/*******************************************************************************
 * Copyright (c) 2013-2021, Andrés Martinelli <andmarti@gmail.com>             *
 * All rights reserved.                                                        *
 *                                                                             *
 * This file is a part of sc-im                                                *
 *                                                                             *
 * sc-im is a spreadsheet program that is based on sc. The original authors    *
 * of sc are James Gosling and Mark Weiser, and mods were later added by       *
 * Chuck Martin.                                                               *
 *                                                                             *
 * Redistribution and use in source and binary forms, with or without          *
 * modification, are permitted provided that the following conditions are met: *
 * 1. Redistributions of source code must retain the above copyright           *
 *    notice, this list of conditions and the following disclaimer.            *
 * 2. 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.     *
 * 3. All advertising materials mentioning features or use of this software    *
 *    must display the following acknowledgement:                              *
 *    This product includes software developed by Andrés Martinelli            *
 *    <andmarti@gmail.com>.                                                    *
 * 4. Neither the name of the Andrés Martinelli nor the                        *
 *   names of other contributors may be used to endorse or promote products    *
 *   derived from this software without specific prior written permission.     *
 *                                                                             *
 * THIS SOFTWARE IS PROVIDED BY ANDRES MARTINELLI ''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 ANDRES MARTINELLI 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       *
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.           *
 *******************************************************************************/

/**
 * \file main.c
 * \author Andrés Martinelli <andmarti@gmail.com>
 * \date 2021-05-22
 * \brief The main file of sc-im
 * \details This is the main file for sc-im.
 * \see Homepage: https://github.com/andmarti1424/sc-im
 */

#include <signal.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <fcntl.h>   // for F_GETFL O_NONBLOCK F_SETFL
#include <locale.h>
#include <wchar.h>
#include <sys/ioctl.h> // for ioctl

#ifndef NO_WORDEXP
#include <wordexp.h>
#endif

#include "main.h"
#include "actions/shift.h"
#include "macros.h"
#include "tui.h"
#include "input.h"
#include "cmds/cmds_visual.h"
#include "marks.h"
#include "format.h"
#include "maps.h"
#include "yank.h"
#include "file.h"
#include "utils/dictionary.h"
#include "utils/string.h"
#include "history.h"
#include "conf.h"
#include "buffer.h"
#include "cmds/cmds.h"
#include "vmtbl.h"   // for growtbl
#include "actions/filter.h"
#include "graph.h"
#include "sheet.h"

#ifdef UNDO
#include "undo.h"
#endif

#ifdef XLUA
#include "lua.h"
#endif

// global variable to store a session
struct session * session;

// this variable stores the filename passed to sc-im via argv
// by design, if more than one is passed, we keep the last one.
char loadingfile[PATHLEN] = { '\0' };

// app attributes. TODO: should be later added to conf
int calc_order = BYROWS;
char dpoint = '.'; /* Default decimal point character */
char thsep = ','; /* Default thousands separator character */

// check
char * exepath;
int changed;
int cellassign;
int arg = 1;
int brokenpipe = FALSE; /* Set to true if SIGPIPE is received */
int optimize  = 0; /* Causes numeric expressions to be optimizedv */
int rndtoeven = 0;
int rowsinrange = 1;
int colsinrange = DEFWIDTH;
FILE * fdoutput;  /* Output file descriptor (stdout or file) */

// used by interp
char line[FBUFLEN];
int linelim = -1;
double eval_result;
char * seval_result;


/* shall_quit is a variable to determinate if sc-im must be closed
 * shall_quit=0 means normal operation of app
 * shall_quit=1 means :q
 * shall_quit=-1 means ERROR or SIGABRT signal
 * shall_quit=2 means :q!
 * TODO: add macros here
 */
int shall_quit = 0;

unsigned int curmode;
unsigned int lastmode;

struct block * buffer;
struct block * lastcmd_buffer;
struct dictionary * user_conf_d; /* User's configuration dictionary */
struct history * commandline_history;
struct history * insert_history;
char stderr_buffer[1024] = "";
struct timeval startup_tv, current_tv; /* Runtime timer */

