[gnucash-commands.cpp] scripting & REPL for guile & python

Syntax: gnucash-cli [datafile.gnucash [--readwrite]] [--interactive]
[--script script.py or script.scm] [--language python|guile]

1. --script or --interactive will launch scripting
2. a datafile will trigger loading, will attempt r/w if requested
3. --language python will choose python
4. --interactive will run the Guile or Python commandline with
access to gnucash modules

gnucash/CMakeLists.txt

@@ -111,6 +111,7 @@ target_link_libraries (gnucash
    gnc-bi-import gnc-customer-import gnc-report
    PkgConfig::GTK3 ${GUILE_LDFLAGS} PkgConfig::GLIB2
    ${Boost_LIBRARIES}
+   ${Python3_LIBRARIES}
 )
 
 set(gnucash_cli_SOURCES
@@ -137,15 +138,20 @@ endif()
 
 add_dependencies (gnucash-cli gnucash)
 
-target_compile_definitions(gnucash-cli PRIVATE -DG_LOG_DOMAIN=\"gnc.bin\")
+target_compile_definitions(gnucash-cli PRIVATE
+   -DG_LOG_DOMAIN=\"gnc.bin\"
+   $<$<BOOL:${WITH_PYTHON}>:HAVE_PYTHON_H>)
 
 target_link_libraries (gnucash-cli
    gnc-app-utils
    gnc-engine gnc-core-utils gnucash-guile gnc-report
    ${GUILE_LDFLAGS} PkgConfig::GLIB2
    ${Boost_LIBRARIES}
+   ${Python3_LIBRARIES}
 )
 
+target_include_directories (gnucash-cli PRIVATE ${Python3_INCLUDE_DIRS})
+
 if (BUILDING_FROM_VCS)
     target_compile_definitions(gnucash PRIVATE -DGNC_VCS=\"git\")
     target_compile_definitions(gnucash-cli PRIVATE -DGNC_VCS=\"git\")

gnucash/gnucash-cli.cpp

@@ -62,6 +62,12 @@ namespace Gnucash {
         boost::optional <std::string> m_namespace;
         bool m_verbose = false;
 
+        boost::optional <std::string> m_script;
+        std::vector<std::string> m_script_args;
+        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 +113,17 @@ 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/or Interactive Session Options"));
+    cli_options.add_options()
+        ("script,S", bpo::value (&m_script), _("Script to run"))
+        ("script-args", bpo::value (&m_script_args), _("Script arguments"))
+        ("interactive,I", bpo::bool_switch (&m_interactive), _("Interactive session"))
+        ("language,L", bpo::value (&m_language)->default_value("guile"), _("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_pos_opt_desc.add("script-args", -1);
+    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),
@@ -127,10 +144,32 @@ may be specified to describe some saved options.\n"
 }
 
 int
-Gnucash::GnucashCli::start ([[maybe_unused]] int argc, [[maybe_unused]] char **argv)
+Gnucash::GnucashCli::start (int argc, char **argv)
 {
     Gnucash::CoreApp::start();
 
+    if (m_interactive || m_script)
+    {
+        std::vector<const char*> newArgv =
+            { argc ? argv[0] : "", m_file_to_load ? m_file_to_load->c_str() : ""};
+        std::transform (m_script_args.begin(), m_script_args.end(), std::back_inserter(newArgv),
+                        [](const std::string& s) { return s.c_str(); });
+        // note the vector<const char*> is valid as long as script_args's strings are not damaged!
+
+        std::cout << "\n\nScript args:";
+        for (const auto& arg : newArgv)
+            std::cout << ' ' << arg;
+        std::cout << '\n';
+        std::cout << "File to load: " << (m_file_to_load ? *m_file_to_load : "(null)") << std::endl;
+        std::cout << "Language: " << m_language << std::endl;
+        std::cout << "Script: " << (m_script ? *m_script : "(null)") << std::endl;
+        std::cout << "Readwrite: " << (m_open_readwrite ? 'Y' : 'N') << std::endl;
+        std::cout << "Interactive: " << (m_interactive ? 'Y' : 'N') << "\n\n" << std::endl;
+
+        return Gnucash::run_scripting (newArgv, m_file_to_load, m_language, m_script,
+                                       m_open_readwrite, m_interactive);
+    }
+
     if (!m_quotes_cmd.empty())
     {
         if (m_quotes_cmd.front() == "info")

gnucash/gnucash-commands.cpp

@@ -31,6 +31,8 @@
 
 #include "gnucash-commands.hpp"
 #include "gnucash-core-app.hpp"
+#include "gnc-ui-util.h"
+#include "gnc-path.h"
 
