/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include <sys/utsname.h>
#include <errno.h>
#include <stdio.h>

#include "alloc-util.h"
#include "conf-files.h"
#include "constants.h"
#include "env-util.h"
#include "fd-util.h"
#include "fileio.h"
#include "pager.h"
#include "path-util.h"
#include "pretty-print.h"
#include "string-util.h"
#include "strv.h"
#include "terminal-util.h"

void draw_cylon(char buffer[], size_t buflen, unsigned width, unsigned pos) {
        char *p = buffer;

        assert(buflen >= CYLON_BUFFER_EXTRA + width + 1);
        assert(pos <= width+1); /* 0 or width+1 mean that the center light is behind the corner */

        if (pos > 1) {
                if (pos > 2)
                        p = mempset(p, ' ', pos-2);
                if (log_get_show_color())
                        p = stpcpy(p, ANSI_RED);
                *p++ = '*';
        }

        if (pos > 0 && pos <= width) {
                if (log_get_show_color())
                        p = stpcpy(p, ANSI_HIGHLIGHT_RED);
                *p++ = '*';
        }

        if (log_get_show_color())
                p = stpcpy(p, ANSI_NORMAL);

        if (pos < width) {
                if (log_get_show_color())
                        p = stpcpy(p, ANSI_RED);
                *p++ = '*';
                if (pos < width-1)
                        p = mempset(p, ' ', width-1-pos);
                if (log_get_show_color())
                        p = stpcpy(p, ANSI_NORMAL);
        }

        *p = '\0';
}

bool urlify_enabled(void) {
#if ENABLE_URLIFY
        static int cached_urlify_enabled = -1;

        if (cached_urlify_enabled < 0) {
                int val;

                val = getenv_bool("SYSTEMD_URLIFY");
                if (val >= 0)
                        cached_urlify_enabled = val;
                else
                        cached_urlify_enabled = colors_enabled();
        }

        return cached_urlify_enabled;
#else
        return 0;
#endif
}

int terminal_urlify(const char *url, const char *text, char **ret) {
        char *n;

        assert(url);

        /* Takes a URL and a pretty string and formats it as clickable link for the terminal. See
         * https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda for details. */

        if (isempty(text))
                text = url;

        if (urlify_enabled())
                n = strjoin("\x1B]8;;", url, "\a", text, "\x1B]8;;\a");
        else
                n = strdup(text);
        if (!n)
                return -ENOMEM;

        *ret = n;
        return 0;
}

int file_url_from_path(const char *path, char **ret) {
        _cleanup_free_ char *absolute = NULL;
        struct utsname u;
        char *url = NULL;
        int r;

        if (uname(&u) < 0)
                return -errno;

        if (!path_is_absolute(path)) {
                r = path_make_absolute_cwd(path, &absolute);
                if (r < 0)
                        return r;

                path = absolute;
        }

        /* As suggested by https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda, let's include the local
         * hostname here. Note that we don't use gethostname_malloc() or gethostname_strict() since we are interested
         * in the raw string the kernel has set, whatever it may be, under the assumption that terminals are not overly
         * careful with validating the strings either. */

        url = strjoin("file://", u.nodename, path);
        if (!url)
                return -ENOMEM;

        *ret = url;
        return 0;
}

int terminal_urlify_path(const char *path, const char *text, char **ret) {
        _cleanup_free_ char *url = NULL;
        int r;

        assert(path);

        /* Much like terminal_urlify() above, but takes a file system path as input
         * and turns it into a proper file:// URL first. */

        if (isempty(path))
                return -EINVAL;

        if (isempty(text))
                text = path;

        if (!urlify_enabled()) {
                char *n;

                n = strdup(text);
                if (!n)
                        return -ENOMEM;

