/*
  Copyright 2011-2021 David Robillard <d@drobilla.net>

  Permission to use, copy, modify, and/or distribute this software for any
  purpose with or without fee is hereby granted, provided that the above
  copyright notice and this permission notice appear in all copies.

  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/

#include "console.h"

#include "serd/serd.h"

#include <errno.h>
#include <limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define SERDI_ERROR(msg) fprintf(stderr, "serdi: " msg)
#define SERDI_ERRORF(fmt, ...) fprintf(stderr, "serdi: " fmt, __VA_ARGS__)

typedef struct {
  SerdNode* s;
  SerdNode* p;
  SerdNode* o;
  SerdNode* g;
} FilterPattern;

static int
print_usage(const char* const name, const bool error)
{
  static const char* const description =
    "Read and write RDF syntax.\n"
    "Use - for INPUT to read from standard input.\n\n"
    "  -C           Convert literals to canonical form.\n"
    "  -F PATTERN   Filter out statements that match PATTERN.\n"
    "  -G PATTERN   Only include statements matching PATTERN.\n"
    "  -I BASE_URI  Input base URI.\n"
    "  -b BYTES     I/O block size.\n"
    "  -c PREFIX    Chop PREFIX from matching blank node IDs.\n"
    "  -f           Fast and loose mode (possibly ugly output).\n"
    "  -h           Display this help and exit.\n"
    "  -i SYNTAX    Input syntax (turtle/ntriples/trig/nquads),\n"
    "               or flag (lax/variables/verbatim).\n"
    "  -k BYTES     Parser stack size.\n"
    "  -m           Build a model in memory before writing.\n"
    "  -o SYNTAX    Output syntax (empty/turtle/ntriples/nquads),\n"
    "               or flag (ascii/expanded/verbatim/terse/lax).\n"
    "  -p PREFIX    Add PREFIX to blank node IDs.\n"
    "  -q           Suppress all output except data.\n"
    "  -r ROOT_URI  Keep relative URIs within ROOT_URI.\n"
    "  -s STRING    Parse STRING as input.\n"
    "  -v           Display version information and exit.\n"
    "  -w FILENAME  Write output to FILENAME instead of stdout.\n";

  FILE* const os = error ? stderr : stdout;
  fprintf(os, "%s", error ? "\n" : "");
  fprintf(os, "Usage: %s [OPTION]... INPUT...\n", name);
  fprintf(os, "%s", description);
  return error ? 1 : 0;
}

static int
missing_arg(const char* const name, const char opt)
{
  SERDI_ERRORF("option requires an argument -- '%c'\n", opt);
  return print_usage(name, true);
}

static SerdStatus
on_filter_event(void* const handle, const SerdEvent* const event)
{
  if (event->type == SERD_STATEMENT) {
    FilterPattern* const pat = (FilterPattern*)handle;
    if (pat->s) {
      return SERD_ERR_INVALID;
    }

    const SerdStatement* const statement = event->statement.statement;
    pat->s = serd_node_copy(serd_statement_subject(statement));
    pat->p = serd_node_copy(serd_statement_predicate(statement));
    pat->o = serd_node_copy(serd_statement_object(statement));
    pat->g = serd_node_copy(serd_statement_graph(statement));
  }

  return SERD_SUCCESS;
}

static SerdSink*
parse_filter(SerdWorld* const      world,
             const SerdSink* const sink,
             const char* const     str,
             const bool            inclusive)
{
  SerdEnv* const  env         = serd_env_new(SERD_EMPTY_STRING());
  FilterPattern   pat         = {NULL, NULL, NULL, NULL};
  SerdSink*       in_sink     = serd_sink_new(&pat, on_filter_event, NULL);
  SerdByteSource* byte_source = serd_byte_source_new_string(str, NULL);
  SerdReader*     reader      = serd_reader_new(
    world, SERD_NQUADS, SERD_READ_VARIABLES, env, in_sink, 4096);

