/*
Copyright (c) 2013 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.

Author: Leonardo de Moura
*/
#include <iostream>
#include <fstream>
#include <signal.h>
#include <cstdlib>
#include <getopt.h>
#include <string>
#include "util/stackinfo.h"
#include "util/debug.h"
#include "util/interrupt.h"
#include "util/script_state.h"
#include "util/thread.h"
#include "util/lean_path.h"
#include "kernel/environment.h"
#include "kernel/kernel_exception.h"
#include "kernel/formatter.h"
#include "kernel/io_state.h"
#include "library/printer.h"
#include "library/kernel_bindings.h"
#include "library/io_state_stream.h"
#include "frontends/lean/parser.h"
#include "frontends/lean/shell.h"
#include "frontends/lean/frontend.h"
#include "frontends/lua/register_modules.h"
#include "version.h"
#include "githash.h" // NOLINT

using lean::shell;
using lean::parser;
using lean::script_state;
using lean::unreachable_reached;
using lean::invoke_debugger;
using lean::notify_assertion_violation;
using lean::environment;
using lean::io_state;

enum class input_kind { Unspecified, Lean, OLean, Lua };

static void on_ctrl_c(int ) {
    lean::request_interrupt();
}

static void display_header(std::ostream & out) {
    out << "Lean (version " << LEAN_VERSION_MAJOR << "." << LEAN_VERSION_MINOR << ", commit " << std::string(g_githash).substr(0, 12) << ")\n";
}

static void display_help(std::ostream & out) {
    display_header(out);
    std::cout << "Input format:\n";
    std::cout << "  --lean            use parser for Lean default input format for files,\n";
    std::cout << "                    with unknown extension (default)\n";
    std::cout << "  --olean           use parser for Lean binary input format for files\n";
    std::cout << "                    with unknown extension\n";
    std::cout << "  --lua             use Lua parser for files with unknown extension\n";
    std::cout << "Miscellaneous:\n";
    std::cout << "  --help -h         display this message\n";
    std::cout << "  --version -v      display version number\n";
    std::cout << "  --githash         display the git commit hash number used to build this binary\n";
    std::cout << "  --path            display the path used for finding Lean libraries and extensions\n";
    std::cout << "  --output=file -o  save the final environment in binary format in the given file\n";
    std::cout << "  --luahook=num -c  how often the Lua interpreter checks the interrupted flag,\n";
    std::cout << "                    it is useful for interrupting non-terminating user scripts,\n";
    std::cout << "                    0 means 'do not check'.\n";
    std::cout << "  --trust -t        trust imported modules\n";
#if defined(LEAN_USE_BOOST)
    std::cout << "  --tstack=num -s   thread stack size in Kb\n";
#endif
}

static char const * get_file_extension(char const * fname) {
    if (fname == 0)
        return 0;
    char const * last_dot = 0;
    while (true) {
        char const * tmp = strchr(fname, '.');
        if (tmp == 0) {
            return last_dot;
        }
        last_dot  = tmp + 1;
        fname = last_dot;
    }
}

static struct option g_long_options[] = {
    {"version",    no_argument,       0, 'v'},
    {"help",       no_argument,       0, 'h'},
    {"lean",       no_argument,       0, 'l'},
    {"olean",      no_argument,       0, 'b'},
    {"lua",        no_argument,       0, 'u'},
    {"nokernel",   no_argument,       0, 'n'},
    {"path",       no_argument,       0, 'p'},
    {"luahook",    required_argument, 0, 'c'},
    {"githash",    no_argument,       0, 'g'},
    {"output",     required_argument, 0, 'o'},
    {"trust",      no_argument,       0, 't'},
#if defined(LEAN_USE_BOOST)
    {"tstack",     required_argument, 0, 's'},
#endif
    {0, 0, 0, 0}
};