#ifdef AUTOBACKUP
struct timeval lastbackup_tv; /* Last backup timer */
#ifdef HAVE_PTHREAD
#include <pthread.h>
int pthread_exists = 0; /* Return status of pthread_create */
pthread_t fthread;
#endif
#endif

extern graphADT graph;

/**
 * \brief The main() function
 *
 * \details The main() function of sc-im. It is the first function called when
 * the application is executed.
 *
 * \param[in] argc (argument count) is the number of strings pointed to by argv. This
 * is passed to main() by the system.
 *
 * \param[in] argv (argument vector) is a is a one-dimensional array of strings.
 * Each string is one of the arguments that was passed to the program. The
 * first string is the executable's name. This is passed to main() by
 * the system.
 *
 * \return 0 on success; -1 on errors
 */
int main (int argc, char ** argv) {
    // Define how the file stream should be buffered. Error if unsuccessful.
    if (setvbuf(stderr, stderr_buffer, _IOFBF, STDERRBUF) != 0) {
        fprintf(stderr, "Error setting stderr buffer\n");
        return -1;
    }

    // set up signals so we can catch them
    signals();

#ifdef USELOCALE
    // Set location dependent information. This is used by some libraries.
    //setlocale(LC_ALL, "");
    setlocale(LC_CTYPE, "");
#endif

    // start configuration dictionaries
    user_conf_d = create_dictionary();
    store_default_config_values(); // Stores default values in user_conf_d

    // Read the main() parameters and replace values in user_conf_d as necessary
    read_argv(argc, argv);

    // check if help is in argv. if so, show usage and quit
    if (get_conf_int("help")) show_usage_and_quit();

    // check if version is in argv. if so, show version and quit
    if (get_conf_int("version")) show_version_and_quit();

    // if starting tui..
    if (! get_conf_int("nocurses")) {
        // create command line history structure
#ifdef HISTORY_FILE
        commandline_history = (struct history *) create_history(':');
        load_history(commandline_history, ':'); // load the command history file
#endif
#ifdef INS_HISTORY_FILE
        insert_history = (struct history *) create_history('=');
        load_history(insert_history, '='); // load the insert history file
#endif

        // and initiate NCURSES
        ui_start_screen();

#ifdef USECOLORS
        if (get_d_colors_param() == NULL) {
            start_default_ucolors();
        /*
         * in case we decide to change colors
         * this creates a dictionary and stores in it
         * the relationship between macros and the keys values
         * that are defined in .sc files
         */
            set_colors_param_dict();
        }
#endif
    }

    /*
     * If the 'output' parameter is defined, sc-im saves its output to that file.
     * To achieve that, we open the output file and keep it open until exit.
     * otherwise, sc-im will output to stdout.
     */
    if (get_conf_value("output") != NULL) {
        fdoutput = fopen(get_conf_value("output"), "w+");
        if (fdoutput == NULL) {
            sc_error("Cannot open file: %s.", get_conf_value("output"));
            return exit_app(-1);
        }

        if (! get_conf_int("nocurses")) { // WE MUST STOP SCREEN!
            ui_stop_screen();

            // if output is set, nocurses should always be 1 !
            put(user_conf_d, "nocurses", "1");
        }
    }

#ifdef XLUA
    doLuainit();
#endif

    wchar_t stdin_buffer[BUFFERSIZE] = { L'\0' };

    // take this out of here -->
    calc_order = BYROWS;
    prescale = 1.0;
    optimize = 0; // <----

    // create basic structures that will depend on the loaded file
    create_structures();

    // create main session
    session = (struct session *) calloc(1, sizeof(struct session));

    /*
     * create a new roman struct for each file passed as argv
     * and attach it to main session
     * DISABLED BY DESIGN
     * readfile_argv(argc, argv);
     */

    create_empty_wb();