  SerdStatus st = serd_reader_start(reader, byte_source);
  if (!st) {
    st = serd_reader_read_document(reader);
  }

  serd_reader_free(reader);
  serd_env_free(env);
  serd_byte_source_free(byte_source);
  serd_sink_free(in_sink);

  if (st) {
    return NULL;
  }

  SerdSink* filter =
    serd_filter_new(sink, pat.s, pat.p, pat.o, pat.g, inclusive);

  serd_node_free(pat.s);
  serd_node_free(pat.p);
  serd_node_free(pat.o);
  serd_node_free(pat.g);
  return filter;
}

static SerdStatus
read_file(SerdWorld* const      world,
          SerdSyntax            syntax,
          const SerdReaderFlags flags,
          SerdEnv* const        env,
          const SerdSink* const sink,
          const size_t          stack_size,
          const char* const     filename,
          const char* const     add_prefix,
          const size_t          block_size)
{
  syntax = syntax ? syntax : serd_guess_syntax(filename);
  syntax = syntax ? syntax : SERD_TRIG;

  SerdByteSource* byte_source = serd_open_input(filename, block_size);

  if (!byte_source) {
    SERDI_ERRORF(
      "failed to open input file `%s' (%s)\n", filename, strerror(errno));

    return SERD_ERR_UNKNOWN;
  }

  SerdReader* reader =
    serd_reader_new(world, syntax, flags, env, sink, stack_size);

  serd_reader_add_blank_prefix(reader, add_prefix);

  SerdStatus st = serd_reader_start(reader, byte_source);

  st = st ? st : serd_reader_read_document(reader);

  serd_reader_free(reader);
  serd_byte_source_free(byte_source);

  return st;
}

int
main(int argc, char** argv)
{
  const char* const prog = argv[0];

  SerdNode*       base          = NULL;
  SerdSyntax      input_syntax  = SERD_SYNTAX_EMPTY;
  SerdSyntax      output_syntax = SERD_SYNTAX_EMPTY;
  SerdReaderFlags reader_flags  = 0;
  SerdWriterFlags writer_flags  = 0;
  bool            no_inline     = false;
  bool            osyntax_set   = false;
  bool            use_model     = false;
  bool            canonical     = false;
  bool            quiet         = false;
  size_t          block_size    = 4096u;
  size_t          stack_size    = 4194304;
  const char*     input_string  = NULL;
  const char*     in_pattern    = NULL;
  const char*     out_pattern   = NULL;
  const char*     add_prefix    = "";
  const char*     chop_prefix   = NULL;
  const char*     root_uri      = NULL;
  const char*     out_filename  = NULL;
  int             a             = 1;
  for (; a < argc && argv[a][0] == '-'; ++a) {
    if (argv[a][1] == '\0') {
      break;
    }

    for (int o = 1; argv[a][o]; ++o) {
      const char opt = argv[a][o];

      if (opt == 'C') {
        canonical = true;
      } else if (opt == 'f') {
        no_inline = true;
        writer_flags |= (SERD_WRITE_EXPANDED | SERD_WRITE_VERBATIM);
      } else if (opt == 'h') {
        return print_usage(prog, false);
      } else if (argv[a][1] == 'm') {
        use_model = true;
      } else if (opt == 'q') {
        quiet = true;
      } else if (opt == 'v') {
        return serd_print_version(argv[0]);
      } else if (argv[a][1] == 'F') {
        if (++a == argc) {
          return missing_arg(argv[0], 'F');
        }

        out_pattern = argv[a];
        break;
      } else if (argv[a][1] == 'G') {
        if (++a == argc) {
          return missing_arg(argv[0], 'g');
        }

        in_pattern = argv[a];
        break;
      } else if (argv[a][1] == 'I') {
        if (++a == argc) {
          return missing_arg(prog, 'I');
        }

        base = serd_new_uri(SERD_STRING(argv[a]));
        break;
      } else if (opt == 'b') {
        if (argv[a][o + 1] || ++a == argc) {
          return missing_arg(prog, 'b');
        }

        char*      endptr = NULL;
        const long size   = strtol(argv[a], &endptr, 10);
        if (size < 1 || size == LONG_MAX || *endptr != '\0') {
          SERDI_ERRORF("invalid block size `%s'\n", argv[a]);
          return 1;
        }
        block_size = (size_t)size;
        break;
      } else if (opt == 'c') {
        if (argv[a][o + 1] || ++a == argc) {
          return missing_arg(prog, 'c');
        }

        chop_prefix = argv[a];
        break;
      } else if (opt == 'i') {
        if (argv[a][o + 1] || ++a == argc) {
          return missing_arg(prog, 'i');
        }

