// SPDX-License-Identifier: GPL-2.0
#include <dirent.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <sys/param.h>
#include <unistd.h>

#include <api/fs/tracing_path.h>
#include <api/io.h>
#include <linux/stddef.h>
#include <linux/perf_event.h>
#include <linux/zalloc.h>
#include <subcmd/pager.h>

#include "build-id.h"
#include "debug.h"
#include "evsel.h"
#include "metricgroup.h"
#include "parse-events.h"
#include "pmu.h"
#include "pmus.h"
#include "print-events.h"
#include "probe-file.h"
#include "string2.h"
#include "strlist.h"
#include "tracepoint.h"
#include "pfm.h"
#include "thread_map.h"
#include "tool_pmu.h"
#include "util.h"

#define MAX_NAME_LEN 100

/** Strings corresponding to enum perf_type_id. */
static const char * const event_type_descriptors[] = {
        "Hardware event",
        "Software event",
        "Tracepoint event",
        "Hardware cache event",
        "Raw event descriptor",
        "Hardware breakpoint",
};

void print_sdt_events(const struct print_callbacks *print_cb, void *print_state)
{
        struct strlist *bidlist, *sdtlist;
        struct str_node *bid_nd, *sdt_name, *next_sdt_name;
        const char *last_sdt_name = NULL;

        /*
         * The implicitly sorted sdtlist will hold the tracepoint name followed
         * by @<buildid>. If the tracepoint name is unique (determined by
         * looking at the adjacent nodes) the @<buildid> is dropped otherwise
         * the executable path and buildid are added to the name.
         */
        sdtlist = strlist__new(NULL, NULL);
        if (!sdtlist) {
                pr_debug("Failed to allocate new strlist for SDT\n");
                return;
        }
        bidlist = build_id_cache__list_all(true);
        if (!bidlist) {
                pr_debug("Failed to get buildids: %d\n", errno);
                return;
        }
        strlist__for_each_entry(bid_nd, bidlist) {
                struct probe_cache *pcache;
                struct probe_cache_entry *ent;

                pcache = probe_cache__new(bid_nd->s, NULL);
                if (!pcache)
                        continue;
                list_for_each_entry(ent, &pcache->entries, node) {
                        char buf[1024];

                        snprintf(buf, sizeof(buf), "%s:%s@%s",
                                 ent->pev.group, ent->pev.event, bid_nd->s);
                        strlist__add(sdtlist, buf);
                }
                probe_cache__delete(pcache);
        }
        strlist__delete(bidlist);

        strlist__for_each_entry(sdt_name, sdtlist) {
                bool show_detail = false;
                char *bid = (char *)strchr(sdt_name->s, '@');
                char *evt_name = NULL;

                if (bid)
                        *(bid++) = '\0';

                if (last_sdt_name && !strcmp(last_sdt_name, sdt_name->s)) {
                        show_detail = true;
                } else {
                        next_sdt_name = strlist__next(sdt_name);
                        if (next_sdt_name) {
                                const char *bid2 = strchrnul(next_sdt_name->s, '@');

                                show_detail = strncmp(sdt_name->s, next_sdt_name->s, bid2 - next_sdt_name->s) == 0;
                        }
                }
                last_sdt_name = sdt_name->s;

                if (show_detail) {
                        char *path = build_id_cache__origname(bid);

                        if (path) {
                                if (asprintf(&evt_name, "%s@%s(%.12s)", sdt_name->s, path, bid) < 0)
                                        evt_name = NULL;
                                free(path);
                        }
                }
                print_cb->print_event(print_state,
                                /*topic=*/NULL,
                                /*pmu_name=*/NULL,
                                PERF_TYPE_TRACEPOINT,
                                evt_name ?: sdt_name->s,
                                /*event_alias=*/NULL,
                                /*deprecated=*/false,
                                /*scale_unit=*/NULL,
                                "SDT event",
                                /*desc=*/NULL,
                                /*long_desc=*/NULL,
                                /*encoding_desc=*/NULL);

                free(evt_name);
        }
        strlist__delete(sdtlist);
}

bool is_event_supported(u8 type, u64 config)
{
        bool ret = true;
        struct evsel *evsel;
        struct perf_event_attr attr = {
                .type = type,
                .config = config,
                .disabled = 1,
        };
        struct perf_thread_map *tmap = thread_map__new_by_tid(0);

        if (tmap == NULL)
                return false;

        evsel = evsel__new(&attr);
        if (evsel) {
                ret = evsel__open(evsel, NULL, tmap) >= 0;

                if (!ret) {
                        /*
                         * The event may fail to open if the paranoid value
                         * /proc/sys/kernel/perf_event_paranoid is set to 2
                         * Re-run with exclude_kernel set; we don't do that by
                         * default as some ARM machines do not support it.
                         */
                        evsel->core.attr.exclude_kernel = 1;
                        ret = evsel__open(evsel, NULL, tmap) >= 0;
                }

                if (!ret) {
                        /*
                         * The event may fail to open if the PMU requires
                         * exclude_guest to be set (e.g. as the Apple M1 PMU
                         * requires).
                         * Re-run with exclude_guest set; we don't do that by
                         * default as it's equally legitimate for another PMU
                         * driver to require that exclude_guest is clear.
                         */
                        evsel->core.attr.exclude_guest = 1;
                        ret = evsel__open(evsel, NULL, tmap) >= 0;
                }

