/*
 * Copyright (c) 2015 Carlos Pizano-Uribe  cpu@chromium.org
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files
 * (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge,
 * publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#include <debug.h>
#include <err.h>
#include <rand.h>
#include <string.h>
#include <trace.h>

#include <kernel/event.h>
#include <kernel/port.h>
#include <kernel/thread.h>

#include <platform.h>

#define LOCAL_TRACE 0

void *context1 = (void *) 0x53;

static void dump_port_result(const port_result_t *result)
{
    const port_packet_t *p = &result->packet;
    LTRACEF("[%02x %02x %02x %02x %02x %02x %02x %02x]\n",
            p->value[0], p->value[1], p->value[2], p->value[3],
            p->value[4], p->value[5], p->value[6], p->value[7]);
}

static int single_thread_basic(void)
{
    port_t w_port;
    status_t st = port_create("sh_prt1", PORT_MODE_UNICAST, &w_port);
    if (st < 0) {
        printf("could not create port, status = %d\n", st);
        return __LINE__;
    }

    port_t r_port;
    st = port_open("sh_prt0", context1, &r_port);
    if (st != ERR_NOT_FOUND) {
        printf("expected not to find port, status = %d\n", st);
        return __LINE__;
    }

    st = port_open("sh_prt1", context1, &r_port);
    if (st < 0) {
        printf("could not open port, status = %d\n", st);
        return __LINE__;
    }

    port_packet_t packet[3] = {
        {{0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08}},
        {{0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11}},
        {{0x33, 0x66, 0x99, 0xcc, 0x33, 0x66, 0x99, 0xcc}},
    };

    st = port_write(w_port, &packet[0], 1);
    if (st < 0) {
        printf("could not write port, status = %d\n", st);
        return __LINE__;
    }

    printf("reading from port:\n");

    port_result_t res = {0};

    st = port_read(r_port, 0, &res);
    if (st < 0) {
        printf("could not read port, status = %d\n", st);
        return __LINE__;
    }
    if (res.ctx != context1) {
        printf("bad context! = %p\n", res.ctx);
        return __LINE__;
    }

    st = port_read(r_port, 0, &res);
    if (st != ERR_TIMED_OUT) {
        printf("expected timeout, status = %d\n", st);
        return __LINE__;
    }

    st = port_write(w_port, &packet[1], 1);
    if (st < 0) {
        printf("could not write port, status = %d\n", st);
        return __LINE__;
    }

    st = port_write(w_port, &packet[0], 1);
    if (st < 0) {
        printf("could not write port, status = %d\n", st);
        return __LINE__;
    }

    st = port_write(w_port, &packet[2], 1);
    if (st < 0) {
        printf("could not write port, status = %d\n", st);
        return __LINE__;
    }

    int expected_count = 3;
    while (true) {
        st = port_read(r_port, 0, &res);
        if (st < 0)
            break;
        dump_port_result(&res);
        --expected_count;
    }

    if (expected_count != 0) {
        printf("invalid read count = %d\n", expected_count);
        return __LINE__;
    }

    printf("\n");

    // port should be empty. should be able to write 8 packets.
    expected_count = 8;
    while (true) {
        st = port_write(w_port, &packet[1], 1);
        if (st < 0)
            break;
        --expected_count;
        st = port_write(w_port, &packet[2], 1);
        if (st < 0)
            break;
        --expected_count;
    }

    if (expected_count != 0) {
        printf("invalid write count = %d\n", expected_count);
        return __LINE__;
    }

    // tod(cpu) fix this possibly wrong error.
    if (st != ERR_PARTIAL_WRITE) {
        printf("expected buffer error, status =%d\n", st);
        return __LINE__;
    }

    // read 3 packets.
    for (int ix = 0; ix != 3; ++ix) {
        st = port_read(r_port, 0, &res);
        if (st < 0) {
            printf("could not read port, status = %d\n", st);
            return __LINE__;
        }
    }