int main(int argc, char ** argv) {
    try {
        lean::save_stack_info();
        lean::register_modules();
        bool no_kernel      = false;
        bool export_objects = false;
        bool trust_imported = false;
        std::string output;
        input_kind default_k = input_kind::Lean; // default
        while (true) {
            int c = getopt_long(argc, argv, "tnlupgvhc:012s:012o:", g_long_options, NULL);
            if (c == -1)
                break; // end of command line
            switch (c) {
            case 'v':
                display_header(std::cout);
                return 0;
            case 'g':
                std::cout << g_githash << "\n";
                return 0;
            case 'h':
                display_help(std::cout);
                return 0;
            case 'l':
                default_k = input_kind::Lean;
                break;
            case 'u':
                default_k = input_kind::Lua;
                break;
            case 'b':
                default_k = input_kind::OLean;
                break;
            case 'c':
                script_state::set_check_interrupt_freq(atoi(optarg));
                break;
            case 'p':
                std::cout << lean::get_lean_path() << "\n";
                return 0;
            case 's':
                lean::set_thread_stack_size(atoi(optarg)*1024);
                break;
            case 'n':
                no_kernel = true;
                break;
            case 'o':
                output = optarg;
                export_objects = true;
                break;
            case 't':
                trust_imported = true;
                break;
            default:
                std::cerr << "Unknown command line option\n";
                display_help(std::cerr);
                return 1;
            }
        }
        if (optind >= argc) {
            display_header(std::cout);
            signal(SIGINT, on_ctrl_c);
            if (default_k == input_kind::Lean) {
#if defined(LEAN_WINDOWS)
                std::cout << "Type 'Exit.' to exit or 'Help.' for help."<< std::endl;
#else
                std::cout << "Type Ctrl-D or 'Exit.' to exit or 'Help.' for help."<< std::endl;
#endif
                environment env;
                env->set_trusted_imported(trust_imported);
                io_state ios = init_frontend(env, no_kernel);
                script_state S;
                shell sh(env, &S);
                int status = sh() ? 0 : 1;
                if (export_objects)
                    env->export_objects(output);
                return status;
            } else {
                lean_assert(default_k == input_kind::Lua);
                script_state S;
                S.import("repl");
            }
        } else {
            environment env;
            env->set_trusted_imported(trust_imported);
            io_state    ios = init_frontend(env, no_kernel);
            script_state S;
            bool ok = true;
            for (int i = optind; i < argc; i++) {
                char const * ext = get_file_extension(argv[i]);
                input_kind k     = default_k;
                if (ext) {
                    if (strcmp(ext, "lean") == 0) {
                        k = input_kind::Lean;
                    } else if (strcmp(ext, "olean") == 0) {
                        k = input_kind::OLean;
                    } else if (strcmp(ext, "lua") == 0) {
                        k = input_kind::Lua;
                    }
                }
                if (k == input_kind::Lean) {
                    std::ifstream in(argv[i]);
                    if (in.bad() || in.fail()) {
                        std::cerr << "Failed to open file '" << argv[i] << "'\n";
                        return 1;
                    }
                    if (!parse_commands(env, ios, in, &S, false, false))
                        ok = false;
                } else if (k == input_kind::OLean) {
                    try {
                        env->load(std::string(argv[i]), ios);
                    } catch (lean::exception & ex) {
                        std::cerr << "Failed to load binary file '" << argv[i] << "': " << ex.what() << "\n";
                        ok = false;
                    }
                } else if (k == input_kind::Lua) {
                    try {
                        S.dofile(argv[i]);
                    } catch (lean::exception & ex) {
                        std::cerr << ex.what() << std::endl;
                        ok = false;
                    }
                } else {
                    lean_unreachable(); // LCOV_EXCL_LINE
                }
            }
            if (export_objects)
                env->export_objects(output);
            return ok ? 0 : 1;
        }
    } catch (lean::kernel_exception & ex) {
        std::cerr << "Error: " << ex.pp(lean::mk_simple_formatter(), lean::options()) << "\n";
    } catch (lean::exception & ex) {
        std::cerr << "Error: " << ex.what() << "\n";
    }
}