/***
  This file is part of libsydney.

  Copyright 2007-2008 Lennart Poettering

  libsydney is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as
  published by the Free Software Foundation, either version 2.1 of the
  License, or (at your option) any later version.

  libsydney is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with libsydney. If not, see
  <http://www.gnu.org/licenses/>.
***/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <ltdl.h>
#include <string.h>
#include <errno.h>

#include "driver.h"
#include "common.h"
#include "malloc.h"
#include "driver-order.h"

struct private_dso {
    lt_dlhandle module;
    sa_bool_t ltdl_initialized;

    int (*driver_open)(sa_stream *s);
    int (*driver_destroy)(sa_stream *s);


    int (*driver_change_write_latency)(sa_stream *s, size_t *overall_latency, size_t *immutable_latency, size_t *process_time);
    int (*driver_change_read_latency)(sa_stream *s, size_t *overall_latency, size_t *process_time);

    int (*driver_change_device)(sa_stream *s, const char *device);
    int (*driver_change_read_volume)(sa_stream *s, const int32_t vol[]);
    int (*driver_change_write_volume)(sa_stream *s, const int32_t vol[]);
    int (*driver_change_pcm_rate)(sa_stream *s, unsigned rate);

    int (*driver_change_props)(sa_stream *s, sa_proplist *changed, sa_proplist *merged);

    int (*driver_get_state)(sa_stream *s, sa_state_t *state);
    int (*driver_get_position)(sa_stream *s, sa_position_t position, int64_t *pos);

    int (*driver_wait)(sa_stream *s);

    int (*driver_read)(sa_stream *s, void *data, size_t nbytes);
    int (*driver_read_ni)(sa_stream *s, unsigned channel, void *data, size_t nbytes);

    int (*driver_pwrite)(sa_stream *s, const void *data, size_t nbytes, int64_t offset, sa_seek_t whence);
    int (*driver_pwrite_ni)(sa_stream *s, unsigned channel, const void *data, size_t nbytes, int64_t offset, sa_seek_t whence);

    int (*driver_get_read_size)(sa_stream *s, size_t *size);
    int (*driver_get_write_size)(sa_stream *s, size_t *size);

    int (*driver_resume)(sa_stream *s);
    int (*driver_pause)(sa_stream *s);
    int (*driver_drain)(sa_stream *s);
};

#define PRIVATE_DSO(s) ((struct private_dso *) ((s)->private_dso))

static int sa_error_from_lt_error(int code) {

    static const int table[] = {
        [LT_ERROR_UNKNOWN] = SA_ERROR_INTERNAL,
        [LT_ERROR_DLOPEN_NOT_SUPPORTED] = SA_ERROR_NOTSUPPORTED,
        [LT_ERROR_INVALID_LOADER] = SA_ERROR_INTERNAL,
        [LT_ERROR_INIT_LOADER] = SA_ERROR_INTERNAL,
        [LT_ERROR_REMOVE_LOADER] = SA_ERROR_INTERNAL,
        [LT_ERROR_FILE_NOT_FOUND] = SA_ERROR_NOTFOUND,
        [LT_ERROR_DEPLIB_NOT_FOUND] = SA_ERROR_NOTFOUND,
        [LT_ERROR_NO_SYMBOLS] = SA_ERROR_NOTFOUND,
        [LT_ERROR_CANNOT_OPEN] = SA_ERROR_ACCESS,
        [LT_ERROR_CANNOT_CLOSE] = SA_ERROR_INTERNAL,
        [LT_ERROR_SYMBOL_NOT_FOUND] = SA_ERROR_NOTFOUND,
        [LT_ERROR_NO_MEMORY] = SA_ERROR_OOM,
        [LT_ERROR_INVALID_HANDLE] = SA_ERROR_INVALID,
        [LT_ERROR_BUFFER_OVERFLOW] = SA_ERROR_TOOBIG,
        [LT_ERROR_INVALID_ERRORCODE] = SA_ERROR_INVALID,
        [LT_ERROR_SHUTDOWN] = SA_ERROR_INTERNAL,
        [LT_ERROR_CLOSE_RESIDENT_MODULE] = SA_ERROR_INTERNAL,
        [LT_ERROR_INVALID_MUTEX_ARGS] = SA_ERROR_INTERNAL,
        [LT_ERROR_INVALID_POSITION] = SA_ERROR_INTERNAL
    };

    if (code < 0 || code >= LT_ERROR_MAX)
        return SA_ERROR_INTERNAL;

    return table[code];
}

static int lt_error_from_string(const char *t) {

    struct lt_error_code {
        int code;
        const char *text;
    };

    static const struct lt_error_code lt_error_codes[] = {
        /* This is so disgustingly ugly, it makes me vomit. But that's
         * all ltdl's fault. */
#define LT_ERROR(u, s) { .code = LT_ERROR_ ## u, .text = s },
        lt_dlerror_table
#undef LT_ERROR