    // there are 5 packets, now we add another 3.
    st = port_write(w_port, packet, 3);
    if (st < 0) {
        printf("could not write port, status = %d\n", st);
        return __LINE__;
    }

    expected_count = 8;
    while (true) {
        st = port_read(r_port, 0, &res);
        if (st < 0)
            break;
        dump_port_result(&res);
        --expected_count;
    }

    if (expected_count != 0) {
        printf("invalid read count = %d\n", expected_count);
        return __LINE__;
    }

    // attempt to use the wrong port.
    st = port_write(r_port, &packet[1], 1);
    if (st !=  ERR_BAD_HANDLE) {
        printf("expected bad handle error, status = %d\n", st);
        return __LINE__;
    }

    st = port_read(w_port, 0, &res);
    if (st !=  ERR_BAD_HANDLE) {
        printf("expected bad handle error, status = %d\n", st);
        return __LINE__;
    }

    st = port_close(r_port);
    if (st < 0) {
        printf("could not close read port, status = %d\n", st);
        return __LINE__;
    }

    st = port_close(w_port);
    if (st < 0) {
        printf("could not close write port, status = %d\n", st);
        return __LINE__;
    }

    st = port_close(r_port);
    if (st != ERR_BAD_HANDLE) {
        printf("expected bad handle error, status = %d\n", st);
        return __LINE__;
    }

    st = port_close(w_port);
    if (st != ERR_BAD_HANDLE) {
        printf("expected bad handle error, status = %d\n", st);
        return __LINE__;
    }

    st = port_destroy(w_port);
    if (st < 0) {
        printf("could not destroy port, status = %d\n", st);
        return __LINE__;
    }

    printf("single_thread_basic : ok\n");
    return 0;
}

static int ping_pong_thread(void *arg)
{
    port_t r_port;
    status_t st = port_open("ping_port", NULL, &r_port);
    if (st < 0) {
        printf("thread: could not open port, status = %d\n", st);
        return __LINE__;
    }

    bool should_dispose_pong_port = true;
    port_t w_port;
    st = port_create("pong_port", PORT_MODE_UNICAST, &w_port);
    if (st == ERR_ALREADY_EXISTS) {
        // won the race to create the port.
        should_dispose_pong_port = false;
    } else if (st < 0) {
        printf("thread: could not open port, status = %d\n", st);
        return __LINE__;
    }

    port_result_t pr;

    // the loop is read-mutate-write until the write port
    // is closed by the master thread.
    while (true) {
        st = port_read(r_port, INFINITE_TIME, &pr);

        if (st == ERR_CANCELLED) {
            break;
        } else if (st < 0) {
            printf("thread: could not read port, status = %d\n", st);
            return __LINE__;
        }

        pr.packet.value[0]++;
        pr.packet.value[5]--;

        st = port_write(w_port, &pr.packet, 1);
        if (st < 0) {
            printf("thread: could not write port, status = %d\n", st);
            return __LINE__;
        }
    }

    port_close(r_port);

    if (should_dispose_pong_port) {
        port_close(w_port);
        port_destroy(w_port);
    }

    return 0;

bail:
    return __LINE__;
}


int two_threads_basic(void)
{
    port_t w_port;
    status_t st = port_create("ping_port", PORT_MODE_BROADCAST, &w_port);
    if (st < 0) {
        printf("could not create port, status = %d\n", st);
        return __LINE__;
    }

    thread_t *t1 = thread_create(
                       "worker1", &ping_pong_thread, NULL, DEFAULT_PRIORITY, DEFAULT_STACK_SIZE);
    thread_t *t2 = thread_create(
                       "worker2", &ping_pong_thread, NULL, DEFAULT_PRIORITY, DEFAULT_STACK_SIZE);
    thread_resume(t1);
    thread_resume(t2);