    /*
     * load_rc. Since we are not sure what people put in their scimrc file,
     * other than configuration variables and mappings,
     * we call the load_rc() routine after session / roman / sheet are alloc'ed.
     * See entire 778 issue and 783 PR for details on why this order is set.
     */
    load_rc();

    /* load file passed as argv to sc-im.
     * if more than one file is passed, consider the last one.
     */
    if (strlen(loadingfile))
        load_file(loadingfile);


    // check input from stdin (pipeline)
    // and send it to interp
    read_stdin();

    // change curmode to NORMAL_MODE
    chg_mode('.');

    // initiate ui
    FILE * f;
    if ( ! get_conf_int("nocurses")) {
        // we show welcome screen if no spreadsheet was passed to sc-im
        // and no input was sent throw pipeline
        if ( ! session->cur_doc->name && ! wcslen(stdin_buffer)) {
            ui_do_welcome();
            // show mode and cell's details in status bar
            ui_print_mode();
            ui_show_celldetails();
        } else {
            ui_show_header();
            ui_update(TRUE);
        }
    } else {
        f = fopen("/dev/tty", "rw");
        if (f == NULL) sc_error("fatal error loading stdin");
    }

    // handle input from keyboard
    // this should only take place if curses ui
    if (! get_conf_int("nocurses")) buffer = (struct block *) create_buf();

    wchar_t nocurses_buffer[BUFFERSIZE];

    // runtime timer
    gettimeofday(&startup_tv, NULL);

    #ifdef AUTOBACKUP
    //gettimeofday(&lastbackup_tv, NULL);
    lastbackup_tv = (struct timeval) {0};
    #endif

    // handle --exports passed as argv
    handle_argv_exports();

    while ( ! shall_quit && ! get_conf_int("quit_afterload")) {
        // save current time for runtime timer
        gettimeofday(&current_tv, NULL);

        // autobackup if it is time to do so
        handle_backup();

        // if we are in ncurses
        if (! get_conf_int("nocurses")) {
            handle_input(buffer);

        // if we are not in ncurses
        } else if (fgetws(nocurses_buffer, BUFFERSIZE, f) != NULL) {
            sc_debug("Interp will receive: %ls", nocurses_buffer);
            send_to_interp(nocurses_buffer);
        }

        /*
         * shall_quit=0 means normal operation of app
         * shall_quit=1 means :q
         * shall_quit=-1 means ERROR or ABRT signal
         * shall_quit=2 means :q!
         */
        if (shall_quit == 1 && modcheck()) shall_quit = 0;
    }
    if (get_conf_int("nocurses") && f != NULL) fclose(f);

    return shall_quit == -1 ? exit_app(-1) : exit_app(0);
}


/**
 * \brief Creates the basic structures used by sc-im
 * \return none
 */
void create_structures() {

    // initiate mark array
    create_mark_array();

    // create last command buffer
    lastcmd_buffer = (struct block *) create_buf();

    // create yank list structure
    init_yanklist();

    /* Assign NULL to colformats
    int c;
    for (c = 0; c < COLFORMATS; c++)
        colformat[c] = NULL;
    */

    // init calc chain graph
    graph = GraphCreate();
}


/**
 * \brief read_stdin()
 * \return none
 */
void read_stdin() {
    //sc_debug("reading stdin from pipeline");
    fd_set readfds;
    FD_ZERO(&readfds);
    FD_SET(STDIN_FILENO, &readfds);
    fd_set savefds = readfds;
    struct timeval timeout;
    timeout.tv_sec = 0;
    timeout.tv_usec = 0;
    FILE * f = stdin;
    //FILE * f = fopen("/dev/tty", "rw");
    wchar_t stdin_buffer[BUFFERSIZE] = { L'\0' };

    if (select(1, &readfds, NULL, NULL, &timeout)) {
        //sc_debug("there is data");
        while (f != NULL && fgetws(stdin_buffer, BUFFERSIZE, f) != NULL) {
            sc_debug("Interp will receive: %ls", stdin_buffer);
            send_to_interp(stdin_buffer);
        }
        fflush(f);
    } else {
        //sc_debug("there is NO data");
    }
    readfds = savefds;
    if (f != NULL) fclose(f);

    if ( ! freopen("/dev/tty", "rw", stdin)) {
        perror(NULL);
        exit(-1);
    }
    //sc_debug("finish reading");
}