        { .code = 0, .text = NULL }
    };

    const struct lt_error_code *c;

    for (c = lt_error_codes; c->text; c++)
        if (sa_streq(t, c->text))
            return c->code;

    return -1;
}

static int sa_error_from_string(const char *t) {
    int err;

    if ((err = lt_error_from_string(t)) < 0)
        return SA_ERROR_INTERNAL;

    return sa_error_from_lt_error(err);
}

static int try_open(sa_stream *s, const char *t) {
    char *mn;
    struct private_dso *p;

    p = PRIVATE_DSO(s);

    if (!(mn = sa_sprintf_malloc(SA_PLUGIN_PATH "/libsydney-%s", t)))
        return SA_ERROR_OOM;

    errno = 0;
    p->module = lt_dlopenext(mn);
    sa_free(mn);

    if (!p->module) {
        int ret;

        if (errno == ENOENT)
            ret = SA_ERROR_NOTFOUND;
        else
            ret = sa_error_from_string(lt_dlerror());

        if (ret == SA_ERROR_NOTFOUND)
            ret = SA_ERROR_NODRIVER;

        return ret;
    }

    return SA_SUCCESS;
}

static void* real_dlsym(lt_module m, const char *name, const char *symbol) {
    char sn[256];
    char *s;
    void *r;

    sa_return_null_if_fail(m);
    sa_return_null_if_fail(name);
    sa_return_null_if_fail(symbol);

    snprintf(sn, sizeof(sn), "%s_%s", name, symbol);
    sn[sizeof(sn)-1] = 0;

    for (s = sn; *s; s++) {
        if (*s >= 'a' && *s <= 'z')
            continue;
        if (*s >= 'A' && *s <= 'Z')
            continue;
        if (*s >= '0' && *s <= '9')
            continue;

        *s = '_';
    }

    if ((r = lt_dlsym(m, sn)))
        return r;

    return lt_dlsym(m, symbol);
}

#define MAKE_FUNC_PTR(ret, args, x) ((ret (*) args ) (size_t) (x))
#define GET_FUNC_PTR(module, name, symbol, ret, args) MAKE_FUNC_PTR(ret, args, real_dlsym((module), (name), (symbol)))

int driver_open(sa_stream *s) {
    int ret;
    struct private_dso *p;
    char *driver;

    sa_return_val_if_fail(s, SA_ERROR_INVALID);
    sa_return_val_if_fail(!PRIVATE_DSO(s), SA_ERROR_STATE);

    if (!(s->private_dso = p = sa_new0(struct private_dso, 1)))
        return SA_ERROR_OOM;

    if (lt_dlinit() != 0) {
        ret = sa_error_from_string(lt_dlerror());
        driver_destroy(s);
        return ret;
    }

    p->ltdl_initialized = TRUE;

    if (s->driver) {
        char *e;
        size_t n;

        if (!(e = sa_strdup(s->driver))) {
            driver_destroy(s);
            return SA_ERROR_OOM;
        }

        n = strcspn(e, ",:");
        e[n] = 0;

        if (n == 0) {
            driver_destroy(s);
            sa_free(e);
            return SA_ERROR_INVALID;
        }

        if ((ret = try_open(s, e)) < 0) {
            driver_destroy(s);
            sa_free(e);
            return ret;
        }

        driver = e;