    // wait for the pong port to be created, the two threads race to do it.
    port_t r_port;
    while (true) {
        status_t st = port_open("pong_port", NULL, &r_port);
        if (st == NO_ERROR) {
            break;
        } else if (st == ERR_NOT_FOUND) {
            thread_sleep(100);
        } else {
            printf("could not open port, status = %d\n", st);
            return __LINE__;
        }
    }

    // We have two threads listening to the ping port. Which both reply
    // on the pong port, so we get two packets in per packet out.
    const int passes = 256;
    printf("two_threads_basic test, %d passes\n", passes);

    port_packet_t packet_out = {{0xaf, 0x77, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05}};

    port_result_t pr;
    for (int ix = 0; ix != passes; ++ix) {
        const size_t count = 1 + ((unsigned int)rand() % 3);

        for (size_t jx = 0; jx != count; ++jx) {
            st = port_write(w_port, &packet_out, 1);
            if (st < 0) {
                printf("could not write port, status = %d\n", st);
                return __LINE__;
            }
        }

        packet_out.value[0]++;
        packet_out.value[5]--;

        for (size_t jx = 0; jx != count * 2; ++jx) {
            st = port_read(r_port, INFINITE_TIME, &pr);
            if (st < 0) {
                printf("could not read port, status = %d\n", st);
                return __LINE__;
            }

            if ((pr.packet.value[0] != packet_out.value[0]) ||
                    (pr.packet.value[5] != packet_out.value[5])) {
                printf("unexpected data in packet, loop %d", ix);
                return __LINE__;
            }
        }
    }

    thread_sleep(100);

    // there should be no more packets to read.
    st = port_read(r_port, 0, &pr);
    if (st != ERR_TIMED_OUT) {
        printf("unexpected packet, status = %d\n", st);
        return __LINE__;
    }

    printf("two_threads_basic master shutdown\n");

    st = port_close(r_port);
    if (st < 0) {
        printf("could not close port, status = %d\n", st);
        return __LINE__;
    }

    st = port_close(w_port);
    if (st < 0) {
        printf("could not close port, status = %d\n", st);
        return __LINE__;
    }

    st = port_destroy(w_port);
    if (st < 0) {
        printf("could not destroy port, status = %d\n", st);
        return __LINE__;
    }

    int retcode = -1;
    thread_join(t1, &retcode, INFINITE_TIME);
    if (retcode)
        goto fail;

    thread_join(t2,  &retcode, INFINITE_TIME);
    if (retcode)
        goto fail;

    return 0;

fail:
    printf("child thread exited with %d\n", retcode);
    return __LINE__;
}

#define CMD_PORT_CTX ((void*) 0x77)
#define TS1_PORT_CTX ((void*) 0x11)
#define TS2_PORT_CTX ((void*) 0x12)

typedef enum {
    ADD_PORT,
    QUIT
} action_t;

typedef struct {
    action_t what;
    port_t port;
} watcher_cmd;

status_t send_watcher_cmd(port_t cmd_port, action_t action, port_t port)
{
    watcher_cmd cmd  = {action, port};
    return port_write(cmd_port, ((port_packet_t *) &cmd), 1);;
}

static int group_watcher_thread(void *arg)
{
    port_t watched[8] = {0};
    status_t st = port_open("grp_ctrl", CMD_PORT_CTX, &watched[0]);
    if (st < 0) {
        printf("could not open port, status = %d\n", st);
        return __LINE__;
    }

    size_t count = 1;
    port_t group;
    int ctx_count = -1;

    while (true) {
        st = port_group(watched, count, &group);
        if (st < 0) {
            printf("could not make group, status = %d\n", st);
            return __LINE__;
        }

        port_result_t pr;
        while (true) {
            st = port_read(group, INFINITE_TIME, &pr);
            if (st < 0) {
                printf("could not read port, status = %d\n", st);
                return __LINE__;
            }

            if (pr.ctx == CMD_PORT_CTX) {
                break;
            } else if (pr.ctx == TS1_PORT_CTX) {
                ctx_count += 1;
            } else if (pr.ctx == TS2_PORT_CTX) {
                ctx_count += 2;
            } else {
                printf("unknown context %p\n", pr.ctx);
                return __LINE__;
            }
        }