                evsel__close(evsel);
                evsel__delete(evsel);
        }

        perf_thread_map__put(tmap);
        return ret;
}

/** struct mep - RB-tree node for building printing information. */
struct mep {
        /** nd - RB-tree element. */
        struct rb_node nd;
        /** @metric_group: Owned metric group name, separated others with ';'. */
        char *metric_group;
        const char *metric_name;
        const char *metric_desc;
        const char *metric_long_desc;
        const char *metric_expr;
        const char *metric_threshold;
        const char *metric_unit;
        const char *pmu_name;
};

static int mep_cmp(struct rb_node *rb_node, const void *entry)
{
        struct mep *a = container_of(rb_node, struct mep, nd);
        struct mep *b = (struct mep *)entry;
        int ret;

        ret = strcmp(a->metric_group, b->metric_group);
        if (ret)
                return ret;

        return strcmp(a->metric_name, b->metric_name);
}

static struct rb_node *mep_new(struct rblist *rl __maybe_unused, const void *entry)
{
        struct mep *me = malloc(sizeof(struct mep));

        if (!me)
                return NULL;

        memcpy(me, entry, sizeof(struct mep));
        return &me->nd;
}

static void mep_delete(struct rblist *rl __maybe_unused,
                       struct rb_node *nd)
{
        struct mep *me = container_of(nd, struct mep, nd);

        zfree(&me->metric_group);
        free(me);
}

static struct mep *mep_lookup(struct rblist *groups, const char *metric_group,
                              const char *metric_name)
{
        struct rb_node *nd;
        struct mep me = {
                .metric_group = strdup(metric_group),
                .metric_name = metric_name,
        };
        nd = rblist__find(groups, &me);
        if (nd) {
                free(me.metric_group);
                return container_of(nd, struct mep, nd);
        }
        rblist__add_node(groups, &me);
        nd = rblist__find(groups, &me);
        if (nd)
                return container_of(nd, struct mep, nd);
        return NULL;
}

static int metricgroup__add_to_mep_groups_callback(const struct pmu_metric *pm,
                                        const struct pmu_metrics_table *table __maybe_unused,
                                        void *vdata)
{
        struct rblist *groups = vdata;
        const char *g;
        char *omg, *mg;

        mg = strdup(pm->metric_group ?: pm->metric_name);
        if (!mg)
                return -ENOMEM;
        omg = mg;
        while ((g = strsep(&mg, ";")) != NULL) {
                struct mep *me;

                g = skip_spaces(g);
                if (strlen(g))
                        me = mep_lookup(groups, g, pm->metric_name);
                else
                        me = mep_lookup(groups, pm->metric_name, pm->metric_name);

                if (me) {
                        me->metric_desc = pm->desc;
                        me->metric_long_desc = pm->long_desc;
                        me->metric_expr = pm->metric_expr;
                        me->metric_threshold = pm->metric_threshold;
                        me->metric_unit = pm->unit;
                        me->pmu_name = pm->pmu;
                }
        }
        free(omg);

        return 0;
}

void metricgroup__print(const struct print_callbacks *print_cb, void *print_state)
{
        struct rblist groups;
        struct rb_node *node, *next;
        const struct pmu_metrics_table *table = pmu_metrics_table__find();

        rblist__init(&groups);
        groups.node_new = mep_new;
        groups.node_cmp = mep_cmp;
        groups.node_delete = mep_delete;

        metricgroup__for_each_metric(table, metricgroup__add_to_mep_groups_callback, &groups);

        for (node = rb_first_cached(&groups.entries); node; node = next) {
                struct mep *me = container_of(node, struct mep, nd);

                print_cb->print_metric(print_state,
                                me->metric_group,
                                me->metric_name,
                                me->metric_desc,
                                me->metric_long_desc,
                                me->metric_expr,
                                me->metric_threshold,
                                me->metric_unit,
                                me->pmu_name);
                next = rb_next(node);
                rblist__remove_node(&groups, node);
        }
}

/*
 * Print the help text for the event symbols:
 */
void print_events(const struct print_callbacks *print_cb, void *print_state)
{
        perf_pmus__print_pmu_events(print_cb, print_state);

        print_cb->print_event(print_state,
                        /*topic=*/NULL,
                        /*pmu_name=*/NULL,
                        PERF_TYPE_RAW,
                        "rNNN",
                        /*event_alias=*/NULL,
                        /*scale_unit=*/NULL,
                        /*deprecated=*/false,
                        event_type_descriptors[PERF_TYPE_RAW],
                        /*desc=*/NULL,
                        /*long_desc=*/NULL,
                        /*encoding_desc=*/NULL);

        perf_pmus__print_raw_pmu_events(print_cb, print_state);

        print_cb->print_event(print_state,
                        /*topic=*/NULL,
                        /*pmu_name=*/NULL,
                        PERF_TYPE_BREAKPOINT,
                        "mem:<addr>[/len][:access]",
                        /*scale_unit=*/NULL,
                        /*event_alias=*/NULL,
                        /*deprecated=*/false,
                        event_type_descriptors[PERF_TYPE_BREAKPOINT],
                        /*desc=*/NULL,
                        /*long_desc=*/NULL,
                        /*encoding_desc=*/NULL);

        print_sdt_events(print_cb, print_state);

        metricgroup__print(print_cb, print_state);

        print_libpfm_events(print_cb, print_state);
}