// SPDX-License-Identifier: GPL-2.0
#include "tests.h"
#include "debug.h"
#include "symbol.h"
#include "sort.h"
#include "evsel.h"
#include "evlist.h"
#include "machine.h"
#include "parse-events.h"
#include "hists_common.h"
#include "util/mmap.h"
#include <errno.h>
#include <linux/kernel.h>

struct sample {
        u32 pid;
        u64 ip;
        struct thread *thread;
        struct map *map;
        struct symbol *sym;
};

/* For the numbers, see hists_common.c */
static struct sample fake_common_samples[] = {
        /* perf [kernel] schedule() */
        { .pid = FAKE_PID_PERF1, .ip = FAKE_IP_KERNEL_SCHEDULE, },
        /* perf [perf]   main() */
        { .pid = FAKE_PID_PERF2, .ip = FAKE_IP_PERF_MAIN, },
        /* perf [perf]   cmd_record() */
        { .pid = FAKE_PID_PERF2, .ip = FAKE_IP_PERF_CMD_RECORD, },
        /* bash [bash]   xmalloc() */
        { .pid = FAKE_PID_BASH,  .ip = FAKE_IP_BASH_XMALLOC, },
        /* bash [libc]   malloc() */
        { .pid = FAKE_PID_BASH,  .ip = FAKE_IP_LIBC_MALLOC, },
};

static struct sample fake_samples[][5] = {
        {
                /* perf [perf]   run_command() */
                { .pid = FAKE_PID_PERF1, .ip = FAKE_IP_PERF_RUN_COMMAND, },
                /* perf [libc]   malloc() */
                { .pid = FAKE_PID_PERF1, .ip = FAKE_IP_LIBC_MALLOC, },
                /* perf [kernel] page_fault() */
                { .pid = FAKE_PID_PERF1, .ip = FAKE_IP_KERNEL_PAGE_FAULT, },
                /* perf [kernel] sys_perf_event_open() */
                { .pid = FAKE_PID_PERF2, .ip = FAKE_IP_KERNEL_SYS_PERF_EVENT_OPEN, },
                /* bash [libc]   free() */
                { .pid = FAKE_PID_BASH,  .ip = FAKE_IP_LIBC_FREE, },
        },
        {
                /* perf [libc]   free() */
                { .pid = FAKE_PID_PERF2, .ip = FAKE_IP_LIBC_FREE, },
                /* bash [libc]   malloc() */
                { .pid = FAKE_PID_BASH,  .ip = FAKE_IP_LIBC_MALLOC, }, /* will be merged */
                /* bash [bash]   xfee() */
                { .pid = FAKE_PID_BASH,  .ip = FAKE_IP_BASH_XFREE, },
                /* bash [libc]   realloc() */
                { .pid = FAKE_PID_BASH,  .ip = FAKE_IP_LIBC_REALLOC, },
                /* bash [kernel] page_fault() */
                { .pid = FAKE_PID_BASH,  .ip = FAKE_IP_KERNEL_PAGE_FAULT, },
        },
};

static int add_hist_entries(struct evlist *evlist, struct machine *machine)
{
        struct evsel *evsel;
        struct addr_location al;
        struct hist_entry *he;
        struct perf_sample sample = { .period = 1, .weight = 1, };
        size_t i = 0, k;

        /*
         * each evsel will have 10 samples - 5 common and 5 distinct.
         * However the second evsel also has a collapsed entry for
         * "bash [libc] malloc" so total 9 entries will be in the tree.
         */
        evlist__for_each_entry(evlist, evsel) {
                struct hists *hists = evsel__hists(evsel);

                for (k = 0; k < ARRAY_SIZE(fake_common_samples); k++) {
                        sample.cpumode = PERF_RECORD_MISC_USER;
                        sample.pid = fake_common_samples[k].pid;
                        sample.tid = fake_common_samples[k].pid;
                        sample.ip = fake_common_samples[k].ip;

                        if (machine__resolve(machine, &al, &sample) < 0)
                                goto out;

                        he = hists__add_entry(hists, &al, NULL,
                                                NULL, NULL, &sample, true);
                        if (he == NULL) {
                                addr_location__put(&al);
                                goto out;
                        }

                        fake_common_samples[k].thread = al.thread;
                        fake_common_samples[k].map = al.map;
                        fake_common_samples[k].sym = al.sym;
                }

                for (k = 0; k < ARRAY_SIZE(fake_samples[i]); k++) {
                        sample.pid = fake_samples[i][k].pid;
                        sample.tid = fake_samples[i][k].pid;
                        sample.ip = fake_samples[i][k].ip;
                        if (machine__resolve(machine, &al, &sample) < 0)
                                goto out;

                        he = hists__add_entry(hists, &al, NULL,
                                                NULL, NULL, &sample, true);
                        if (he == NULL) {
                                addr_location__put(&al);
                                goto out;
                        }

                        fake_samples[i][k].thread = al.thread;
                        fake_samples[i][k].map = al.map;
                        fake_samples[i][k].sym = al.sym;
                }
                i++;
        }

        return 0;

out:
        pr_debug("Not enough memory for adding a hist entry\n");
        return -1;
}

static int find_sample(struct sample *samples, size_t nr_samples,
                       struct thread *t, struct map *m, struct symbol *s)
{
        while (nr_samples--) {
                if (samples->thread == t && samples->map == m &&
                    samples->sym == s)
                        return 1;
                samples++;
        }
        return 0;
}

static int __validate_match(struct hists *hists)
{
        size_t count = 0;
        struct rb_root_cached *root;
        struct rb_node *node;

