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

#include <fnmatch.h>
#include <unistd.h>

#include "alloc-util.h"
#include "glob-util.h"
#include "hostname-util.h"
#include "id128-util.h"
#include "journal-util.h"
#include "journalctl.h"
#include "journalctl-util.h"
#include "log.h"
#include "logs-show.h"
#include "nulstr-util.h"
#include "set.h"
#include "string-util.h"
#include "strv.h"
#include "time-util.h"
#include "unit-name.h"

char* format_timestamp_maybe_utc(char *buf, size_t l, usec_t t) {
        assert(buf);

        if (arg_utc)
                return format_timestamp_style(buf, l, t, TIMESTAMP_UTC);

        return format_timestamp(buf, l, t);
}

int acquire_journal(sd_journal **ret) {
        _cleanup_(sd_journal_closep) sd_journal *j = NULL;
        int r;

        assert(ret);

        journal_browse_prepare();

        if (arg_directory)
                r = sd_journal_open_directory(&j, arg_directory, arg_journal_type | arg_journal_additional_open_flags);
        else if (arg_root)
                r = sd_journal_open_directory(&j, arg_root, arg_journal_type | arg_journal_additional_open_flags | SD_JOURNAL_OS_ROOT);
        else if (arg_file_stdin)
                r = sd_journal_open_files_fd(&j, (int[]) { STDIN_FILENO }, 1, arg_journal_additional_open_flags);
        else if (arg_file)
                r = sd_journal_open_files(&j, (const char**) arg_file, arg_journal_additional_open_flags);
        else if (arg_machine) {
                _cleanup_free_ char *u = NULL, *h = NULL;

                r = split_user_at_host(arg_machine, &u, &h);
                if (r < 0)
                        return log_error_errno(r, "Failed to split machine specification '%s': %m", arg_machine);

                if (!isempty(u) && !streq(u, "root"))
                        return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Connecting to a machine as non-root is not supported.");

                r = journal_open_machine(&j, h ?: ".host", arg_journal_additional_open_flags);
        } else
                r = sd_journal_open_namespace(
                                &j,
                                arg_namespace,
                                (arg_merge ? 0 : SD_JOURNAL_LOCAL_ONLY) |
                                arg_namespace_flags | arg_journal_type | arg_journal_additional_open_flags);
        if (r < 0)
                return log_error_errno(r, "Failed to open %s: %m", arg_directory ?: arg_file ? "files" : "journal");

        r = journal_access_check_and_warn(j, arg_quiet,
                                          !(arg_journal_type == SD_JOURNAL_CURRENT_USER || arg_user_units));
        if (r < 0)
                return r;

        *ret = TAKE_PTR(j);
        return 0;
}

bool journal_boot_has_effect(sd_journal *j) {
        assert(j);

        if (arg_boot_offset != 0 &&
            sd_journal_has_runtime_files(j) > 0 &&
            sd_journal_has_persistent_files(j) == 0) {
                log_info("Specifying boot ID or boot offset has no effect, no persistent journal was found.");
                return false;
        }

        return true;
}

int journal_acquire_boot(sd_journal *j) {
        int r;

        assert(j);

        if (!arg_boot)
                return 0;

        /* Take a shortcut and use the current boot_id, which we can do very quickly.
         * We can do this only when the logs are coming from the current machine,
         * so take the slow path if log location is specified. */
        if (arg_boot_offset == 0 && sd_id128_is_null(arg_boot_id) &&
            !arg_directory && !arg_file && !arg_file_stdin && !arg_root) {
                r = id128_get_boot_for_machine(arg_machine, &arg_boot_id);
                if (r < 0)
                        return log_error_errno(r, "Failed to get boot ID%s%s: %m",
                                               isempty(arg_machine) ? "" : " of container ", strempty(arg_machine));
        } else {
                sd_id128_t boot_id;

                r = journal_find_boot(j, arg_boot_id, arg_boot_offset, &boot_id);
                if (r < 0)
                        return log_error_errno(r, "Failed to find journal entry for the specified boot (%s%+i): %m",
                                               sd_id128_is_null(arg_boot_id) ? "" : SD_ID128_TO_STRING(arg_boot_id),
                                               arg_boot_offset);
                if (r == 0)
                        return log_error_errno(SYNTHETIC_ERRNO(ENODATA),
                                               "No journal boot entry found for the specified boot (%s%+i).",
                                               sd_id128_is_null(arg_boot_id) ? "" : SD_ID128_TO_STRING(arg_boot_id),
                                               arg_boot_offset);

                log_debug("Found boot %s for %s%+i",
                          SD_ID128_TO_STRING(boot_id),
                          sd_id128_is_null(arg_boot_id) ? "" : SD_ID128_TO_STRING(arg_boot_id),
                          arg_boot_offset);

                arg_boot_id = boot_id;
        }

        return 1;
}

int get_possible_units(
                sd_journal *j,
                const char *fields,
                char * const *patterns,
                Set **ret) {

        _cleanup_set_free_ Set *found = NULL;
        int r;

        assert(j);
        assert(fields);
        assert(ret);

