/*
 * Copyright (c) 2003-2016, John Wiegley.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of New Artisans LLC nor the names of its
 *   contributors may be used to endorse or promote products derived from
 *   this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <system.hh>

#include "global.h"
#if HAVE_BOOST_PYTHON
#include "pyinterp.h"
#else
#include "session.h"
#endif
#include "item.h"
#include "journal.h"
#include "pool.h"

namespace ledger {

static bool args_only = false;
std::string       _init_file;

global_scope_t::global_scope_t(char ** envp)
{
  epoch = CURRENT_TIME();

#if HAVE_BOOST_PYTHON
  if (! python_session.get()) {
    python_session.reset(new ledger::python_interpreter_t);
    session_ptr = python_session;
  }
#else
  session_ptr.reset(new session_t);
#endif

  set_session_context(session_ptr.get());

  // Create the report object, which maintains state relating to each
  // command invocation.  Because we're running from main(), the
  // distinction between session and report doesn't really matter, but if
  // a GUI were calling into Ledger it would have one session object per
  // open document, with a separate report_t object for each report it
  // generated.
  report_stack.push_front(new report_t(*session_ptr));
  scope_t::default_scope = &report();
  scope_t::empty_scope   = &empty_scope;

  // Read the user's options, in the following order:
  //
  //  1. environment variables (LEDGER_<option>)
  //  2. initialization file (~/.ledgerrc)
  //  3. command-line (--option or -o)
  //
  // Before processing command-line options, we must notify the session object
  // that such options are beginning, since options like -f cause a complete
  // override of files found anywhere else.
  if (! args_only) {
    session().set_flush_on_next_data_file(true);
    read_environment_settings(envp);
    session().set_flush_on_next_data_file(true);
    read_init();
  } else {
    session().HANDLER(price_db_).off();
  }

  TRACE_CTOR(global_scope_t, "");
}

global_scope_t::~global_scope_t()
{
  TRACE_DTOR(global_scope_t);

  // If memory verification is being performed (which can be very slow),
  // clean up everything by closing the session and deleting the session
  // object, and then shutting down the memory tracing subsystem.
  // Otherwise, let it all leak because we're about to exit anyway.
  IF_VERIFY() set_session_context(NULL);

#if HAVE_BOOST_PYTHON
  python_session.reset();
#endif
}

void global_scope_t::parse_init(path init_file)
{
  TRACE_START(init, 1, "Read initialization file");

  parse_context_stack_t parsing_context;
  parsing_context.push(init_file);
  parsing_context.get_current().journal = session().journal.get();
  parsing_context.get_current().scope   = &report();

  if (session().journal->read(parsing_context) > 0 ||
      session().journal->auto_xacts.size() > 0 ||
      session().journal->period_xacts.size() > 0) {
    throw_(parse_error, _f("Transactions found in initialization file '%1%'")
	   % init_file);
  }

  TRACE_FINISH(init, 1);
}

void global_scope_t::read_init()
{
  // if specified on the command line init_file_ is filled in
  // global_scope_t::handle_debug_options.  If it was specified on the command line
  // fail if the file doesn't exist. If no init file was specified
  // on the command-line then try the default values, but don't fail if there
  // isn't one.
  path init_file;
  if (HANDLED(init_file_)) {
    init_file=HANDLER(init_file_).str();
    if (exists(init_file)) {
      parse_init(init_file);
    } else {
      throw_(parse_error, _f("Could not find specified init file %1%") % init_file);
    }
  } else {
    if (const char * home_var = std::getenv("HOME")) {
      init_file = (path(home_var) / ".ledgerrc");
      if (! exists(init_file)) {
        init_file = ("./.ledgerrc");
      }
    } else {
      init_file = ("./.ledgerrc");
    }
  }
  if (exists(init_file)) {
    parse_init(init_file);
  }
}


char * global_scope_t::prompt_string()
{
  static char prompt[32];
  std::size_t i;
  for (i = 0; i < report_stack.size(); i++)
    prompt[i] = ']';
  prompt[i++] = ' ';
  prompt[i]   = '\0';
  return prompt;
}

void global_scope_t::report_error(const std::exception& err)
{
  std::cout.flush();            // first display anything that was pending

  if (caught_signal == NONE_CAUGHT) {
    // Display any pending error context information
    string context = error_context();
    if (! context.empty())
      std::cerr << context << std::endl;

    std::cerr << _("Error: ") << err.what() << std::endl;
  } else {
    caught_signal = NONE_CAUGHT;
  }
}

void global_scope_t::execute_command(strings_list args, bool at_repl)
{
  session().set_flush_on_next_data_file(true);

  // Process the command verb, arguments and options
  if (at_repl) {
    args = read_command_arguments(report(), args);
    if (args.empty())
      return;
  }

  strings_list::iterator arg  = args.begin();
  string                 verb = *arg++;