        if (serd_set_input_option(
              SERD_STRING(argv[a]), &input_syntax, &reader_flags)) {
          return print_usage(argv[0], true);
        }
        break;
      } else if (opt == 'k') {
        if (argv[a][o + 1] || ++a == argc) {
          return missing_arg(prog, 'k');
        }

        char*      endptr = NULL;
        const long size   = strtol(argv[a], &endptr, 10);
        if (size <= 0 || size == LONG_MAX || *endptr != '\0') {
          SERDI_ERRORF("invalid stack size `%s'\n", argv[a]);
          return 1;
        }
        stack_size = (size_t)size;
        break;
      } else if (opt == 'o') {
        if (argv[a][o + 1] || ++a == argc) {
          return missing_arg(prog, 'o');
        }

        if (serd_set_output_option(
              SERD_STRING(argv[a]), &output_syntax, &writer_flags)) {
          return print_usage(argv[0], true);
        }

        osyntax_set =
          output_syntax != SERD_SYNTAX_EMPTY || !strcmp(argv[a], "empty");

        break;
      } else if (opt == 'p') {
        if (argv[a][o + 1] || ++a == argc) {
          return missing_arg(prog, 'p');
        }

        add_prefix = argv[a];
        break;
      } else if (opt == 'r') {
        if (argv[a][o + 1] || ++a == argc) {
          return missing_arg(prog, 'r');
        }

        root_uri = argv[a];
        break;
      } else if (opt == 's') {
        if (argv[a][o + 1] || ++a == argc) {
          return missing_arg(prog, 's');
        }

        input_string = argv[a];
        break;
      } else if (opt == 'w') {
        if (argv[a][o + 1] || ++a == argc) {
          return missing_arg(argv[0], 'w');
        }

        out_filename = argv[a];
        break;
      } else {
        SERDI_ERRORF("invalid option -- '%s'\n", argv[a] + 1);
        return print_usage(prog, true);
      }
    }
  }

  if (in_pattern && out_pattern) {
    SERDI_ERROR("only one of -F and -G can be given at once\n");
    return 1;
  }

  if (a == argc && !input_string) {
    SERDI_ERROR("missing input\n");
    return print_usage(prog, true);
  }

  char* const* const inputs   = argv + a;
  const int          n_inputs = argc - a;

  bool input_has_graphs = serd_syntax_has_graphs(input_syntax);
  for (int i = a; i < argc; ++i) {
    if (serd_syntax_has_graphs(serd_guess_syntax(argv[i]))) {
      input_has_graphs = true;
      break;
    }
  }

  if (!output_syntax && !osyntax_set) {
    output_syntax = input_has_graphs ? SERD_NQUADS : SERD_NTRIPLES;
  }

  if (!base && n_inputs == 1 &&
      (output_syntax == SERD_NQUADS || output_syntax == SERD_NTRIPLES)) {
    // Choose base URI from the single input path
    char* const input_path = serd_canonical_path(inputs[0]);
    if (!input_path || !(base = serd_new_file_uri(SERD_STRING(input_path),
                                                  SERD_EMPTY_STRING()))) {
      SERDI_ERRORF("unable to determine base URI from path %s\n", inputs[0]);
    }
    serd_free(input_path);
  }

  SerdWorld* const world = serd_world_new();
  SerdEnv* const   env =
    serd_env_new(base ? serd_node_string_view(base) : SERD_EMPTY_STRING());

  serd_set_stream_utf8_mode(stdin);
  if (!out_filename) {
    serd_set_stream_utf8_mode(stdout);
  }

  const SerdDescribeFlags describe_flags =
    no_inline ? SERD_NO_INLINE_OBJECTS : 0u;

  SerdByteSink* const byte_sink = serd_open_output(out_filename, block_size);
  if (!byte_sink) {
    perror("serdi: error opening output file");
    return 1;
  }

  SerdWriter* const writer =
    serd_writer_new(world, output_syntax, writer_flags, env, byte_sink);

