#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "topic.h"
#include "helpgen.h"

static void dumpstring(FILE *f, const char *s, int multiline) {
  int column = 0;
  unsigned char ch;

  while (*s) {
    if (column == 0) {
      if (multiline) fprintf(f, "  ");
      fprintf(f, "\"");
    }
    ch = *s++;

    if (ch >= 32 && ch < 127 && ch != '"' && ch != '\\') {
      fprintf(f, "%c", ch);
      column++;
    }
    else if (ch == '\n') {
      fprintf(f, "\\n");
      column += 2;
    }
    else {
      assert(ch != '\r');
      fprintf(f, "\\%03o", ch);
      column += 4;
    }

    if (multiline && column > 72) {
      fprintf(f, "\"\n");
      column = 0;
    }
  }

  if (column) {
    fprintf(f, "\"");
    if (multiline) fprintf(f, "\n");
  }
}

static void fcout(FILE *f, struct topic **topics, int ntopics) {
  int i, j, n;
  unsigned numentries = 0;

  fprintf(f, "/* Automatically generated - do not edit */\n\n");

  fprintf(f, "struct HelpTopic {\n");
  fprintf(f, "  const char *title;\n");
  fprintf(f, "  const char *body;\n");
  fprintf(f, "};\n\n");


  for (i=0; i<ntopics; i++) {
    struct topic *t = topics[i];
    const char *title = topic_gettitle(t, 0);
    const char *body = topic_getbody(t); 

    if (!body) body = "";

    fprintf(f, "static const char body_%d[] = \n", i);
    dumpstring(f, body, 1 /* multiline */);
    fprintf(f, ";\n");

    fprintf(f, "static const HelpTopic topic_%d = \n  { ", i);
    dumpstring(f, title, 0 /* not multiline */);
    fprintf(f, ", body_%d };\n\n", i);
  }


  fprintf(f, "static const char *topiclist[] = {\n");
  for (i=0; i<ntopics; i++) {
    struct topic *t = topics[i];
    const char *title = topic_gettitle(t, 0);

    fprintf(f, "  ");
    dumpstring(f, title, 0 /* not multiline */);
    fprintf(f, ",\n");
  }
  fprintf(f, "};\n");
  fprintf(f, "static const unsigned numtopiclist = %d;\n\n", ntopics);


  fprintf(f, "struct helpentry {\n");
  fprintf(f, "  const char *topic;\n");
  fprintf(f, "  const HelpTopic *data;\n");
  fprintf(f, "};\n\n");

  fprintf(f, "static helpentry helptable[] = {\n");
  for (i=0; i<ntopics; i++) {
    struct topic *t = topics[i];

    n = topic_getnumtitles(t);
    for (j=0; j<n; j++) {
      fprintf(f, "{ ");
      dumpstring(f, topic_gettitle(t, j), 0 /* not multiline */);
      fprintf(f, ", &topic_%d },\n", i);
      numentries++;
    }
  }
  fprintf(f, "};\n");
  fprintf(f, "static const unsigned helptablenum = %u;\n\n", numentries);
}

void cout(const char *file, struct topic **topics, int ntopics) {
  FILE *f;

  f = fopen(file, "w");
  if (!f) {
    fprintf(stderr, "%s: fopen failed", file);
    exit(1);
  }

  fcout(f, topics, ntopics);

  if (ferror(f)) {
    fprintf(stderr, "%s: write error", file);
    exit(1);
  }
  if (fclose(f)) {
    fprintf(stderr, "%s: fclose failed", file);
    exit(1);
  }
}