/**
 * \brief Delete basic structures that depend on the loaded files.
 * \return none
 */
void delete_structures() {

    // Free marks array
    free_marks_array();

    // Free yanklist
    free_yanklist();

    // free custom col formats
    free_formats();

    // Erase last_command buffer
    erase_buf(lastcmd_buffer);

    // Free ranges
    free_ranges();

    // Free filters
    free_filters();

    // Free undo list - from start of list
#ifdef UNDO
    clear_undo_list();
#endif

    // free deleted ents
    flush_saved();

    // free calc chain graph
    destroy_graph(graph);

    // Free tbl / sheet / roman / session
    free_session(session);

    // free custom_colors
    free_custom_colors();

    // Free lua stuff
#ifdef XLUA
    doLuaclose();
#endif
}


/**
 * \brief Cleans things up just before exiting the program.
 *
 * \param[in] status
 * \param[out] status
 *
 * \return status is returned unchanged:
 *         return 0 on normal exit.
 *         return -1 on error.
 */
int exit_app(int status) {
    // free history
    if (! get_conf_int("nocurses")) {

#ifdef HISTORY_FILE
        if (! save_history(commandline_history, "w")) sc_error("Could not save commandline history");
        if (commandline_history != NULL) destroy_history(commandline_history);
#endif

#ifdef INS_HISTORY_FILE
        if (! save_history(insert_history, "a")) sc_error("Could not save input mode history");
        if (insert_history != NULL) destroy_history(insert_history);
#endif
    }

    // wait for autobackup thread to finish, just in case
    #if defined(AUTOBACKUP) && defined(HAVE_PTHREAD)
    if (pthread_exists) pthread_join (fthread, NULL);
    #endif

    // remove backup file
#ifdef AUTOBACKUP
    char * filename = session->cur_doc->name;
    if (filename != NULL && strlen(filename) && backup_exists(filename)) remove_backup(filename);
#endif

    // erase structures
    delete_structures();

    // Free mappings
    del_maps();

    // Erase stdin
    erase_buf(buffer);

    // stop CURSES screen
    if (! get_conf_int("nocurses"))
        ui_stop_screen();

    // close fdoutput
    if (get_conf_value("output") != NULL && get_conf_value("output")[0] != '\0' && fdoutput != NULL) {
        fclose(fdoutput);
    }

    // delete user config dictionaries
    destroy_dictionary(user_conf_d);

    return status;
}


/**
 * \brief Read command line parameters and store them in a dictionary
 *
 * \details Read parameters passed to sc-im executable and
 * store them in user_conf dictionary.
 *
 * \param[in] argc (argument count) is the number of strings pointed to by
 * argv.
 * \param[in] argv (argument vector) is a one-dimensional array of strings.
 * Each string is one of the arguments that was passed to the program. The
 * first string is the executable's name.
 *
 * \return none
 */
void read_argv(int argc, char ** argv) {
    int i;
    for (i = 1; i < argc; i++) {
        if ( ! strncmp(argv[i], "--", 2) ) {       // it was passed a parameter
            parse_str(user_conf_d, argv[i] + 2, 0);
        } else {                                   // it was passed a file
            //printf("%s-\n", argv[i]);
            strncpy(loadingfile, argv[i], PATHLEN-1);
        }
    }
    exepath = argv[0];
    return;
}