 #include <gnc-filepath-utils.h>
 #include <gnc-engine-guile.h>
@@ -40,12 +42,17 @@
 #include <qoflog.h>
 
 #include <boost/locale.hpp>
+#include <boost/filesystem.hpp>
 #include <fstream>
 #include <iostream>
 #include <iomanip>
 #include <gnc-report.h>
 #include <gnc-quotes.hpp>
 
+#ifdef HAVE_PYTHON_H
+#include <Python.h>
+#endif
+
 namespace bl = boost::locale;
 
 static std::string empty_string{};
@@ -112,12 +119,48 @@ get_line (const char* prompt)
 static std::string
 get_choice (const char* prompt, const std::vector<std::string> choices)
 {
-    while (true)
+    std::string response;
+    do
     {
-        auto response = get_line (prompt);
-        if (std::find (choices.begin(), choices.end(), response) != choices.end())
-            return response;
+        response = get_line (prompt);
     }
+    while (std::none_of (choices.begin(), choices.end(),
+                         [&response](auto& choice) { return choice == response; } ));
+    return response;
+}
+
+struct scripting_args
+{
+    const boost::optional<std::string>& script;
+    bool interactive;
+};
+
+// when guile or python script/interactive session succeed
+static void
+cleanup_and_exit_with_save ()
+{
+    if (gnc_current_session_exist())
+    {
+        auto session = gnc_get_current_session();
+        auto book = gnc_get_current_book();
+        auto is_yes = [] (const char* prompt)
+        {
+            auto s = get_choice (prompt, {"Y","y","N","n"});
+            return s == "Y" || s == "y";
+        };
+
+        std::cerr << _("Warning: session was not cleared.") << std::endl;
+
+        if (!qof_book_session_not_saved (book))
+            std::cerr << _("Please don't forget to clear session before shutdown.") << std::endl;
+        else if (qof_book_is_readonly (book))
+            std::cerr << _("Book is readonly. Unsaved changes will be lost.") << std::endl;
+        else if (is_yes (_("There are unsaved changes. Save before clearing [YN]?")))
+            qof_session_save (session, report_session_percentage);
+
+        gnc_clear_current_session ();
+    }
+    gnc_shutdown_cli (0);
 }
 
