[gnumeric: 1/9] ssdiff: new utility to compare two spreadsheets.

[Morten Welinder <mortenw src gnome org>]

commit 77c4f4fb94c43fd347542cedb85996f434b5614e
Author: Morten Welinder <terra gnome org>
Date:   Sat Dec 15 11:36:19 2012 -0500

    ssdiff: new utility to compare two spreadsheets.
    
    This is a rough first cut.

 src/.gitignore  |    2 +
 src/Makefile.am |    5 +
 src/ssdiff.c    |  271 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 278 insertions(+), 0 deletions(-)
---
diff --git a/src/.gitignore b/src/.gitignore
index 5391b59..6053a1e 100644
--- a/src/.gitignore
+++ b/src/.gitignore
@@ -22,6 +22,8 @@ ssgrep
 ssgrep.exe
 sstest
 sstest.exe
+ssdiff
+ssdiff.exe
 test-pango
 test-pango.exe
 GNOME_Gnumeric-gtk.xml
diff --git a/src/Makefile.am b/src/Makefile.am
index d326b0f..5bd810c 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -37,6 +37,7 @@ endif
 if ENABLE_SSGREP
   bin_PROGRAMS += ssgrep
 endif
+bin_PROGRAMS += ssdiff
 
 AM_CPPFLAGS = 								\
 	-I$(top_srcdir)							\
@@ -363,6 +364,10 @@ sstest_LDADD   = $(gnumeric_LDADD)
 sstest_LDFLAGS = -export-dynamic
 sstest_SOURCES =				\
 	sstest.c
+ssdiff_LDADD   = $(gnumeric_LDADD)
+ssdiff_LDFLAGS = -export-dynamic
+ssdiff_SOURCES =				\
+	ssdiff.c
 