        // Either adding a port or exiting; either way close the
        // existing group port and create a new one if needed
        // at the top of the loop.

        port_close(group);
        watcher_cmd *wc = (watcher_cmd *) &pr.packet;

        if (wc->what == ADD_PORT) {
            watched[count++] = wc->port;
        }  else if (wc->what == QUIT) {
            break;
        } else {
            printf("unknown command %d\n", wc->what);
            return __LINE__;
        }
    }

    if (ctx_count !=  2) {
        printf("unexpected context count %d", ctx_count);
        return __LINE__;
    }

    printf("group watcher shutdown\n");

    for (size_t ix = 0; ix != count; ++ix) {
        st = port_close(watched[ix]);
        if (st < 0) {
            printf("failed to close read port, status = %d\n", st);
            return __LINE__;
        }
    }

    return 0;
}

static status_t make_port_pair(const char *name, void *ctx, port_t *write, port_t *read)
{
    status_t st = port_create(name, PORT_MODE_UNICAST, write);
    if (st < 0)
        return st;
    return port_open(name,ctx, read);
}

int group_basic(void)
{
    // we spin a thread that connects to a well known port, then we
    // send two ports that it will add to a group port.
    port_t cmd_port;
    status_t st = port_create("grp_ctrl", PORT_MODE_UNICAST, &cmd_port);
    if (st < 0 ) {
        printf("could not create port, status = %d\n", st);
        return __LINE__;
    }

    thread_t *wt = thread_create(
                       "g_watcher", &group_watcher_thread, NULL, DEFAULT_PRIORITY, DEFAULT_STACK_SIZE);
    thread_resume(wt);

    port_t w_test_port1, r_test_port1;
    st = make_port_pair("tst_port1", TS1_PORT_CTX, &w_test_port1, &r_test_port1);
    if (st < 0)
        return __LINE__;

    port_t w_test_port2, r_test_port2;
    st = make_port_pair("tst_port2", TS2_PORT_CTX, &w_test_port2, &r_test_port2);
    if (st < 0)
        return __LINE__;

    st = send_watcher_cmd(cmd_port, ADD_PORT, r_test_port1);
    if (st < 0)
        return __LINE__;

    st = send_watcher_cmd(cmd_port, ADD_PORT, r_test_port2);
    if (st < 0)
        return __LINE__;

    thread_sleep(50);

    port_packet_t pp = {{0}};
    st = port_write(w_test_port1, &pp, 1);
    if (st < 0)
        return __LINE__;

    st = port_write(w_test_port2, &pp, 1);
    if (st < 0)
        return __LINE__;

    st = send_watcher_cmd(cmd_port, QUIT, 0);
    if (st < 0)
        return __LINE__;

    int retcode = -1;
    thread_join(wt, &retcode, INFINITE_TIME);
    if (retcode) {
        printf("child thread exited with %d\n", retcode);
        return __LINE__;
    }

    st = port_close(w_test_port1);
    if (st < 0)
        return __LINE__;
    st = port_close(w_test_port2);
    if (st < 0)
        return __LINE__;
    st = port_close(cmd_port);
    if (st < 0)
        return __LINE__;
    st = port_destroy(w_test_port1);
    if (st < 0)
        return __LINE__;
    st = port_destroy(w_test_port2);
    if (st < 0)
        return __LINE__;
    st = port_destroy(cmd_port);
    if (st < 0)
        return __LINE__;

    return 0;
}

int group_dynamic(void)
{
    status_t st;

    port_t w_test_port1, r_test_port1;
    st = make_port_pair("tst_port1", TS1_PORT_CTX, &w_test_port1, &r_test_port1);
    if (st < 0)
        return __LINE__;

    port_t w_test_port2, r_test_port2;
    st = make_port_pair("tst_port2", TS2_PORT_CTX, &w_test_port2, &r_test_port2);
    if (st < 0)
        return __LINE__;

    port_t pg;
    st = port_group(&r_test_port1, 1, &pg);
    if (st < 0)
        return __LINE__;

    port_packet_t pkt = { { 0 } };
    st = port_write(w_test_port2, &pkt, 1);
    if (st < 0)
        return __LINE__;

    port_result_t rslt;
    st = port_read(pg, 0, &rslt);
    if (st != ERR_TIMED_OUT)
        return __LINE__;