                *ret = n;
                return 0;
        }

        r = file_url_from_path(path, &url);
        if (r < 0)
                return r;

        return terminal_urlify(url, text, ret);
}

int terminal_urlify_man(const char *page, const char *section, char **ret) {
        const char *url, *text;

        url = strjoina("man:", page, "(", section, ")");
        text = strjoina(page, "(", section, ") man page");

        return terminal_urlify(url, text, ret);
}

typedef enum {
        LINE_SECTION,
        LINE_COMMENT,
        LINE_NORMAL,
} LineType;

static LineType classify_line_type(const char *line, CatFlags flags) {
        const char *t = skip_leading_chars(line, WHITESPACE);

        if ((flags & CAT_FORMAT_HAS_SECTIONS) && *t == '[')
                return LINE_SECTION;
        if (IN_SET(*t, '#', ';', '\0'))
                return LINE_COMMENT;
        return LINE_NORMAL;
}

static int cat_file(const char *filename, bool newline, CatFlags flags) {
        _cleanup_fclose_ FILE *f = NULL;
        _cleanup_free_ char *urlified = NULL, *section = NULL, *old_section = NULL;
        int r;

        f = fopen(filename, "re");
        if (!f)
                return -errno;

        r = terminal_urlify_path(filename, NULL, &urlified);
        if (r < 0)
                return r;

        printf("%s%s# %s%s\n",
               newline ? "\n" : "",
               ansi_highlight_blue(),
               urlified,
               ansi_normal());
        fflush(stdout);

        for (;;) {
                _cleanup_free_ char *line = NULL;

                r = read_line(f, LONG_LINE_MAX, &line);
                if (r < 0)
                        return log_error_errno(r, "Failed to read \"%s\": %m", filename);
                if (r == 0)
                        break;

                LineType line_type = classify_line_type(line, flags);
                if (flags & CAT_TLDR) {
                        if (line_type == LINE_SECTION) {
                                /* The start of a section, let's not print it yet. */
                                free_and_replace(section, line);
                                continue;
                        }

                        if (line_type == LINE_COMMENT)
                                continue;

                        /* Before we print the actual line, print the last section header */
                        if (section) {
                                /* Do not print redundant section headers */
                                if (!streq_ptr(section, old_section))
                                        printf("%s%s%s\n",
                                               ansi_highlight_cyan(),
                                               section,
                                               ansi_normal());

                                free_and_replace(old_section, section);
                        }
                }

                printf("%s%s%s\n",
                       line_type == LINE_SECTION ? ansi_highlight_cyan() :
                       line_type == LINE_COMMENT ? ansi_highlight_grey() :
                       "",
                       line,
                       line_type != LINE_NORMAL ? ansi_normal() : "");
        }

        return 0;
}

int cat_files(const char *file, char **dropins, CatFlags flags) {
        int r;

        if (file) {
                r = cat_file(file, /* newline= */ false, flags);
                if (r < 0)
                        return log_warning_errno(r, "Failed to cat %s: %m", file);
        }

        STRV_FOREACH(path, dropins) {
                r = cat_file(*path, /* newline= */ file || path != dropins, flags);
                if (r < 0)
                        return log_warning_errno(r, "Failed to cat %s: %m", *path);
        }

        return 0;
}

void print_separator(void) {

        /* Outputs a separator line that resolves to whitespace when copied from the terminal. We do that by outputting
         * one line filled with spaces with ANSI underline set, followed by a second (empty) line. */

        if (underline_enabled()) {
                size_t i, c;

                c = columns();

                flockfile(stdout);
                fputs_unlocked(ANSI_UNDERLINE, stdout);

                for (i = 0; i < c; i++)
                        fputc_unlocked(' ', stdout);

                fputs_unlocked(ANSI_NORMAL "\n\n", stdout);
                funlockfile(stdout);
        } else
                fputs("\n\n", stdout);
}

static int guess_type(const char **name, char ***prefixes, bool *is_collection, const char **extension) {
        /* Try to figure out if name is like tmpfiles.d/ or systemd/system-presets/,
         * i.e. a collection of directories without a main config file.
         * Incidentally, all those formats don't use sections. So we return a single
         * is_collection boolean, which also means that the format doesn't use sections.
         */

