/* Spa
 * Copyright (C) 2017 Wim Taymans <wim.taymans@gmail.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>

#include <spa/type-map.h>
#include <spa/type-map-impl.h>
#include <spa/log.h>
#include <spa/node.h>
#include <spa/loop.h>
#include <spa/video/format-utils.h>
#include <spa/format-builder.h>

#include <lib/debug.h>

#if 0
/*
* JSON based format description

 [ <type>,
   [ <media-type>, <media-subtype> ],
   {
     <key> : [ <type>, <value>, [ <value>, ... ] ],
     ...
   }
 ]

   <type> = "123.."

   1: s = string    :  "value"
      i = int       :  <number>
      f = float     :  <float>
      b = bool      :  true | false
      R = rectangle : [ <width>, <height> ]
      F = fraction  : [ <num>, <denom> ]

   2: - = default (only default value present)
      e = enum	        : [ <value>, ... ]
      f = flags	        : [ <number> ]
      r = min/max	: [ <min>, <max> ]
      s = min/max/step  : [ <min>, <max>, <step> ]

   3: u = unset		: value is unset, choose from options or default
      o = optional	: value does not need to be set
      r = readonly      : value is read only
      d = deprecated    : value is deprecated

[ "Format",
  [ "video", "raw"],
  {
    "format" :    [ "se", "I420", [ "I420", "YUY2" ] ],
    "size" :      [ "Rru", [320, 240], [[ 640, 480], [1024,786]]],
    "framerate" : [ "Fsu", [25, 1], [[ 0, 1], [65536,1]]]"
  }
]

[ "Format",
  [ "audio", "raw"],
  {
    "format" :      [ "se", "S16LE", [ "F32LE", "S16LE" ] ],
    "rate" :        [ "iru", 44100, [8000, 96000]],
    "channels" :    [ "iru", 1, [1, 4096]]"
    "interleaved" : [ "beo", true ]"
  }
]
*/
#endif

#include <stddef.h>

struct spa_json_iter {
  const char *cur;
  const char *end;
  struct spa_json_iter *parent;
  int state;
  int depth;
};

#define NONE      0
#define STRUCT    1
#define BARE      2
#define STRING    3
#define UTF8      4
#define ESC       5

static void
spa_json_iter_init (struct spa_json_iter *iter, const char *data, size_t size)
{
  iter->end = data + size;
  iter->parent = NULL;
  iter->cur = data;
  iter->state = NONE;
}

struct spa_json_chunk {
	const char *value;
	int len;
};

enum spa_json_type {
	SPA_JSON_TYPE_INVALID,
	SPA_JSON_TYPE_ARRAY,
	SPA_JSON_TYPE_OBJECT,
	SPA_JSON_TYPE_STRING,
	SPA_JSON_TYPE_NUMBER,
	SPA_JSON_TYPE_BOOL,
	SPA_JSON_TYPE_NULL,
};

static inline enum spa_json_type spa_json_chunk_get_type(struct spa_json_chunk *chunk)
{
	switch (chunk->value[0]) {
	case '[':
		return SPA_JSON_TYPE_ARRAY;
	case '{':
		return SPA_JSON_TYPE_OBJECT;
	case '"':
		return SPA_JSON_TYPE_STRING;
	case '-': case '0' ... '9':
		return SPA_JSON_TYPE_NUMBER;
	case 't': case 'f':
		return SPA_JSON_TYPE_BOOL;
	case 'n':
		return SPA_JSON_TYPE_NULL;
	}
	return SPA_JSON_TYPE_INVALID;
}


static inline bool spa_json_chunk_is_object(struct spa_json_chunk *chunk) {
	return chunk->value[0] == '{';
}

static inline bool spa_json_chunk_is_array(struct spa_json_chunk *chunk) {
	return chunk->value[0] == '[';
}

static inline bool spa_json_chunk_is_string(struct spa_json_chunk *chunk) {
	return chunk->value[0] == '"';
}

static inline bool spa_json_chunk_is_number(struct spa_json_chunk *chunk) {
	return (chunk->value[0] >= '0' && chunk->value[0] <= '9') ||
		chunk->value[0] == '-' ;
}

static inline bool spa_json_chunk_is_bool(struct spa_json_chunk *chunk) {
	return chunk->value[0] == 't' || chunk->value[0] == 'f';
}

static inline bool spa_json_chunk_is_null(struct spa_json_chunk *chunk) {
	return chunk->value[0] == 'n';
}

static int
spa_json_iter_value(struct spa_json_iter *iter, struct spa_json_chunk *value)
{
  int utf8_remain = 0;