  // Look for a precommand first, which is defined as any defined function
  // whose name starts with "ledger_precmd_".  The difference between a
  // precommand and a regular command is that precommands ignore the journal
  // data file completely, nor is the user's init file read.
  //
  // Here are some examples of pre-commands:
  //
  //   parse STRING       ; show how a value expression is parsed
  //   eval STRING        ; simply evaluate a value expression
  //   format STRING      ; show how a format string is parsed
  //
  // If such a command is found, create the output stream for the result and
  // then invoke the command.

  expr_t::func_t command;
  bool           is_precommand = false;
  bind_scope_t   bound_scope(*this, report());

  if (bool(command = look_for_precommand(bound_scope, verb)))
    is_precommand = true;

  // If it is not a pre-command, then parse the user's ledger data at this
  // time if not done already (i.e., if not at a REPL).  Then patch up the
  // report options based on the command verb.

  if (! is_precommand) {
    if (! at_repl)
      session().read_journal_files();

    report().normalize_options(verb);

    if (! bool(command = look_for_command(bound_scope, verb)))
      throw_(std::logic_error, _f("Unrecognized command '%1%'") % verb);
  }

  // Create the output stream (it might be a file, the console or a PAGER
  // subprocess) and invoke the report command.  The output stream is closed
  // by the caller of this function.

  report().output_stream
    .initialize(report().HANDLED(output_) ?
                optional<path>(path(report().HANDLER(output_).str())) :
                optional<path>(),
                report().HANDLED(pager_) ?
                optional<path>(path(report().HANDLER(pager_).str())) :
                optional<path>());

  // Now that the output stream is initialized, report the options that will
  // participate in this report, if the user specified --options

  if (HANDLED(options))
    report_options(report(), report().output_stream);

  // Create an argument scope containing the report command's arguments, and
  // then invoke the command.  The bound scope causes lookups to happen
  // first in the global scope, and then in the report scope.

  call_scope_t command_args(bound_scope);
  for (strings_list::iterator i = arg; i != args.end(); i++)
    command_args.push_back(string_value(*i));

  INFO_START(command, "Finished executing command");
  command(command_args);
  INFO_FINISH(command);
}

int global_scope_t::execute_command_wrapper(strings_list args, bool at_repl)
{
  int status = 1;

  try {
    if (at_repl) push_report();
    execute_command(args, at_repl);
    if (at_repl) pop_report();

    // If we've reached this point, everything succeeded fine.  Ledger uses
    // exceptions to notify of error conditions, so if you're using gdb,
    // just type "catch throw" to find the source point of any error.
    status = 0;
  }
  catch (const std::exception& err) {
    if (at_repl) pop_report();
    report_error(err);
  }

  return status;
}

void global_scope_t::report_options(report_t& report, std::ostream& out)
{
  out << "==============================================================================="
      << std::endl;
  out << "[Global scope options]" << std::endl;

  HANDLER(args_only).report(out);
  HANDLER(debug_).report(out);
  HANDLER(init_file_).report(out);
  HANDLER(script_).report(out);
  HANDLER(trace_).report(out);
  HANDLER(verbose).report(out);
  HANDLER(verify).report(out);
  HANDLER(verify_memory).report(out);

  out << std::endl << "[Session scope options]" << std::endl;
  report.session.report_options(out);

  out << std::endl << "[Report scope options]" << std::endl;
  report.report_options(out);
  out << "==============================================================================="
      << std::endl;
}

option_t<global_scope_t> * global_scope_t::lookup_option(const char * p)
{
  switch (*p) {
  case 'a':
    OPT(args_only);
    break;
  case 'd':
    OPT(debug_);
    break;
  case 'h':
    OPT_(help);
    break;
  case 'i':
    OPT_(init_file_);
    break;
  case 'o':
    OPT(options);
    break;
  case 's':
    OPT(script_);
    break;
  case 't':
    OPT(trace_);
    break;
  case 'v':
    OPT_(verbose);
    else OPT(verify);
    else OPT(verify_memory);
    else OPT(version);
    break;
  }
  return NULL;
}

expr_t::ptr_op_t global_scope_t::lookup(const symbol_t::kind_t kind,
                                        const string& name)
{
  switch (kind) {
  case symbol_t::FUNCTION:
    if (option_t<global_scope_t> * handler = lookup_option(name.c_str()))
      return MAKE_OPT_FUNCTOR(global_scope_t, handler);
    break;

  case symbol_t::OPTION:
    if (option_t<global_scope_t> * handler = lookup_option(name.c_str()))
      return MAKE_OPT_HANDLER(global_scope_t, handler);
    break;

  case symbol_t::PRECOMMAND: {
    const char * p = name.c_str();
    switch (*p) {
    case 'p':
      if (is_eq(p, "push"))
        return MAKE_FUNCTOR(global_scope_t::push_command);
      else if (is_eq(p, "pop"))
        return MAKE_FUNCTOR(global_scope_t::pop_command);
      break;
    }
  }
  default:
    break;
  }