        NULSTR_FOREACH(field, fields) {
                const void *data;
                size_t size;

                r = sd_journal_query_unique(j, field);
                if (r < 0)
                        return r;

                SD_JOURNAL_FOREACH_UNIQUE(j, data, size) {
                        _cleanup_free_ char *u = NULL;
                        char *eq;

                        eq = memchr(data, '=', size);
                        if (eq) {
                                size -= eq - (char*) data + 1;
                                data = ++eq;
                        }

                        u = strndup(data, size);
                        if (!u)
                                return -ENOMEM;

                        size_t i;
                        if (!strv_fnmatch_full(patterns, u, FNM_NOESCAPE, &i))
                                continue;

                        log_debug("Matched %s with pattern %s=%s", u, field, patterns[i]);
                        r = set_ensure_consume(&found, &string_hash_ops_free, TAKE_PTR(u));
                        if (r < 0)
                                return r;
                }
        }

        *ret = TAKE_PTR(found);
        return 0;
}

int acquire_unit(sd_journal *j, const char *option_name, const char **ret_unit, LogIdType *ret_type) {
        size_t n;
        int r;

        assert(j);
        assert(option_name);
        assert(ret_unit);
        assert(ret_type);

        n = strv_length(arg_system_units) + strv_length(arg_user_units);
        if (n <= 0)
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                       "Using %s requires a unit. Please specify a unit name with -u/--unit=/--user-unit=.",
                                       option_name);
        if (n > 1)
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                       "Using %s with multiple units is not supported.",
                                       option_name);

        LogIdType type;
        char **units;
        if (!strv_isempty(arg_system_units)) {
                type = LOG_SYSTEM_UNIT_INVOCATION_ID;
                units = arg_system_units;
        } else {
                assert(!strv_isempty(arg_user_units));
                type = LOG_USER_UNIT_INVOCATION_ID;
                units = arg_user_units;
        }

        _cleanup_free_ char *u = NULL;
        r = unit_name_mangle(units[0], UNIT_NAME_MANGLE_GLOB | (arg_quiet ? 0 : UNIT_NAME_MANGLE_WARN), &u);
        if (r < 0)
                return log_error_errno(r, "Failed to mangle unit name '%s': %m", units[0]);

        if (string_is_glob(u)) {
                _cleanup_set_free_ Set *s = NULL;

                r = get_possible_units(j, type == LOG_SYSTEM_UNIT_INVOCATION_ID ? SYSTEM_UNITS : USER_UNITS,
                                       STRV_MAKE(u), &s);
                if (r < 0)
                        return log_error_errno(r, "Failed to get matching unit '%s' from journal: %m", u);
                if (set_isempty(s))
                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "No matching unit found for '%s' in journal.", u);
                if (set_size(s) > 1)
                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Multiple matching units found for '%s' in journal.", u);

                char *found = set_steal_first(s);
                log_debug("Found matching unit '%s' for '%s'.", found, u);

                free_and_replace(units[0], found);
                assert(set_isempty(s));
        } else
                free_and_replace(units[0], u);

        *ret_type = type;
        *ret_unit = units[0];
        return 0;
}

int journal_acquire_invocation(sd_journal *j) {
        LogIdType type = LOG_SYSTEM_UNIT_INVOCATION_ID;
        const char *unit = NULL;
        sd_id128_t id;
        int r;

        assert(j);

        /* journal_acquire_boot() must be called before this. */

        if (!arg_invocation) {
                /* Clear relevant field for safety. */
                arg_invocation_id = SD_ID128_NULL;
                arg_invocation_offset = 0;
                return 0;
        }

        /* When an invocation ID is explicitly specified without an offset, we do not care the ID is about
         * system unit or user unit, and calling without unit name is allowed. Otherwise, a unit name must
         * be specified. */
        if (arg_invocation_offset != 0 || sd_id128_is_null(arg_invocation_id)) {
                r = acquire_unit(j, "-I/--invocation= with an offset", &unit, &type);
                if (r < 0)
                        return r;
        }

        r = journal_find_log_id(j, type, arg_boot_id, unit, arg_invocation_id, arg_invocation_offset, &id);
        if (r < 0)
                return log_error_errno(r, "Failed to find journal entry for the invocation (%s%+i): %m",
                                       sd_id128_is_null(arg_invocation_id) ? "" : SD_ID128_TO_STRING(arg_invocation_id),
                                       arg_invocation_offset);
        if (r == 0)
                return log_error_errno(SYNTHETIC_ERRNO(ENODATA),
                                       "No journal entry found for the invocation (%s%+i).",
                                       sd_id128_is_null(arg_invocation_id) ? "" : SD_ID128_TO_STRING(arg_invocation_id),
                                       arg_invocation_offset);

        log_debug("Found invocation ID %s for %s%+i",
                  SD_ID128_TO_STRING(id),
                  sd_id128_is_null(arg_invocation_id) ? "" : SD_ID128_TO_STRING(arg_invocation_id),
                  arg_invocation_offset);

        arg_invocation_id = id;
        return 1;
}