  for (;iter->cur < iter->end; iter->cur++) {
    unsigned char cur = (unsigned char) *iter->cur;
again:
    switch (iter->state) {
      case NONE:
        iter->state = STRUCT;
        iter->depth = 0;
        goto again;
      case STRUCT:
        switch (cur) {
          case '\t': case ' ': case '\r': case '\n': case ':': case ',':
            continue;
          case '"':
            value->value = iter->cur;
            iter->state = STRING;
            continue;
          case '[': case '{':
            value->value = iter->cur;
            if (++iter->depth > 1)
              continue;
            iter->cur++;
            return value->len = 1;
          case '}': case ']':
            if (iter->depth == 0) {
              if (iter->parent)
                iter->parent->cur = iter->cur;
              return -1;
            }
            --iter->depth;
            continue;
          case '-': case 'a' ... 'z': case 'A' ... 'Z': case '0' ... '9':
            value->value = iter->cur;
            iter->state = BARE;
            continue;
        }
        return -2;
      case BARE:
        switch (cur) {
          case '\t': case ' ': case '\r': case '\n': case ':': case ',':
          case ']': case '}':
            iter->state = STRUCT;
            if (iter->depth > 0)
              goto again;
            return value->len = iter->cur - value->value;
          default:
            if (cur >= 32 && cur <= 126)
              continue;
        }
        return -2;
      case STRING:
        switch (cur) {
          case '\\':
            iter->state = ESC;
            continue;
          case '"':
            iter->state = STRUCT;
            if (iter->depth > 0)
              continue;
            iter->cur++;
            return value->len = iter->cur - value->value;
          case 240 ... 247:
            utf8_remain++;
          case 224 ... 239:
            utf8_remain++;
          case 192 ... 223:
            utf8_remain++;
            iter->state = UTF8;
            continue;
          default:
            if (cur >= 32 && cur <= 126)
              continue;
        }
        return -2;
      case UTF8:
        switch (cur) {
          case 128 ... 191:
            if (--utf8_remain == 0)
              iter->state = STRING;
            continue;
        }
        return -2;
      case ESC:
        switch (cur) {
          case '"': case '\\': case '/': case 'b': case 'f': case 'n': case 'r':
          case 't': case 'u':
            iter->state = STRING;
            continue;
        }
        return -2;
    }
  }
  return iter->depth == 0 ? -1 : -2;
}

static int
spa_json_iter_enter(struct spa_json_iter *iter, struct spa_json_iter *sub)
{
  sub->end = iter->end;
  sub->parent = iter;
  sub->cur = iter->cur;
  sub->state = NONE;
  return 0;
}

static int
spa_json_iter_enter_array(struct spa_json_iter *iter,
			  struct spa_json_iter *array)
{
	struct spa_json_chunk chunk;
	if (spa_json_iter_value(iter, &chunk) < 0) return -1;
	if (*chunk.value != '[') return -1;
	return spa_json_iter_enter(iter, array);
}

static int
spa_json_iter_enter_object(struct spa_json_iter *iter,
			   struct spa_json_iter *object)
{
	struct spa_json_chunk chunk;
	if (spa_json_iter_value(iter, &chunk) < 0) return -1;
	if (*chunk.value != '{') return -1;
	return spa_json_iter_enter(iter, object);
}

static int
spa_json_iter_string(struct spa_json_iter *iter,
		     struct spa_json_chunk *str)
{
	if (spa_json_iter_value(iter, str) < 0) return -1;
	return (*str->value == '"')  ? 0 : -1;
}

static int
spa_format_parse(struct spa_json_iter *iter,
		 struct spa_json_chunk *media_type,
		 struct spa_json_chunk *media_subtype,
		 struct spa_json_iter *props)
{
	struct spa_json_iter it[2];
	struct spa_json_chunk type;

	if (spa_json_iter_enter_array(iter, &it[0]) < 0) return -1;
	if (spa_json_iter_string(&it[0], &type) < 0) return -1;
	if (strncmp(type.value, "\"Format\"", type.len) != 0) return -1;

	if (spa_json_iter_enter_array(&it[0], &it[1]) < 0) return -1;
	if (spa_json_iter_string(&it[1], media_type) < 0) return -1;
	if (spa_json_iter_string(&it[1], media_subtype) < 0) return -1;

	return spa_json_iter_enter_object(&it[0], props);
}

static int test_parsing(const char *format)
{
	struct spa_json_iter iter[5];
	struct spa_json_chunk media_type, media_subtype, value;
	struct spa_json_iter props;

	spa_json_iter_init (&iter[0], format, strlen(format));

	if (spa_format_parse(&iter[0], &media_type, &media_subtype, &props) < 0)
		return -1;

	printf("Media Type: %.*s\n", media_type.len, media_type.value);
	printf("Media SubType: %.*s\n", media_subtype.len, media_subtype.value);

	while (spa_json_iter_string(&props, &value) >= 0) {
		printf("Key: %.*s\n", value.len, value.value);

		if (spa_json_iter_enter_array(&props, &iter[1]) < 0) return -1;
		if (spa_json_iter_string(&iter[1], &value) < 0) return -1;
		printf("flags: %.*s\n", value.len, value.value);

		if (spa_json_iter_value(&iter[1], &value) < 0) return -1;
		printf("default: %.*s\n", value.len, value.value);

		if (spa_json_iter_enter_array(&iter[1], &iter[2]) < 0) return -1;
		while (spa_json_iter_value(&iter[2], &value) >= 0) {
			printf("value: %.*s\n", value.len, value.value);
		}
	}
	return 0;
}

int main(int argc, char *argv[])
{
	const char *format =
		"[ \"Format\", "
		"  [ \"audio\", \"raw\"], "
		"  { "
		"    \"format\":      [ \"se\", \"S16LE\", [ \"F32LE\", \"S16LE\" ]], "
		"    \"rate\":        [ \"iru\", 44100, [8000, 96000]],"
		"    \"channels\":    [ \"iru\", 1, [1, 4096]]"
		"    \"interleaved\": [ \"beo\", true ]"
		"  }"
		"]";

	test_parsing(format);

	return 0;
}