  SerdModel*      model    = NULL;
  SerdSink*       inserter = NULL;
  const SerdSink* out_sink = NULL;
  if (use_model) {
    const SerdModelFlags flags = (input_has_graphs ? SERD_STORE_GRAPHS : 0u);

    model = serd_model_new(world, SERD_ORDER_SPO, flags);
    if (input_has_graphs) {
      serd_model_add_index(model, SERD_ORDER_GSPO);
    }

    if (!no_inline) {
      serd_model_add_index(model, SERD_ORDER_OPS);
      if (input_has_graphs) {
        serd_model_add_index(model, SERD_ORDER_GOPS);
      }
    }

    inserter = serd_inserter_new(model, NULL);
    out_sink = inserter;
  } else {
    out_sink = serd_writer_sink(writer);
  }

  const SerdSink* sink = out_sink;

  SerdSink* canon = NULL;
  if (canonical) {
    sink = canon = serd_canon_new(world, out_sink, reader_flags);
  }

  SerdSink* filter = NULL;
  if (in_pattern) {
    if (!(filter = parse_filter(world, sink, in_pattern, true))) {
      SERDI_ERROR("error parsing inclusive filter pattern\n");
      return EXIT_FAILURE;
    }

    sink = filter;
  } else if (out_pattern) {
    if (!(filter = parse_filter(world, sink, out_pattern, false))) {
      SERDI_ERROR("error parsing exclusive filter pattern\n");
      return EXIT_FAILURE;
    }

    sink = filter;
  }

  if (quiet) {
    serd_set_log_func(world, serd_quiet_log_func, NULL);
  }

  if (root_uri) {
    serd_writer_set_root_uri(writer, SERD_STRING(root_uri));
  }

  serd_writer_chop_blank_prefix(writer, chop_prefix);

  SerdStatus st = SERD_SUCCESS;
  if (input_string) {
    SerdByteSource* const byte_source =
      serd_byte_source_new_string(input_string, NULL);

    SerdReader* const reader =
      serd_reader_new(world,
                      input_syntax ? input_syntax : SERD_TRIG,
                      reader_flags,
                      env,
                      sink,
                      stack_size);

    serd_reader_add_blank_prefix(reader, add_prefix);

    if (!(st = serd_reader_start(reader, byte_source))) {
      st = serd_reader_read_document(reader);
    }

    serd_reader_free(reader);
    serd_byte_source_free(byte_source);
  }

  size_t prefix_len = 0;
  char*  prefix     = NULL;
  if (n_inputs > 1) {
    prefix_len = 8 + strlen(add_prefix);
    prefix     = (char*)calloc(1, prefix_len);
  }

  for (int i = 0; !st && i < n_inputs; ++i) {
    if (!base && strcmp(inputs[i], "-")) {
      if ((st = serd_set_base_uri_from_path(env, inputs[i]))) {
        SERDI_ERRORF("failed to set base URI from path %s\n", inputs[i]);
        break;
      }
    }

    if (n_inputs > 1) {
      snprintf(prefix, prefix_len, "f%d%s", i, add_prefix);
    }

    if ((st = read_file(world,
                        input_syntax,
                        reader_flags,
                        env,
                        sink,
                        stack_size,
                        inputs[i],
                        n_inputs > 1 ? prefix : add_prefix,
                        block_size))) {
      break;
    }
  }
  free(prefix);

  if (st <= SERD_FAILURE && use_model) {
    const SerdSink* writer_sink = serd_writer_sink(writer);
    SerdCursor*     everything  = serd_model_begin_ordered(
      model, input_has_graphs ? SERD_ORDER_GSPO : SERD_ORDER_SPO);

    serd_env_write_prefixes(env, writer_sink);

    st = serd_describe_range(
      everything,
      writer_sink,
      describe_flags |
        ((output_syntax == SERD_NTRIPLES || output_syntax == SERD_NQUADS)
           ? SERD_NO_INLINE_OBJECTS
           : 0u));

    serd_cursor_free(everything);
  }

  serd_sink_free(canon);
  serd_sink_free(filter);
  serd_sink_free(inserter);
  serd_model_free(model);
  serd_writer_free(writer);
  serd_env_free(env);
  serd_node_free(base);
  serd_world_free(world);

  if (serd_byte_sink_close(byte_sink)) {
    perror("serdi: write error");
    st = SERD_ERR_UNKNOWN;
  }

  serd_byte_sink_free(byte_sink);

  return (st > SERD_FAILURE) ? 1 : 0;
}