg))
    gtk_widget_destroy(dlg)
end sub

' ---------- UI Construction ----------
function MakeMenuBar() as GtkWidget ptr
    dim menubar as GtkWidget ptr = gtk_menu_bar_new()

    ' File menu
    dim fileItem as GtkWidget ptr = gtk_menu_item_new_with_label("File")
    dim fileMenu as GtkWidget ptr = gtk_menu_new()

    dim miNew   as GtkWidget ptr = gtk_menu_item_new_with_label("New")
    dim miOpen  as GtkWidget ptr = gtk_menu_item_new_with_label("Open")
    dim miSave  as GtkWidget ptr = gtk_menu_item_new_with_label("Save")
    dim miSaveA as GtkWidget ptr = gtk_menu_item_new_with_label("Save As")
    dim sep1    as GtkWidget ptr = gtk_separator_menu_item_new()
    dim miExit  as GtkWidget ptr = gtk_menu_item_new_with_label("Exit")

    gtk_menu_shell_append(GTK_MENU_SHELL(fileMenu), miNew)
    gtk_menu_shell_append(GTK_MENU_SHELL(fileMenu), miOpen)
    gtk_menu_shell_append(GTK_MENU_SHELL(fileMenu), miSave)
    gtk_menu_shell_append(GTK_MENU_SHELL(fileMenu), miSaveA)
    gtk_menu_shell_append(GTK_MENU_SHELL(fileMenu), sep1)
    gtk_menu_shell_append(GTK_MENU_SHELL(fileMenu), miExit)

    gtk_menu_item_set_submenu(GTK_MENU_ITEM(fileItem), fileMenu)
    gtk_menu_shell_append(GTK_MENU_SHELL(menubar), fileItem)

    g_signal_connect(miNew,  "activate", G_CALLBACK(@OnNew),   NULL)
    g_signal_connect(miOpen, "activate", G_CALLBACK(@OnOpen),  NULL)
    g_signal_connect(miSave, "activate", G_CALLBACK(@OnSave),  NULL)
    g_signal_connect(miSaveA,"activate", G_CALLBACK(@OnSaveAs),NULL)
    g_signal_connect(miExit, "activate", G_CALLBACK(@OnExit),  NULL)

    ' Help menu
    dim helpItem as GtkWidget ptr = gtk_menu_item_new_with_label("Help")
    dim helpMenu as GtkWidget ptr = gtk_menu_new()
    dim miAbout  as GtkWidget ptr = gtk_menu_item_new_with_label("About")

    gtk_menu_shell_append(GTK_MENU_SHELL(helpMenu), miAbout)
    gtk_menu_item_set_submenu(GTK_MENU_ITEM(helpItem), helpMenu)
    gtk_menu_shell_append(GTK_MENU_SHELL(menubar), helpItem)

    g_signal_connect(miAbout, "activate", G_CALLBACK(@OnAbout), NULL)

    return menubar
end function

' ---------- Main ----------
gtk_init(NULL, NULL)

Doc_Init(gDoc)

gWin = gtk_window_new(GTK_WINDOW_TOPLEVEL)
gtk_window_set_default_size(GTK_WINDOW(gWin), 900, 600)
UpdateTitle()

g_signal_connect(gWin, "delete-event", G_CALLBACK(@OnDeleteEvent), NULL)

dim vbox as GtkWidget ptr = gtk_box_new(GTK_ORIENTATION_VERTICAL, 0)
gtk_container_add(GTK_CONTAINER(gWin), vbox)

dim menubar as GtkWidget ptr = MakeMenuBar()
gtk_box_pack_start(GTK_BOX(vbox), menubar, FALSE, FALSE, 0)

' Scrolled editor
dim scroller as GtkWidget ptr = gtk_scrolled_window_new(NULL, NULL)
gtk_scrolled_window_set_policy(GTK_SCROLLED_WINDOW(scroller), GTK_POLICY_AUTOMATIC, GTK_POLICY_AUTOMATIC)
gtk_box_pack_start(GTK_BOX(vbox), scroller, TRUE, TRUE, 0)

gView = gtk_text_view_new()
gtk_container_add(GTK_CONTAINER(scroller), gView)

gBuf = gtk_text_view_get_buffer(GTK_TEXT_VIEW(gView))

' Statusbar
gStatus = gtk_statusbar_new()
gStatusId = gtk_statusbar_get_context_id(GTK_STATUSBAR(gStatus), "cursor")
gtk_box_pack_end(GTK_BOX(vbox), gStatus, FALSE, FALSE, 0)

' Buffer signals for modified + cursor status
g_signal_connect(gBuf, "modified-changed", G_CALLBACK(@OnBufferModifiedChanged), NULL)
g_signal_connect(gBuf, "mark-set",         G_CALLBACK(@OnMarkSet), NULL)

UpdateStatus()

gtk_widget_show_all(gWin)
gtk_main()