  // If you're wondering how symbols from report() will be found, it's
  // because of the bind_scope_t object in execute_command() below.
  return NULL;
}

void global_scope_t::read_environment_settings(char * envp[])
{
  TRACE_START(environment, 1, "Processed environment variables");

  process_environment(const_cast<const char **>(envp), "LEDGER_", report());

#if 1
  // These are here for backwards compatibility, but are deprecated.

  if (const char * p = std::getenv("LEDGER")) {
    if (! std::getenv("LEDGER_FILE"))
      process_option("environ", "file", report(), p, "LEDGER");
  }
  if (const char * p = std::getenv("LEDGER_INIT")) {
    if (! std::getenv("LEDGER_INIT_FILE"))
      process_option("environ", "init-file", report(), p, "LEDGER_INIT");
  }
  if (const char * p = std::getenv("PRICE_HIST")) {
    if (! std::getenv("LEDGER_PRICE_DB"))
      process_option("environ", "price-db", report(), p, "PRICE_HIST");
  }
  if (const char * p = std::getenv("PRICE_EXP")) {
    if (! std::getenv("LEDGER_PRICE_EXP"))
			process_option("environ", "price-exp", report(), p, "PRICE_EXP");
	}
#endif

  TRACE_FINISH(environment, 1);
}

strings_list
global_scope_t::read_command_arguments(scope_t& scope, strings_list args)
{
  TRACE_START(arguments, 1, "Processed command-line arguments");

  strings_list remaining = process_arguments(args, scope);

  TRACE_FINISH(arguments, 1);

  return remaining;
}

void global_scope_t::normalize_session_options()
{
#if LOGGING_ON
  INFO("Initialization file is " << HANDLER(init_file_).str());
  INFO("Price database is " << session().HANDLER(price_db_).str());

  foreach (const path& pathname, session().HANDLER(file_).data_files)
    INFO("Journal file is " << pathname.string());
#endif // LOGGING_ON
}

expr_t::func_t global_scope_t::look_for_precommand(scope_t&      scope,
                                                   const string& verb)
{
  if (expr_t::ptr_op_t def = scope.lookup(symbol_t::PRECOMMAND, verb))
    return def->as_function();
  else
    return expr_t::func_t();
}

expr_t::func_t global_scope_t::look_for_command(scope_t&      scope,
                                                const string& verb)
{
  if (expr_t::ptr_op_t def = scope.lookup(symbol_t::COMMAND, verb))
    return def->as_function();
  else
    return expr_t::func_t();
}

void global_scope_t::visit_man_page() const
{
#ifndef WIN32
  int pid = fork();
  if (pid < 0) {
    throw std::logic_error(_("Failed to fork child process"));
  }
  else if (pid == 0) {  // child
    execlp("man", "man", "1", "ledger", NULL);

    // We should never, ever reach here
    perror("execlp: man");
    exit(1);
  }

  int status = -1;
  wait(&status);
#endif
  exit(0);                      // parent
}

void handle_debug_options(int argc, char * argv[])
{
  for (int i = 1; i < argc; i++) {
    if (argv[i][0] == '-') {
      if (std::strcmp(argv[i], "--args-only") == 0) {
        args_only = true;
      }
      else if (std::strcmp(argv[i], "--verify-memory") == 0) {
#if VERIFY_ON
        verify_enabled = true;

        _log_level    = LOG_DEBUG;
        _log_category = "memory\\.counts";
#endif
      }
      else if (std::strcmp(argv[i], "--verify") == 0) {
#if VERIFY_ON
        verify_enabled = true;
#endif
      }
      else if (std::strcmp(argv[i], "--verbose") == 0 ||
               std::strcmp(argv[i], "-v") == 0) {
#if LOGGING_ON
        _log_level = LOG_INFO;
#endif
      }
      else if (i + 1 < argc && std::strcmp(argv[i], "--init-file") == 0) {
        _init_file = argv[i + 1];
        i++;
      }
      else if (i + 1 < argc && std::strcmp(argv[i], "--debug") == 0) {
#if DEBUG_ON
        _log_level    = LOG_DEBUG;
        _log_category = argv[i + 1];
        i++;
#endif
      }
      else if (i + 1 < argc && std::strcmp(argv[i], "--trace") == 0) {
#if TRACING_ON
        _log_level   = LOG_TRACE;
        try {
          _trace_level = boost::lexical_cast<uint16_t>(argv[i + 1]);
        }
        catch (const boost::bad_lexical_cast&) {
          throw std::logic_error(_("Argument to --trace must be an integer"));
        }
        i++;
#endif
      }
    }
  }
}

} // namespace ledger