    // Attach the port that has been written to to the port group and ensure
    // that we can read from it.
    st = port_group_add(pg, r_test_port2);
    if (st < 0)
        return __LINE__;

    st = port_read(pg, 0, &rslt);
    if (st < 0)
        return __LINE__;

    // Write some data to a port then remove it from the port group and ensure
    // that we can't read from it.
    st = port_write(w_test_port1, &pkt, 1);
    if (st < 0)
        return __LINE__;

    st = port_group_remove(pg, r_test_port1);
    if (st < 0)
        return __LINE__;

    st = port_read(pg, 0, &rslt);
    if (st != ERR_TIMED_OUT)
        return __LINE__;

    st = port_close(w_test_port1);
    if (st < 0)
        return __LINE__;
    st = port_close(w_test_port2);
    if (st < 0)
        return __LINE__;
    st = port_destroy(w_test_port1);
    if (st < 0)
        return __LINE__;
    st = port_destroy(w_test_port2);
    if (st < 0)
        return __LINE__;

    return 0;
}

event_t group_waiting_sync_evt;

static int receive_thread(void *arg)
{
    port_t pg = (port_t)arg;

    // Try to read from an empty port group. When the other thread adds a port
    // to this port group, we should wake up and 
    port_result_t rslt;
    status_t st = port_read(pg, 500, &rslt);
    if (st == ERR_TIMED_OUT)
        return __LINE__;

    event_signal(&group_waiting_sync_evt, true);

    return 0;
}

/* Test the edge case where a read port with data available is added to a port
 * group that has a read-blocked receiver.
 */
int group_waiting(void)
{
    status_t st;

    event_init(&group_waiting_sync_evt, false, EVENT_FLAG_AUTOUNSIGNAL);

    port_t w_test_port1, r_test_port1;
    st = make_port_pair("tst_port1", TS1_PORT_CTX, &w_test_port1, &r_test_port1);
    if (st < 0)
        return __LINE__;

    // Write something to this port group that currently has no receivers.
    port_packet_t pkt = { { 0 } };
    st = port_write(w_test_port1, &pkt, 1);
    if (st < 0)
        return __LINE__;

    // Create an empty port group.
    port_t pg;
    st = port_group(NULL, 0, &pg);
    if (st < 0)
        return __LINE__;

    
    thread_t *t1 = thread_create(
        "receiver", 
        &receive_thread, 
        (void *)pg, 
        DEFAULT_PRIORITY, 
        DEFAULT_STACK_SIZE
    );

    thread_resume(t1);

    // Wait for the other thread to block on the read.
    thread_sleep(20);

    // Adding a port that has data available to the port group should wake any
    // threads waiting on that port group.
    port_group_add(pg, r_test_port1);

    if (event_wait_timeout(&group_waiting_sync_evt, 500) != NO_ERROR)
        return __LINE__;

    st = port_close(w_test_port1);
    if (st < 0)
        return __LINE__;

    st = port_destroy(w_test_port1);
    if (st < 0)
        return __LINE__;

    return 0;
}

#define RUN_TEST(t)  result = t(); if (result) goto fail

int port_tests(void)
{
    int result;
    int count = 3;
    while (count--) {
        RUN_TEST(single_thread_basic);
        RUN_TEST(two_threads_basic);
        RUN_TEST(group_basic);
        RUN_TEST(group_dynamic);
    }

    printf("all tests passed\n");
    return 0;
fail:
    printf("test failed at line %d\n", result);
    return 1;
}

#undef RUN_TEST