#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <errno.h>
#include <zsv.h>
#include <zsv/utils/prop.h>
#include <zsv/utils/cache.h>
#include <zsv/utils/file.h>
#include <zsv/utils/overwrite.h>
#include <yajl_helper/yajl_helper.h>

#ifndef ZSVTLS
#ifndef NO_THREADING
#define ZSVTLS _Thread_local
#else
#define ZSVTLS
#endif
#endif
// see arg.c

static struct zsv_prop_handler *zsv_with_default_custom_prop_handler(char mode) {
  ZSVTLS static char zsv_default_custom_prop_initd = 0;
  ZSVTLS static struct zsv_prop_handler zsv_default_custom_prop_handler = {0};

  switch (mode) {
  case 'c': // clear
    memset(&zsv_default_custom_prop_handler, 0, sizeof(zsv_default_custom_prop_handler));
    zsv_default_custom_prop_initd = 0;
    break;
  case 'g': // get
    if (!zsv_default_custom_prop_initd) {
      zsv_default_custom_prop_initd = 1;
      zsv_default_custom_prop_handler.handler = NULL;
      zsv_default_custom_prop_handler.ctx = NULL;
    }
    break;
  }
  return &zsv_default_custom_prop_handler;
}

ZSV_EXPORT
void zsv_clear_default_custom_prop_handler(void) {
  zsv_with_default_custom_prop_handler('c');
}

ZSV_EXPORT
struct zsv_prop_handler zsv_get_default_custom_prop_handler(void) {
  return *zsv_with_default_custom_prop_handler('g');
}

ZSV_EXPORT
void zsv_set_default_custom_prop_handler(struct zsv_prop_handler custom_prop_handler) {
  *zsv_with_default_custom_prop_handler(0) = custom_prop_handler;
}

// TO DO: import these through a proper header
static int zsv_properties_parse_process_value(yajl_helper_t yh, struct json_value *value);

struct zsv_properties_parser {
  yajl_helper_t yh;
  yajl_status stat;

  // queryable data
  struct zsv_file_properties *fp;
  struct zsv_opts *opts;
  struct zsv_prop_handler *custom_prop_handler;
  const unsigned char *filepath; // path to this properties file
};

const unsigned char *zsv_properties_parser_get_filepath(void *p_) {
  struct zsv_properties_parser *p = p_;
  return p ? p->filepath : NULL;
}

void *zsv_properties_parser_get_custom_ctx(void *p_) {
  struct zsv_properties_parser *p = p_;
  return p && p->custom_prop_handler ? p->custom_prop_handler->ctx : NULL;
}

struct zsv_opts *zsv_properties_parser_get_opts(void *p_) {
  struct zsv_properties_parser *p = p_;
  return p ? p->opts : NULL;
}

/**
 * Create a new properties parser
 */
struct zsv_properties_parser *zsv_properties_parser_new(const unsigned char *path,
                                                        struct zsv_prop_handler *custom_prop_handler,
                                                        struct zsv_file_properties *fp, struct zsv_opts *opts) {
  struct zsv_properties_parser *parser = calloc(1, sizeof(*parser));
  if (parser) {
    parser->yh = yajl_helper_new(32,
                                 NULL, // start_map,
                                 NULL, // end_map,
                                 NULL, // map_key,
                                 NULL, // start_array,
                                 NULL, // end_array,
                                 zsv_properties_parse_process_value, parser);
    if (!parser->yh)
      free(parser);
    else {
      parser->custom_prop_handler = custom_prop_handler;
      parser->fp = fp;
      parser->filepath = path;
      parser->opts = opts;
      parser->stat = yajl_status_ok;
      return parser;
    }
  }
  // error
  return NULL;
}

/**
 * Finished parsing
 */
enum zsv_status zsv_properties_parse_complete(struct zsv_properties_parser *parser) {
  if (parser && parser->stat == yajl_status_ok)
    parser->stat = yajl_complete_parse(yajl_helper_yajl(parser->yh));
  return parser && parser->stat == yajl_status_ok ? zsv_status_ok : zsv_status_error;
}

/**
 * Clean up
 */
enum zsv_status zsv_properties_parser_destroy(struct zsv_properties_parser *parser) {
  yajl_helper_delete(parser->yh);
  yajl_status stat = parser->stat;
  free(parser);
  return stat == yajl_status_ok ? zsv_status_ok : zsv_status_error;
}