        /*
         * Only entries from fake_common_samples should have a pair.
         */
        if (hists__has(hists, need_collapse))
                root = &hists->entries_collapsed;
        else
                root = hists->entries_in;

        node = rb_first_cached(root);
        while (node) {
                struct hist_entry *he;

                he = rb_entry(node, struct hist_entry, rb_node_in);

                if (hist_entry__has_pairs(he)) {
                        if (find_sample(fake_common_samples,
                                        ARRAY_SIZE(fake_common_samples),
                                        he->thread, he->ms.map, he->ms.sym)) {
                                count++;
                        } else {
                                pr_debug("Can't find the matched entry\n");
                                return -1;
                        }
                }

                node = rb_next(node);
        }

        if (count != ARRAY_SIZE(fake_common_samples)) {
                pr_debug("Invalid count for matched entries: %zd of %zd\n",
                         count, ARRAY_SIZE(fake_common_samples));
                return -1;
        }

        return 0;
}

static int validate_match(struct hists *leader, struct hists *other)
{
        return __validate_match(leader) || __validate_match(other);
}

static int __validate_link(struct hists *hists, int idx)
{
        size_t count = 0;
        size_t count_pair = 0;
        size_t count_dummy = 0;
        struct rb_root_cached *root;
        struct rb_node *node;

        /*
         * Leader hists (idx = 0) will have dummy entries from other,
         * and some entries will have no pair.  However every entry
         * in other hists should have (dummy) pair.
         */
        if (hists__has(hists, need_collapse))
                root = &hists->entries_collapsed;
        else
                root = hists->entries_in;

        node = rb_first_cached(root);
        while (node) {
                struct hist_entry *he;

                he = rb_entry(node, struct hist_entry, rb_node_in);

                if (hist_entry__has_pairs(he)) {
                        if (!find_sample(fake_common_samples,
                                         ARRAY_SIZE(fake_common_samples),
                                         he->thread, he->ms.map, he->ms.sym) &&
                            !find_sample(fake_samples[idx],
                                         ARRAY_SIZE(fake_samples[idx]),
                                         he->thread, he->ms.map, he->ms.sym)) {
                                count_dummy++;
                        }
                        count_pair++;
                } else if (idx) {
                        pr_debug("A entry from the other hists should have pair\n");
                        return -1;
                }

                count++;
                node = rb_next(node);
        }

        /*
         * Note that we have a entry collapsed in the other (idx = 1) hists.
         */
        if (idx == 0) {
                if (count_dummy != ARRAY_SIZE(fake_samples[1]) - 1) {
                        pr_debug("Invalid count of dummy entries: %zd of %zd\n",
                                 count_dummy, ARRAY_SIZE(fake_samples[1]) - 1);
                        return -1;
                }
                if (count != count_pair + ARRAY_SIZE(fake_samples[0])) {
                        pr_debug("Invalid count of total leader entries: %zd of %zd\n",
                                 count, count_pair + ARRAY_SIZE(fake_samples[0]));
                        return -1;
                }
        } else {
                if (count != count_pair) {
                        pr_debug("Invalid count of total other entries: %zd of %zd\n",
                                 count, count_pair);
                        return -1;
                }
                if (count_dummy > 0) {
                        pr_debug("Other hists should not have dummy entries: %zd\n",
                                 count_dummy);
                        return -1;
                }
        }

        return 0;
}

static int validate_link(struct hists *leader, struct hists *other)
{
        return __validate_link(leader, 0) || __validate_link(other, 1);
}

int test__hists_link(struct test *test __maybe_unused, int subtest __maybe_unused)
{
        int err = -1;
        struct hists *hists, *first_hists;
        struct machines machines;
        struct machine *machine = NULL;
        struct evsel *evsel, *first;
        struct evlist *evlist = evlist__new();

        if (evlist == NULL)
                return -ENOMEM;

        err = parse_events(evlist, "cpu-clock", NULL);
        if (err)
                goto out;
        err = parse_events(evlist, "task-clock", NULL);
        if (err)
                goto out;

        err = TEST_FAIL;
        /* default sort order (comm,dso,sym) will be used */
        if (setup_sorting(NULL) < 0)
                goto out;

        machines__init(&machines);

        /* setup threads/dso/map/symbols also */
        machine = setup_fake_machine(&machines);
        if (!machine)
                goto out;

        if (verbose > 1)
                machine__fprintf(machine, stderr);

        /* process sample events */
        err = add_hist_entries(evlist, machine);
        if (err < 0)
                goto out;

        evlist__for_each_entry(evlist, evsel) {
                hists = evsel__hists(evsel);
                hists__collapse_resort(hists, NULL);

                if (verbose > 2)
                        print_hists_in(hists);
        }

        first = evlist__first(evlist);
        evsel = evlist__last(evlist);

        first_hists = evsel__hists(first);
        hists = evsel__hists(evsel);

        /* match common entries */
        hists__match(first_hists, hists);
        err = validate_match(first_hists, hists);
        if (err)
                goto out;

        /* link common and/or dummy entries */
        hists__link(first_hists, hists);
        err = validate_link(first_hists, hists);
        if (err)
                goto out;

        err = 0;

out:
        /* tear down everything */
        evlist__delete(evlist);
        reset_output_field();
        machines__exit(&machines);

        return err;
}