guile repl access to full api

- launch guile or python REPL
- optionally load datafile, RO (default) or RW
- exposes qof-session-save-quiet
- optionally runs "--script script.scm" before REPL

gnucash/gnucash-cli.cpp

@@ -33,13 +33,17 @@
 #include <glib/gi18n.h>
 #include <gnc-engine.h>
 #include <gnc-prefs.h>
+#include "gnc-session.h"
+#include "gnc-prefs-utils.h"
+#include "libguile.h"
 
 #include <boost/locale.hpp>
 #include <boost/optional.hpp>
 #ifdef __MINGW32__
 #include <boost/nowide/args.hpp>
 #endif
 #include <iostream>
+#include <filesystem>
 #include <gnc-quotes.hpp>
 
 namespace bl = boost::locale;
@@ -62,6 +66,11 @@ namespace Gnucash {
         boost::optional <std::string> m_namespace;
         bool m_verbose = false;
 
+        boost::optional <std::string> m_script;
+        boost::optional <std::string> m_language;
+        bool m_interactive;
+        bool m_open_readwrite;
+
         boost::optional <std::string> m_report_cmd;
         boost::optional <std::string> m_report_name;
         boost::optional <std::string> m_export_type;
@@ -107,6 +116,15 @@ Gnucash::GnucashCli::configure_program_options (void)
     m_opt_desc_display->add (quotes_options);
     m_opt_desc_all.add (quotes_options);
 
+    bpo::options_description cli_options(_("Scripting and Interactive Session Options"));
+    cli_options.add_options()
+        ("script,S", bpo::value (&m_script), "Script to run")
+        ("interactive,I", bpo::bool_switch (&m_interactive), "Interactive session after possibly running script")
+        ("language,L", bpo::value (&m_language), "Specify language for script or interactive session; guile (default) or python")
+        ("readwrite,W", bpo::bool_switch (&m_open_readwrite), "Open datafile read-write for script and/or interactive session");
+    m_opt_desc_display->add (cli_options);
+    m_opt_desc_all.add (cli_options);
+
     bpo::options_description report_options(_("Report Generation Options"));
     report_options.add_options()
     ("report,R", bpo::value (&m_report_cmd),
@@ -126,11 +144,117 @@ may be specified to describe some saved options.\n"
 
 }
 
+struct cli_struct
+{
+    boost::optional<std::string> script;
+    bool interactive;
+    bool verbose;
+};
+
+static void
+run_guile_cli (void *data, [[maybe_unused]] int argc, [[maybe_unused]] char **argv)
+{
+    auto args = static_cast<cli_struct*>(data);
+    scm_c_use_module ("system repl repl");
+    scm_c_use_module ("gnucash core-utils");
+    scm_c_use_module ("gnucash engine");
+    scm_c_use_module ("gnucash app-utils");
+    scm_c_use_module ("gnucash report");
+    scm_c_use_module ("ice-9 readline");
+    scm_c_eval_string ("(activate-readline)");
+    if (args->script)
+    {
+        if (args->verbose)
+            std::cout << "Running script from " << *args->script << "...";
+        scm_c_primitive_load (args->script->c_str());
+        if (args->verbose)
+            std::cout << "success!" << std::endl;
+    }
+    if (args->interactive)
+    {
+        if (args->verbose)
+            std::cout << "Starting CLI... " << std::endl;
+        scm_c_eval_string ("(start-repl)");
+    }
+    if (gnc_current_session_exist())
+    {
+        if (args->verbose)
+            std::cout << "Warning: session still open. Clearing session..." << std::endl;
+        gnc_clear_current_session ();
+    }
+}
+
+static void load_file (std::string m_file_to_load, bool m_open_readwrite, bool m_verbose)
+{
+    if (m_verbose)
+        std::cout << "\n\nLoading " << m_file_to_load
+                  << (m_open_readwrite ? " (r/w)" : " (readonly)");
+    auto session = gnc_get_current_session();
+    auto mode = m_open_readwrite ? SESSION_READ_ONLY : SESSION_NORMAL_OPEN;
+    while (true)
+    {
+        qof_session_begin (session, m_file_to_load.c_str(), mode);
+        auto io_err = qof_session_get_error (session);
+        switch (io_err)
+        {
+        case ERR_BACKEND_NO_ERR:
+            qof_session_load (session, NULL);
+            if (m_verbose)
+                std::cout << "... done!\n\n";
+            return;
+        case ERR_BACKEND_LOCKED:
+        case ERR_BACKEND_READONLY:
+            if (m_verbose)
+                std::cout << " (forced readonly)";
+            mode = SESSION_READ_ONLY;
+            break;
+        default:
+            if (m_verbose)
+                std::cout << "... unknown error. Abort." << std::endl;
+            exit (1);
+        }
+    }
+}
+
 int
 Gnucash::GnucashCli::start ([[maybe_unused]] int argc, [[maybe_unused]] char **argv)
 {
     Gnucash::CoreApp::start();
 
+    if (m_interactive || m_script)
+    {
+        if (m_open_readwrite && !m_file_to_load)
+        {
+            std::cerr << "missing datafile to be open read/write!" << std::endl;
+            return 1;
+        }
+        if (m_script && (!std::filesystem::exists (*m_script) ||
+                         std::filesystem::is_directory (*m_script)))
+        {
+            std::cerr << "invalid script " << *m_script << std::endl;
+            return 1;
+        }
+        gnc_prefs_init ();
+        cli_struct args = { m_script, m_interactive, m_verbose };
+        if (!m_language || *m_language == "guile")
+        {
+            if (m_file_to_load)
+                load_file (*m_file_to_load, m_open_readwrite, m_verbose);
+            scm_boot_guile (0, nullptr, run_guile_cli, &args);
+            return 0;
+        }
+        else if (*m_language == "python")
+        {
+            std::cerr << "don't know how to launch python";
+            return 1;
+        }
+        else
+        {
+            std::cerr << "Valid languages are 'python' or 'guile'" << std::endl;
+            return 1;
+        }
+    }
+
     if (!m_quotes_cmd.empty())
     {
         if (m_quotes_cmd.front() == "info")