    } else {
        const char *const * e;

        for (e = sa_driver_order; *e; e++) {

            if ((ret = try_open(s, *e)) == SA_SUCCESS)
                break;

            if (ret != SA_ERROR_NODRIVER &&
                ret != SA_ERROR_NOTAVAILABLE &&
                ret != SA_ERROR_NOTFOUND) {

                driver_destroy(s);
                return ret;
            }
        }

        if (!*e) {
            driver_destroy(s);
            return SA_ERROR_NODRIVER;
        }

        if (!(driver = sa_strdup(*e))) {
            driver_destroy(s);
            return SA_ERROR_OOM;
        }
    }

    sa_assert(p->module);

    if (!(p->driver_open = GET_FUNC_PTR(p->module, driver, "driver_open", int, (sa_stream*))) ||
        !(p->driver_destroy = GET_FUNC_PTR(p->module, driver, "driver_destroy", int, (sa_stream*))) ||
        !(p->driver_change_write_latency = GET_FUNC_PTR(p->module, driver, "driver_change_write_latency", int, (sa_stream *, size_t *, size_t *, size_t *_time))) ||
        !(p->driver_change_read_latency = GET_FUNC_PTR(p->module, driver, "driver_change_read_latency", int, (sa_stream *, size_t *, size_t *_time))) ||
        !(p->driver_change_device = GET_FUNC_PTR(p->module, driver, "driver_change_device", int, (sa_stream*, const char *))) ||
        !(p->driver_change_read_volume = GET_FUNC_PTR(p->module, driver, "driver_change_read_volume", int, (sa_stream *s, const int32_t[]))) ||
        !(p->driver_change_write_volume = GET_FUNC_PTR(p->module, driver, "driver_change_write_volume", int, (sa_stream *s, const int32_t[]))) ||
        !(p->driver_change_pcm_rate = GET_FUNC_PTR(p->module, driver, "driver_change_pcm_rate", int, (sa_stream *, unsigned))) ||
        !(p->driver_change_props = GET_FUNC_PTR(p->module, driver, "driver_change_props", int, (sa_stream *, sa_proplist *, sa_proplist *))) ||
        !(p->driver_get_state = GET_FUNC_PTR(p->module, driver, "driver_get_state", int, (sa_stream *, sa_state_t *))) ||
        !(p->driver_get_position = GET_FUNC_PTR(p->module, driver, "driver_get_position", int, (sa_stream *s, sa_position_t position, int64_t *pos))) ||
        !(p->driver_wait = GET_FUNC_PTR(p->module, driver, "driver_wait", int, (sa_stream *s))) ||
        !(p->driver_read = GET_FUNC_PTR(p->module, driver, "driver_read", int, (sa_stream *s, void *data, size_t nbytes))) ||
        !(p->driver_read_ni = GET_FUNC_PTR(p->module, driver, "driver_read_ni", int, (sa_stream *s, unsigned channel, void *data, size_t nbytes))) ||
        !(p->driver_pwrite = GET_FUNC_PTR(p->module, driver, "driver_pwrite", int, (sa_stream *s, const void *data, size_t nbytes, int64_t offset, sa_seek_t whence))) ||
        !(p->driver_pwrite_ni = GET_FUNC_PTR(p->module, driver, "driver_pwrite_ni", int, (sa_stream *s, unsigned channel, const void *data, size_t nbytes, int64_t offset, sa_seek_t whence))) ||
        !(p->driver_get_read_size = GET_FUNC_PTR(p->module, driver, "driver_get_read_size", int, (sa_stream *s, size_t *size))) ||
        !(p->driver_get_write_size = GET_FUNC_PTR(p->module, driver, "driver_get_write_size", int, (sa_stream *s, size_t *size))) ||
        !(p->driver_resume = GET_FUNC_PTR(p->module, driver, "driver_resume", int, (sa_stream *s))) ||
        !(p->driver_pause = GET_FUNC_PTR(p->module, driver, "driver_pause", int, (sa_stream *s))) ||
        !(p->driver_drain = GET_FUNC_PTR(p->module, driver, "driver_drain", int, (sa_stream *s)))) {

        sa_free(driver);
        driver_destroy(s);
        return SA_ERROR_CORRUPT;
    }

    sa_free(driver);

    if ((ret = p->driver_open(s)) < 0) {
        driver_destroy(s);
        return ret;
    }

    return SA_SUCCESS;
}

int driver_destroy(sa_stream *s) {
    struct private_dso *p;
    int ret = SA_SUCCESS;

    sa_return_val_if_fail(s, SA_ERROR_INVALID);
    sa_return_val_if_fail(s->private_dso, SA_ERROR_STATE);

    p = PRIVATE_DSO(s);

    if (p->driver_destroy)
        ret = p->driver_destroy(s);

    if (p->module)
        lt_dlclose(p->module);