 /* Don't try to use std::string& for the members of the following struct, it
@@ -469,3 +512,147 @@ Gnucash::report_list (void)
     scm_boot_guile (0, nullptr, scm_report_list, NULL);
     return 0;
 }
+
+// scripting code follows:
+
+static void
+run_guile_cli (void *data, [[maybe_unused]] int argc, [[maybe_unused]] char **argv)
+{
+    auto args = static_cast<scripting_args*>(data);
+    if (args->script)
+    {
+        PINFO ("Running script from %s... ", args->script->c_str());
+        scm_c_primitive_load (args->script->c_str());
+    }
+    if (args->interactive)
+    {
+        std::cout << _("Welcome to Gnucash Interactive Guile Session") << std::endl;
+        std::vector<const char*> modules =
+            { "gnucash core-utils", "gnucash engine", "gnucash app-utils", "gnucash report",
+              "system repl repl", "ice-9 readline" };
+        auto show_and_load = [](const auto& mod)
+        {
+            std::cout << bl::format ("(use-modules ({1}))") % mod << std::endl;
+            scm_c_use_module (mod);
+        };
+        std::for_each (modules.begin(), modules.end(), show_and_load);
+        scm_c_eval_string ("(activate-readline)");
+        scm_c_eval_string ("(start-repl)");
+    }
+    cleanup_and_exit_with_save ();
+}
+
+
+#ifdef HAVE_PYTHON_H
+static void
+python_cleanup_and_exit (PyConfig& config, PyStatus& status)
+{
+    if (qof_book_session_not_saved (gnc_get_current_book()))
+        std::cerr << _("Book is readonly. Unsaved changes will be lost.") << std::endl;
+    gnc_clear_current_session ();
+
+    PyConfig_Clear(&config);
+    if (status.err_msg && *status.err_msg)
+        std::cerr << bl::format (_("Python Config failed with error {1}")) % status.err_msg
+                  << std::endl;
+    gnc_shutdown_cli (status.exitcode);
+}
+
+static void
+run_python_cli (int argc, char **argv, scripting_args* args)
+{
+    PyConfig config;
+    PyConfig_InitPythonConfig(&config);
+
+    PyStatus status = PyConfig_SetBytesArgv(&config, argc, argv);
+    if (PyStatus_Exception(status))
+        python_cleanup_and_exit (config, status);
+
+    status = Py_InitializeFromConfig(&config);
+    if (PyStatus_Exception(status))
+        python_cleanup_and_exit (config, status);
+
+    PyConfig_Clear(&config);
+
+    if (args->script)
+    {
+        auto script_filename = args->script->c_str();
+        PINFO ("Running python script %s...", script_filename);
+        auto fp = fopen (script_filename, "rb");
+        if (!fp)
+        {
+            std::cerr << bl::format (_("Unable to load Python script {1}")) % script_filename
+                      << std::endl;
+            python_cleanup_and_exit (config, status);
+        }
+        else if (PyRun_SimpleFileEx (fp, script_filename, 1) != 0)
+        {
+            std::cerr << bl::format (_("Python script {1} execution failed.")) % script_filename
+                      << std::endl;
+            python_cleanup_and_exit (config, status);
+        }
+    }
+    if (args->interactive)
+    {
+        std::cout << _("Welcome to Gnucash Interactive Python Session") << std::endl;
+        PyRun_InteractiveLoop (stdin, "foo");
+    }
+    Py_Finalize();
+    cleanup_and_exit_with_save ();
+}
+#endif
+
+int
+Gnucash::run_scripting (std::vector<const char*> newArgv,
+                        const bo_str& file_to_load,
+                        std::string& language,
+                        const bo_str& script,
+                        bool open_readwrite,
+                        bool interactive)
+{
+    std::vector<std::string> errors;
+    static const std::vector<std::string> languages = { "guile", "python" };
+
+    if (open_readwrite && !file_to_load)
+        errors.push_back (_ ("--readwrite: missing datafile!"));
+
+    if (script && (!boost::filesystem::is_regular_file (*script)))
+        errors.push_back ((bl::format (_("--script: {1} is not a file")) % *script).str());
+
+    if (std::none_of (languages.begin(), languages.end(),
+                      [&language](auto& lang){ return language == lang; }))
+        errors.push_back (_ ("--language: must be 'python' or 'guile'"));
+#ifndef HAVE_PYTHON_H
+    else if (language == "python")
+        errors.push_back (_("--language: python wasn't compiled in this build"));
+#endif
+
+    if (!errors.empty())
+    {
+        std::cerr << _("Errors parsing arguments:") << std::endl;
+        auto to_console = [](const auto& str){ std::cerr << str << std::endl; };
+        std::for_each (errors.begin(), errors.end(), to_console);
+        gnc_shutdown_cli (1);
+    }
+
+    gnc_prefs_init ();
+    gnc_ui_util_init();
+    if (file_to_load && boost::filesystem::is_regular_file (*file_to_load))
+        [[maybe_unused]] auto session = load_file (*file_to_load, open_readwrite);
+
+    scripting_args args { script, interactive };
+    if (language == "guile")
+    {
+        scm_boot_guile (newArgv.size(), (char**)newArgv.data(), run_guile_cli, &args);
+        return 0;               // never reached...
+    }
+#ifdef HAVE_PYTHON_H
+    else if (language == "python")
+    {
+        run_python_cli (newArgv.size(), (char**)newArgv.data(), &args);
+        return 0;               // never reached...
+    }
+#endif
+
+    return 0;                   // never reached
+}

gnucash/gnucash-commands.hpp

@@ -46,5 +46,11 @@ namespace Gnucash {
     int report_list (void);
     int report_show (const bo_str& file_to_load,
                      const bo_str& run_report);
+    int run_scripting (std::vector<const char*> newArgv,
+                       const bo_str& m_file_to_load,
+                       std::string& m_language,
+                       const bo_str& m_script,
+                       bool m_open_readwrite,
+                       bool m_interactive);
 }
 #endif

gnucash/gnucash-core-app.cpp

@@ -294,7 +294,7 @@ Gnucash::CoreApp::add_common_program_options (void)
         ("input-file", bpo::value (&m_file_to_load),
          _("[datafile]"));
 
-        m_pos_opt_desc.add("input-file", -1);
+        m_pos_opt_desc.add("input-file", 1);
 
         m_opt_desc_all.add (common_options);
         m_opt_desc_all.add (hidden_options);