 test_pango_LDADD   = $(gnumeric_LDADD)
 test_pango_LDFLAGS = -export-dynamic
diff --git a/src/ssdiff.c b/src/ssdiff.c
new file mode 100644
index 0000000..54cad03
--- /dev/null
+++ b/src/ssdiff.c
@@ -0,0 +1,271 @@
+/*
+ * ssdiff.c: A diff program for spreadsheets.
+ *
+ * Author:
+ *   Morten Welinder <terra gnome org>
+ *
+ * Copyright (C) 2012 Morten Welinder (terra gnome org)
+ */
+
+#include <gnumeric-config.h>
+#include <glib/gi18n.h>
+#include "gnumeric.h"
+#include <goffice/goffice.h>
+#include "libgnumeric.h"
+#include "gutils.h"
+#include "command-context.h"
+#include "command-context-stderr.h"
+#include "gnm-plugin.h"
+#include "workbook-view.h"
+#include "workbook.h"
+#include "sheet.h"
+#include "cell.h"
+#include "value.h"
+
+static gboolean ssdiff_show_version = FALSE;
+
+static const GOptionEntry ssdiff_options [] = {
+	{
+		"version", 'v',
+		0, G_OPTION_ARG_NONE, &ssdiff_show_version,
+		N_("Display program version"),
+		NULL
+	},
+
+	/* ---------------------------------------- */
+
+	{ NULL }
+};
+
+typedef struct GnmDiffHandler_ {
+	GOIOContext *ioc;
+	struct {
+		char *url;
+		Workbook *wb;
+		WorkbookView *wbv;
+	} old, new;
+} GnmDiffHandler;
+
+static gint
+cell_ordering (gconstpointer a_, gconstpointer b_)
+{
+	GnmCell const *a = *(GnmCell **)a_;
+	GnmCell const *b = *(GnmCell **)b_;
+
+	if (a->pos.row != b->pos.row)
+		return a->pos.row - b->pos.row;
+
+	return a->pos.col - b->pos.col;
+}
+
+static gboolean
+compare_cells (GnmCell const *co, GnmCell const *cn)
+{
+	gboolean has_expr = gnm_cell_has_expr (co);
+	gboolean has_value = co->value != NULL;
+
+	if (has_expr != gnm_cell_has_expr (cn))
+		return TRUE;
+	if (has_expr) {
+		char *eo = gnm_cell_get_entered_text (co);
+		char *en = gnm_cell_get_entered_text (cn);
+		gboolean changed = !g_str_equal (co, cn);
+		g_free (eo);
+		g_free (en);
+		return changed;
+	}
+
+	if (has_value != (cn->value != NULL))
+		return TRUE;
+	if (has_value)
+		return !value_equal (co->value, cn->value);
+
+	return FALSE;
+}
+      
+
+static void
+diff_sheets_cells (GnmDiffHandler *state, Sheet *old_sheet, Sheet *new_sheet)
+{
+	GPtrArray *old_cells = sheet_cells (old_sheet, NULL);
+	GPtrArray *new_cells = sheet_cells (new_sheet, NULL);
+	size_t io = 0, in = 0;
+
+	/* Make code below simpler.  */
+	g_ptr_array_add (old_cells, NULL);
+	g_ptr_array_add (new_cells, NULL);
+
+	while (TRUE) {
+		GnmCell const *co = g_ptr_array_index (old_cells, io);
+		GnmCell const *cn = g_ptr_array_index (new_cells, in);
+
+		if (co && cn) {
+			int order = cell_ordering (&co, &cn);
+			if (order < 0)
+				cn = NULL;
+			else if (order > 0)
+				co = NULL;
+			else {
+				if (compare_cells (co, cn)) {
+					g_printerr ("Contents of %s!%s has changed.\n",
+						    old_sheet->name_quoted,
+						    cell_name (co));
+				}
+
+				io++, in++;
+				continue;
+			}			
+		}
+
+		if (co) {
+			g_printerr ("Cell %s!%s removed.\n",
+				    old_sheet->name_quoted, cell_name (co));
+			io++;
+		} else if (cn) {
+			g_printerr ("Cell %s!%s added.\n",
+				    new_sheet->name_quoted, cell_name (cn));
+			in++;
+		} else
+			break;
+	}
+
+	g_ptr_array_free (old_cells, TRUE);
+	g_ptr_array_free (new_cells, TRUE);
+}
+
+static void
+diff_sheets (GnmDiffHandler *state, Sheet *old_sheet, Sheet *new_sheet)
+{
+	/* Compare sheet attributes and sizes */
+
+	diff_sheets_cells (state, old_sheet, new_sheet);
+
+	/* Compare style */
+}
+
+static int
+diff (char const *oldfilename, char const *newfilename, GOIOContext *ioc)
+{
+	GnmDiffHandler state;
+	int res = 0;
+	int i, count;
+
+	memset (&state, 0, sizeof (state));
+	state.ioc = ioc;
+
+	state.old.url = go_shell_arg_to_uri (oldfilename);
+	state.new.url = go_shell_arg_to_uri (newfilename);
+
+	state.old.wbv = workbook_view_new_from_uri (state.old.url, NULL,
+						    ioc, NULL);
+	if (!state.old.wbv)
+		goto error;
+	state.old.wb = wb_view_get_workbook (state.old.wbv);
+
+	state.new.wbv = workbook_view_new_from_uri (state.new.url, NULL,
+						    ioc, NULL);
+	if (!state.new.wbv)
+		goto error;
+	state.new.wb = wb_view_get_workbook (state.new.wbv);
+
+	count = workbook_sheet_count (state.old.wb);
+	for (i = 0; i < count; i++) {
+		Sheet *old_sheet = workbook_sheet_by_index (state.old.wb, i);
+		Sheet *new_sheet = workbook_sheet_by_name (state.new.wb,
+							   old_sheet->name_unquoted);
+		if (new_sheet)
+			diff_sheets (&state, old_sheet, new_sheet);
+		else {
+			g_printerr ("Sheet %s removed.\n",
+				    old_sheet->name_quoted);
+		}
+	}
+
+	count = workbook_sheet_count (state.new.wb);
+	for (i = 0; i < count; i++) {
+		Sheet *new_sheet = workbook_sheet_by_index (state.new.wb, i);
+		Sheet *old_sheet = workbook_sheet_by_name (state.old.wb,
+							   new_sheet->name_unquoted);
+		if (old_sheet)
+			; /* Nothing */
+		else {
+			g_printerr ("Sheet %s added.\n",
+				    new_sheet->name_quoted);
+		}
+	}
+
+out:
+	g_free (state.old.url);
+	g_free (state.new.url);
+	if (state.old.wb)
+		g_object_unref (state.old.wb);
+	if (state.new.wb)
+		g_object_unref (state.new.wb);
+	return res;
+
+error:
+	res = 1;
+	goto out;
+}
+
+int
+main (int argc, char const **argv)
+{
+	GOErrorInfo	*plugin_errs;
+	int		 res = 0;
+	GOCmdContext	*cc;
+	GOptionContext *ocontext;
+	GError *error = NULL;
+
+	/* No code before here, we need to init threads */
+	argv = gnm_pre_parse_init (argc, argv);
+
+	ocontext = g_option_context_new (_("OLDFILE NEWFILE"));
+	g_option_context_add_main_entries (ocontext, ssdiff_options, GETTEXT_PACKAGE);
+	g_option_context_add_group	  (ocontext, gnm_get_option_group ());
+	g_option_context_parse (ocontext, &argc, (char ***)&argv, &error);
+	g_option_context_free (ocontext);
+
+	if (error) {
+		g_printerr (_("%s\nRun '%s --help' to see a full list of available command line options.\n"),
+			    error->message, argv[0]);
+		g_error_free (error);
+		return 1;
+	}
+
+	if (ssdiff_show_version) {
+		g_print (_("ssdiff version '%s'\ndatadir := '%s'\nlibdir := '%s'\n"),
+			 GNM_VERSION_FULL, gnm_sys_data_dir (), gnm_sys_lib_dir ());
+		return 0;
+	}
+
+	gnm_init ();
+
+	cc = cmd_context_stderr_new ();
+	gnm_plugins_init (GO_CMD_CONTEXT (cc));
+	go_plugin_db_activate_plugin_list (
+		go_plugins_get_available_plugins (), &plugin_errs);
+	if (plugin_errs) {
+		/* FIXME: What do we want to do here? */
+		go_error_info_free (plugin_errs);
+	}
+	go_component_set_default_command_context (cc);
+
+	if (argc == 3) {
+		GOIOContext *ioc = go_io_context_new (cc);
+		res = diff (argv[1], argv[2], ioc);
+		g_object_unref (ioc);
+	} else {
+		g_printerr (_("Usage: %s [OPTION...] %s\n"),
+			    g_get_prgname (),
+			    _("OLDFILE NEWFILE"));
+		res = 1;
+	}
+
+	go_component_set_default_command_context (NULL);
+	g_object_unref (cc);
+	gnm_shutdown ();
+	gnm_pre_parse_shutdown ();
+
+	return res;
+}