    if (p->ltdl_initialized) {
        lt_dlexit();
        p->ltdl_initialized = FALSE;
    }

    sa_free(p);

    s->private_dso = NULL;

    return ret;
}

int driver_change_write_latency(sa_stream *s, size_t *overall_latency, size_t *immutable_latency, size_t *process_time) {
    struct private_dso *p;

    sa_return_val_if_fail(s, SA_ERROR_INVALID);
    sa_return_val_if_fail(s->private_dso, SA_ERROR_STATE);

    p = PRIVATE_DSO(s);
    sa_return_val_if_fail(p->driver_change_write_latency, SA_ERROR_STATE);

    return p->driver_change_write_latency(s, overall_latency, immutable_latency, process_time);
}

int driver_change_read_latency(sa_stream *s, size_t *latency, size_t *process_time) {
    struct private_dso *p;

    sa_return_val_if_fail(s, SA_ERROR_INVALID);
    sa_return_val_if_fail(s->private_dso, SA_ERROR_STATE);

    p = PRIVATE_DSO(s);
    sa_return_val_if_fail(p->driver_change_read_latency, SA_ERROR_STATE);

    return p->driver_change_read_latency(s, latency, process_time);
}

int driver_change_device(sa_stream *s, const char *device) {
    struct private_dso *p;

    sa_return_val_if_fail(s, SA_ERROR_INVALID);
    sa_return_val_if_fail(s->private_dso, SA_ERROR_STATE);

    p = PRIVATE_DSO(s);
    sa_return_val_if_fail(p->driver_change_device, SA_ERROR_STATE);

    return p->driver_change_device(s, device);
}

int driver_change_read_volume(sa_stream *s, const int32_t vol[]) {
    struct private_dso *p;

    sa_return_val_if_fail(s, SA_ERROR_INVALID);
    sa_return_val_if_fail(s->private_dso, SA_ERROR_STATE);

    p = PRIVATE_DSO(s);
    sa_return_val_if_fail(p->driver_change_read_volume, SA_ERROR_STATE);

    return p->driver_change_read_volume(s, vol);
}

int driver_change_write_volume(sa_stream *s, const int32_t vol[]) {
    struct private_dso *p;

    sa_return_val_if_fail(s, SA_ERROR_INVALID);
    sa_return_val_if_fail(s->private_dso, SA_ERROR_STATE);

    p = PRIVATE_DSO(s);
    sa_return_val_if_fail(p->driver_change_write_volume, SA_ERROR_STATE);

    return p->driver_change_write_volume(s, vol);
}

int driver_change_pcm_rate(sa_stream *s, unsigned rate) {
    struct private_dso *p;

    sa_return_val_if_fail(s, SA_ERROR_INVALID);
    sa_return_val_if_fail(s->private_dso, SA_ERROR_STATE);

    p = PRIVATE_DSO(s);
    sa_return_val_if_fail(p->driver_change_pcm_rate, SA_ERROR_STATE);

    return p->driver_change_pcm_rate(s, rate);
}

int driver_change_props(sa_stream *s, sa_proplist *changed, sa_proplist *merged) {
    struct private_dso *p;

    sa_return_val_if_fail(s, SA_ERROR_INVALID);
    sa_return_val_if_fail(s->private_dso, SA_ERROR_STATE);

    p = PRIVATE_DSO(s);
    sa_return_val_if_fail(p->driver_change_props, SA_ERROR_STATE);

    return p->driver_change_props(s, changed, merged);
}

int driver_get_state(sa_stream *s, sa_state_t *state) {
    struct private_dso *p;

    sa_return_val_if_fail(s, SA_ERROR_INVALID);
    sa_return_val_if_fail(s->private_dso, SA_ERROR_STATE);

    p = PRIVATE_DSO(s);
    sa_return_val_if_fail(p->driver_get_state, SA_ERROR_STATE);

    return p->driver_get_state(s, state);
}

int driver_get_position(sa_stream *s, sa_position_t position, int64_t *pos) {
    struct private_dso *p;

    sa_return_val_if_fail(s, SA_ERROR_INVALID);
    sa_return_val_if_fail(s->private_dso, SA_ERROR_STATE);

    p = PRIVATE_DSO(s);
    sa_return_val_if_fail(p->driver_get_position, SA_ERROR_STATE);

    return p->driver_get_position(s, position, pos);
}

int driver_wait(sa_stream *s) {
    struct private_dso *p;