/**
 * Load cached file properties into a zsp_opts and/or zsv_file_properties struct
 *
 * @param data_filepath            required file path
 * @param opts (optional)          parser options to load. will be updated to reflect
 *                                 what is actually used
 * @param custom_prop_handler (optional) handler for custom properties
 * @return zsv_status_ok on success
 */
struct zsv_file_properties zsv_cache_load_props(const char *data_filepath, struct zsv_opts *opts,
                                                struct zsv_prop_handler *custom_prop_handler) {
  // we need some memory to save the parsed properties
  // if the caller did not provide that, use our own
  struct zsv_file_properties tmp = {0};
  if (!(data_filepath && *data_filepath))
    return tmp; // e.g. input = stdin

  struct zsv_file_properties *fp = &tmp;
  struct zsv_properties_parser *p = NULL;
  unsigned char *fn = zsv_cache_filepath((const unsigned char *)data_filepath, zsv_cache_type_property, 0, 0);
  if (!fn)
    tmp.stat = zsv_status_memory;
  else {
    FILE *f;
    int err;
    if (!zsv_file_readable((char *)fn, &err, &f)) {
      if (err != ENOENT) {
        perror((const char *)fn);
        tmp.stat = zsv_status_error;
      }
    } else {
      p = zsv_properties_parser_new(fn, custom_prop_handler, fp, opts);
      if (!p)
        tmp.stat = zsv_status_memory;
      else if (p->stat != yajl_status_ok)
        tmp.stat = zsv_status_error;
      else {
        unsigned char buff[1024];
        size_t bytes_read;
        while ((bytes_read = fread(buff, 1, sizeof(buff), f))) {
          if ((p->stat = yajl_parse(yajl_helper_yajl(p->yh), buff, bytes_read)) != yajl_status_ok) {
            tmp.stat = zsv_status_error;
            break;
          }
        }
        if (tmp.stat == zsv_status_ok)
          zsv_properties_parse_complete(p);
      }
      fclose(f);
    }
    free(fn);
  }

  if (tmp.stat == zsv_status_ok) {
    // warn if the loaded properties conflict with command-line options
    if (fp->skip_specified) {
      if (opts && opts->option_overrides.skip_head && opts->rows_to_ignore != fp->skip)
        fprintf(stderr, "Warning: file property 'skip-head' overridden by command option\n");
      else if (opts)
        opts->rows_to_ignore = fp->skip;
    }
    if (fp->header_span_specified) {
      if (opts && opts->option_overrides.header_row_span && opts->header_span != fp->header_span)
        fprintf(stderr, "Warning: file property 'header-row-span' overridden by command option\n");
      else if (opts)
        opts->header_span = fp->header_span;
    }
  }
  if (p && tmp.stat == zsv_status_ok && zsv_properties_parser_destroy(p) != zsv_status_ok)
    tmp.stat = zsv_status_error;
  return tmp;
}

static int zsv_properties_parse_process_value(yajl_helper_t yh, struct json_value *value) {
  struct zsv_properties_parser *parser = yajl_helper_ctx(yh);
  struct zsv_file_properties *fp = parser->fp;
  if (yajl_helper_level_raw(yh) == 1) {
    const char *prop_name = yajl_helper_get_map_key(yh, 0);
    unsigned int *target = NULL;
    if (!strcmp(prop_name, "skip-head")) {
      target = &fp->skip;
      fp->skip_specified = 1;
    } else if (!strcmp(prop_name, "header-row-span")) {
      target = &fp->header_span;
      fp->header_span_specified = 1;
    }

    if (!target) {
      int rc = 1;
      struct zsv_prop_handler *custom_prop_handler = parser->custom_prop_handler;
      if (custom_prop_handler && custom_prop_handler->handler)
        rc = custom_prop_handler->handler(parser, prop_name, value);
      if (rc) {
        fprintf(stderr, "Unrecognized property: %s\n", prop_name);
        fp->stat = zsv_status_error;
      }
    } else {
      int err = 0;
      long long i = json_value_long(value, &err);
      if (err || i < 0 || i > UINT_MAX) {
        fp->stat = zsv_status_error;
        fprintf(stderr, "Invalid %s property value: should be an integer between 0 and %u", prop_name, UINT_MAX);
      } else
        *target = (unsigned int)i;
    }
  }
  return 1;
}

/**
 * zsv_new_with_properties(): use in lieu of zsv_new() to also merge zsv options
 * with any saved properties (such as rows_to_ignore or header_span) for the
 * specified input file. In the event that saved properties conflict with a
 * command-line option, the command-line option "wins" (the property value is
 * ignored), but a warning is printed
 *
 * optional `struct zsv_file_properties` supports custom file property processing
 */
enum zsv_status zsv_new_with_properties(struct zsv_opts *opts, struct zsv_prop_handler *custom_prop_handler,
                                        const char *input_path, zsv_parser *handle_out) {
  *handle_out = NULL;
  if (input_path) {
    struct zsv_file_properties fp = zsv_cache_load_props(input_path, opts, custom_prop_handler);
    if (fp.stat != zsv_status_ok)
      return fp.stat;
  }
#ifdef ZSV_EXTRAS
  if (opts->overwrite_auto)
    zsv_overwrite_auto(opts, input_path);
#endif
  if ((*handle_out = zsv_new(opts)))
    return zsv_status_ok;
  return zsv_status_memory;
}