/**
 * \brief handle_argv_exports()
 * TODO: move to a new offline.c
 * \return none
 */
void handle_argv_exports() {
    if (get_conf_value("export_csv") && session->cur_doc != NULL) {
        export_delim(NULL, ',', 0, 0, session->cur_doc->cur_sh->maxrow, session->cur_doc->cur_sh->maxcol, 0);
    }

    if (get_conf_value("export_tab") && session->cur_doc != NULL) {
        export_delim(NULL, '\t', 0, 0, session->cur_doc->cur_sh->maxrow, session->cur_doc->cur_sh->maxcol, 0);
    }

    if (get_conf_value("export_mkd") && session->cur_doc != NULL) {
        export_markdown(NULL, 0, 0, session->cur_doc->cur_sh->maxrow, session->cur_doc->cur_sh->maxcol);
    }

    if ((get_conf_value("export") || get_conf_value("export_txt")) && session->cur_doc != NULL) {
        export_plain(NULL, 0, 0, session->cur_doc->cur_sh->maxrow, session->cur_doc->cur_sh->maxcol);
    }
    return;
}


/**
 * \brief Set up signals caught by sc-im
 * \return none
 */
void signals() {
    void sig_int();
    void sig_abrt();
    void sig_term();
    void sig_nopipe();
    void sig_winchg();
    void sig_tstp();
    void sig_cont();

    signal(SIGINT, sig_int);
    signal(SIGABRT, sig_abrt);
    signal(SIGTERM, sig_term); // kill
    signal(SIGPIPE, sig_nopipe);
    //(void) signal(SIGALRM, time_out);
    signal(SIGWINCH, sig_winchg);
    //(void) signal(SIGBUS, doquit);
    //(void) signal(SIGFPE, doquit);
    signal(SIGTSTP, sig_tstp);
    signal(SIGCONT, sig_cont);
    return;
}


/**
 * \brief Handles the SIGPIPE signal
 * \return none
 */
void sig_nopipe() {
    sc_error("brokenpipe!");
    brokenpipe = TRUE;
    return;
}


/**
 * \brief Handles the SIGTSTP signal
 * \return none
 */
void sig_tstp() {
    //sc_info("Got SIGTSTP.");
    def_prog_mode();
    endwin();
    signal(SIGTSTP, SIG_DFL);  /* set handler to default */
    kill(getpid(), SIGTSTP);   /* call the default handler */
}


/**
 * \brief Handles the SIGCONT signal
 * \return none
 */
void sig_cont() {
    signal(SIGTSTP, sig_tstp); /* set handler back to this */
    sig_winchg();
    reset_prog_mode();
    refresh();
    ui_update(TRUE);
    //sc_info("Got SIGCONT.");
}


/**
 * \brief Handles the SIGINT signal
 * \return none
 */
void sig_int() {
    sc_info("Got SIGINT.%s" , curmode != NORMAL_MODE ? " Back to NORMAL_MODE" : " Press «:q<Enter>» to quit sc-im");
    if (get_bufsize(buffer)) break_waitcmd_loop(buffer);
    if (curmode == VISUAL_MODE) exit_visualmode();
    chg_mode('.');
    inputline[0] = L'\0';  // clean inputline
    flush_buf(buffer);
    ui_update(TRUE);
    /*
    if ( ! get_conf_int("debug")) {
        sc_error("Got SIGINT. Press «:q<Enter>» to quit sc-im");
    } else if (get_bufsize(buffer)) {
        break_waitcmd_loop(buffer);
    } else {
        shall_quit = 2;
    }
    */
    return;
}


/**
 * \brief Handles the SIGABRT signal
 * \return none
 */
void sig_abrt() {
    sc_error("Error !!! Quitting sc-im.");
    shall_quit = -1; // error !
    return;
}


/**
 * \brief Handles the SIGABRT signal
 * \return none
 */
void sig_term() {
    sc_error("Got SIGTERM signal. Quitting sc-im.");
    shall_quit = 2;
    return;
}