    sa_return_val_if_fail(s, SA_ERROR_INVALID);
    sa_return_val_if_fail(s->private_dso, SA_ERROR_STATE);

    p = PRIVATE_DSO(s);
    sa_return_val_if_fail(p->driver_wait, SA_ERROR_STATE);

    return p->driver_wait(s);
}

int driver_read(sa_stream *s, void *data, size_t nbytes) {
    struct private_dso *p;

    sa_return_val_if_fail(s, SA_ERROR_INVALID);
    sa_return_val_if_fail(s->private_dso, SA_ERROR_STATE);

    p = PRIVATE_DSO(s);
    sa_return_val_if_fail(p->driver_read, SA_ERROR_STATE);

    return p->driver_read(s, data, nbytes);
}

int driver_read_ni(sa_stream *s, unsigned channel, void *data, size_t nbytes) {
    struct private_dso *p;

    sa_return_val_if_fail(s, SA_ERROR_INVALID);
    sa_return_val_if_fail(s->private_dso, SA_ERROR_STATE);

    p = PRIVATE_DSO(s);
    sa_return_val_if_fail(p->driver_read_ni, SA_ERROR_STATE);

    return p->driver_read_ni(s, channel, data, nbytes);
}

int driver_pwrite(sa_stream *s, const void *data, size_t nbytes, int64_t offset, sa_seek_t whence) {
    struct private_dso *p;

    sa_return_val_if_fail(s, SA_ERROR_INVALID);
    sa_return_val_if_fail(s->private_dso, SA_ERROR_STATE);

    p = PRIVATE_DSO(s);
    sa_return_val_if_fail(p->driver_pwrite, SA_ERROR_STATE);

    return p->driver_pwrite(s, data, nbytes, offset, whence);
}

int driver_pwrite_ni(sa_stream *s, unsigned channel, const void *data, size_t nbytes, int64_t offset, sa_seek_t whence) {
    struct private_dso *p;

    sa_return_val_if_fail(s, SA_ERROR_INVALID);
    sa_return_val_if_fail(s->private_dso, SA_ERROR_STATE);

    p = PRIVATE_DSO(s);
    sa_return_val_if_fail(p->driver_pwrite_ni, SA_ERROR_STATE);

    return p->driver_pwrite_ni(s, channel, data, nbytes, offset, whence);
}

int driver_get_read_size(sa_stream *s, size_t *size) {
    struct private_dso *p;

    sa_return_val_if_fail(s, SA_ERROR_INVALID);
    sa_return_val_if_fail(s->private_dso, SA_ERROR_STATE);

    p = PRIVATE_DSO(s);
    sa_return_val_if_fail(p->driver_get_read_size, SA_ERROR_STATE);

    return p->driver_get_read_size(s, size);
}

int driver_get_write_size(sa_stream *s, size_t *size) {
    struct private_dso *p;

    sa_return_val_if_fail(s, SA_ERROR_INVALID);
    sa_return_val_if_fail(s->private_dso, SA_ERROR_STATE);

    p = PRIVATE_DSO(s);
    sa_return_val_if_fail(p->driver_get_write_size, SA_ERROR_STATE);

    return p->driver_get_write_size(s, size);
}

int driver_resume(sa_stream *s) {
    struct private_dso *p;

    sa_return_val_if_fail(s, SA_ERROR_INVALID);
    sa_return_val_if_fail(s->private_dso, SA_ERROR_STATE);

    p = PRIVATE_DSO(s);
    sa_return_val_if_fail(p->driver_resume, SA_ERROR_STATE);

    return p->driver_resume(s);
}

int driver_pause(sa_stream *s) {
    struct private_dso *p;

    sa_return_val_if_fail(s, SA_ERROR_INVALID);
    sa_return_val_if_fail(s->private_dso, SA_ERROR_STATE);

    p = PRIVATE_DSO(s);
    sa_return_val_if_fail(p->driver_pause, SA_ERROR_STATE);

    return p->driver_pause(s);
}

int driver_drain(sa_stream *s) {
    struct private_dso *p;

    sa_return_val_if_fail(s, SA_ERROR_INVALID);
    sa_return_val_if_fail(s->private_dso, SA_ERROR_STATE);

    p = PRIVATE_DSO(s);
    sa_return_val_if_fail(p->driver_drain, SA_ERROR_STATE);

    return p->driver_drain(s);
}