        _cleanup_free_ char *n = NULL;
        bool usr = false, run = false, coll = false;
        const char *ext = ".conf";
        /* This is static so that the array doesn't get deallocated when we exit the function */
        static const char* const std_prefixes[] = { CONF_PATHS(""), NULL };
        static const char* const usr_prefixes[] = { CONF_PATHS_USR(""), NULL };
        static const char* const run_prefixes[] = { "/run/", NULL };

        if (path_equal(*name, "environment.d"))
                /* Special case: we need to include /etc/environment in the search path, even
                 * though the whole concept is called environment.d. */
                *name = "environment";

        n = strdup(*name);
        if (!n)
                return log_oom();

        /* All systemd-style config files should support the /usr-/etc-/run split and
         * dropins. Let's add a blanket rule that allows us to support them without keeping
         * an explicit list. */
        if (path_startswith(n, "systemd") && endswith(n, ".conf"))
                usr = true;

        delete_trailing_chars(n, "/");

        if (endswith(n, ".d"))
                coll = true;

        if (path_equal(n, "environment"))
                usr = true;

        if (path_equal(n, "udev/hwdb.d"))
                ext = ".hwdb";

        if (path_equal(n, "udev/rules.d"))
                ext = ".rules";

        if (path_equal(n, "kernel/install.d"))
                ext = ".install";

        if (path_equal(n, "systemd/ntp-units.d")) {
                coll = true;
                ext = ".list";
        }

        if (path_equal(n, "systemd/relabel-extra.d")) {
                coll = run = true;
                ext = ".relabel";
        }

        if (PATH_IN_SET(n, "systemd/system-preset", "systemd/user-preset")) {
                coll = true;
                ext = ".preset";
        }

        if (path_equal(n, "systemd/user-preset"))
                usr = true;

        *prefixes = (char**) (usr ? usr_prefixes : run ? run_prefixes : std_prefixes);
        *is_collection = coll;
        *extension = ext;
        return 0;
}

int conf_files_cat(const char *root, const char *name, CatFlags flags) {
        _cleanup_strv_free_ char **dirs = NULL, **files = NULL;
        _cleanup_free_ char *path = NULL;
        char **prefixes = NULL; /* explicit initialization to appease gcc */
        bool is_collection;
        const char *extension;
        int r;

        r = guess_type(&name, &prefixes, &is_collection, &extension);
        if (r < 0)
                return r;
        assert(prefixes);
        assert(extension);

        STRV_FOREACH(prefix, prefixes) {
                assert(endswith(*prefix, "/"));
                r = strv_extendf(&dirs, "%s%s%s", *prefix, name,
                                 is_collection ? "" : ".d");
                if (r < 0)
                        return log_error_errno(r, "Failed to build directory list: %m");
        }

        if (DEBUG_LOGGING) {
                log_debug("Looking for configuration in:");
                if (!is_collection)
                        STRV_FOREACH(prefix, prefixes)
                                log_debug("   %s%s%s", strempty(root), *prefix, name);

                STRV_FOREACH(t, dirs)
                        log_debug("   %s%s/*%s", strempty(root), *t, extension);
        }

        /* First locate the main config file, if any */
        if (!is_collection) {
                STRV_FOREACH(prefix, prefixes) {
                        path = path_join(root, *prefix, name);
                        if (!path)
                                return log_oom();
                        if (access(path, F_OK) == 0)
                                break;
                        path = mfree(path);
                }

                if (!path)
                        printf("%s# Main configuration file %s not found%s\n",
                               ansi_highlight_magenta(),
                               name,
                               ansi_normal());
        }

        /* Then locate the drop-ins, if any */
        r = conf_files_list_strv(&files, extension, root, 0, (const char* const*) dirs);
        if (r < 0)
                return log_error_errno(r, "Failed to query file list: %m");

        /* Show */
        if (is_collection)
                flags |= CAT_FORMAT_HAS_SECTIONS;

        return cat_files(path, files, flags);
}