src/main.cpp

/* Copyright 2025 Mike Becker. All rights reserved.
 *
 * 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.
 *
 * 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 HOLDER 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 "settings.h"
#include "repositories.h"
#include "process.h"

#include <cstdlib>
#include <cstdio>
#include <cstring>
#include <cerrno>

static void print_help() {
    fputs(
        "Usage: fallusmeter [OPTION]... [PATH]...\n\n"
        "Options:\n"
        "   -h, --help             Print this help message\n"
        "   -d, --depth <num>      The search depth (default: 1, max: 255)\n"
        "   -n, --no-pull          Do not pull the repositories\n"
        "   -s, --separate         Output a separate heat map for each repository\n"
        "   -y, --year <year>      The year for which to create the heat map\n"
        "       --hg <path>        Path to hg binary (default: /usr/bin/hg)\n"
        "       --git <path>       Path to git binary (default: /usr/bin/git)\n\n"
        "Scans all specified paths recursively for Mercurial and Git repositories and\n"
        "creates a commit heat map for the specified \033[1myear\033[22m or the current year.\n"
        "By default, the recursion \033[1mdepth\033[22m is one, meaning that this tool assumes that\n"
        "each \033[1mpath\033[22m is either a repository or contains repositories as subdirectories.\n"
        "You can change the \033[1mdepth\033[22m to support other directory structures.\n\n"
        "When you do not specify \033[1m--no-pull\033[22m, this tool will execute the pull command\n"
        "(and for hg the update command) before retrieving the commit log, assuming\n"
        "to be on the default branch with \033[4mno uncommitted changes\033[24m.\n\n"
        "Afterwards, this tool prints an HTML page to stdout. A separate heap map is\n"
        "generated for each author showing commits across all repositories, unless the\n"
        "\033[1m--separate\033[22m option is specified in which case each repository is displayed with\n"
        "its own heat map.\n"
        , stderr);
}

static bool chk_arg(const char *arg, const char *opt1, const char *opt2) {
    return strcmp(arg, opt1) == 0 || (opt2 != nullptr && strcmp(arg, opt2) == 0);
}

template<typename T>
static bool parse_unsigned(const char *str, T *result, unsigned long max) {
    char *endptr;
    errno = 0;
    unsigned long d = strtoul(str, &endptr, 10);
    if (*endptr != '\0' || errno == ERANGE) return true;
    if (d < max) {
        *result = d;
        return false;
    } else {
        return true;
    }
}

static int parse_args(fm::settings &settings, int argc, char *argv[]) {
    for (int i = 1; i < argc; i++) {
        if (chk_arg(argv[i], "-h", "--help")) {
            print_help();
            return -1;
        } else if (chk_arg(argv[i], "-d", "--depth")) {
            if (i + 1 >= argc || parse_unsigned(argv[++i], &settings.depth, 256)) {
                fputs("missing or invalid depth\n", stderr);
                return -1;
            }
        } else if (chk_arg(argv[i], "-y", "--year")) {
            if (i + 1 >= argc || parse_unsigned(argv[++i], &settings.year, 9999)) {
                fputs("missing or invalid year\n", stderr);
                return -1;
            }
        } else if (chk_arg(argv[i], "-n", "--no-pull")) {
            settings.update_repos = false;
        } else if (chk_arg(argv[i], "-s", "--separate")) {
            settings.separate = true;
        } else if (chk_arg(argv[i], "--hg", nullptr)) {
            if (i + 1 < argc) {
                settings.hg.assign(argv[++i]);
            } else {
                fputs("--hg is expecting a path\n", stderr);
                return -1;
            }
        } else if (chk_arg(argv[i], "--git", nullptr)) {
            if (i + 1 < argc) {
                settings.git.assign(argv[++i]);
            } else {
                fputs("--git is expecting a path\n", stderr);
                return -1;
            }
        } else if (argv[i][0] == '-') {
            fprintf(stderr, "Unknown option: %s\n", argv[i]);
            return -1;
        } else {
            settings.paths.emplace_back(argv[i]);
        }
    }

    if (settings.paths.empty()) {
        settings.paths.emplace_back("./");
    }

    return 0;
}

static void print_html_header() {
    puts("<html>\n\t<body>");
}

static void print_html_footer() {
    puts("\t</body>\n</html>");
}

int main(int argc, char *argv[]) {
    // parse settings
    fm::settings settings;
    if (parse_args(settings, argc, argv)) {
        return EXIT_FAILURE;
    }

    // check hg and git
    fm::process proc;
    proc.setbin(settings.hg);
    if (proc.exec({"--version"})) {
        fprintf(stderr, "Testing hg binary '%s' failed!\n", settings.hg.c_str());
        return EXIT_FAILURE;
    }
    proc.setbin(settings.git);
    if (proc.exec({"--version"})) {
        fprintf(stderr, "Testing git binary '%s' failed!\n", settings.git.c_str());
        return EXIT_FAILURE;
    }

    // scan for repos
    fm::repositories repos;
    for (auto &&path: settings.paths) {
        repos.scan(path, settings.depth);
    }

    // update repos, if not disabled
    if (settings.update_repos) {
        for (auto &&repo : repos.list()) {
            proc.chdir(repo.path);
            if (repo.type == fm::HG) {
                proc.setbin(settings.hg);
                if (proc.exec({"pull"})) {
                    fprintf(stderr, "Pulling repo '%s' failed!\nMaybe there is no remote?\n", repo.path.c_str());
                } else if (proc.exec({"update"})) {
                    fprintf(stderr, "Updating repo '%s' failed!\nMaybe there are local changes?\n", repo.path.c_str());
                }
            } else {
                proc.setbin(settings.git);
                if (proc.exec({"pull"})) {
                    fprintf(stderr, "Pulling repo '%s' failed!\nMaybe there is no remote or there are local changes?\n", repo.path.c_str());
                }
            }
        }
    }
    // TODO: calculate the heat maps

    print_html_header();
    // TODO: output the heat maps here
    print_html_footer();

    return EXIT_SUCCESS;
}