#include <dirent.h>
#include <stdio.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <time.h>
/*
Copyright (c) 2021 Derek Stevens
Copyright (c) 2021 Devine Lu Linvega

Permission to use, copy, modify, and 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.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE.
*/

/* clang-format off */

#define NAME "nilFM"
#define DOMAIN "https://nilfm.cc"
#define DESC  "lair of drkste aka nilix: programmer, artist, philosopher"
#define ABOUT "Derek Stevens &lt;"\
              "<a href='mailto://nilix@nilfm.cc'>nilix@nilfm.cc</a>&gt;<br/>"\
              "artist, programmer, philosopher<br/><br/>"\
              "verify my signature: <a href='/serv/signingKey.pub'>signing public key</a><br/>"\
              "send me an encrypted message: <a href='/serv/encryptionKey.pub'>encryption public key</a>"
#define CONTACT "contact: <a href='mailto://nilix@nilfm.cc'>nilix@nilfm.cc</a> (<a href='keys.html'>keys</a>)<br/>"
#define FOOTER "<a href='/git/'><img "\
                "src='/img/git.svg' alt='visit the nilFM hack lab.'/></a>&nbsp;"\
                "<a rel='me' href='https://fosstodon.org/@nilix'><img "\
                "src='/img/mastodon.svg' alt='visit me on Mastodon.'/></a>&nbsp;"\
                "<a href='https://webring.xxiivv.com'><img "\
                "src='/img/webring.svg' alt='visit the Webring.'/></a><br/>"
#define LICENSE "<a rel='license' "\
                "href='https://creativecommons.org/licenses/by-nc/4.0/"\
                "legalcode.txt'>CC-BY-NC 4</a>"
#define SITEROOT "../www/"
#define MAINCSS "/new.css"
#define FRONTCSS "/front.css"

/* clang-format on */

struct dirent* dir;

typedef struct Lexicon {
  int len, refs[512];
  char files[512][64];
} Lexicon;

/* clang-format off */

char  clca(char c) { return c >= 'A' && c <= 'Z' ? c + ('a' - 'A') : c; } /* char to lowercase */
char  cuca(char c) { return c >= 'a' && c <= 'z' ? c - ('a' - 'A') : c; } /* char to uppercase */
int   slen(char *s) { int i = 0; while(s[i] && s[++i]) { ; } return i; } /* string length */
char *st__(char *s, char (*fn)(char)) { int i = 0; char c; while((c = s[i])) s[i++] = fn(c); return s; }
char *stuc(char *s) { return st__(s, cuca); } /* string to uppercase */
char *stlc(char *s) { return st__(s, clca); } /* string to lowercase */
char *scpy(char *src, char *dst, int len) { int i = 0; while((dst[i] = src[i]) && i < len - 2) i++; dst[i + 1] = '\0'; return dst; } /* string copy */
int   scmp(char *a, char *b) { int i = 0; while(a[i] == b[i]) if(!a[i++]) return 1; return 0; } /* string compare */
char *scsw(char *s, char a, char b) { int i = 0; char c; while((c = s[i])) s[i++] = c == a ? b : c; return s; } /* string char swap */
char *scat(char *dst, const char *src) { char *ptr = dst + slen(dst); while(*src) *ptr++ = *src++; *ptr = '\0'; return dst; } /* string cat */
int   ssin(char *s, char *ss) { int a = 0, b = 0; while(s[a]) { if(s[a] == ss[b]) { if(!ss[b + 1]) return a - b; b++; } else b = 0; a++; } return -1; } /* string substring index */
char *ccat(char *dst, char c) { int len = slen(dst); dst[len] = c; dst[len + 1] = '\0'; return dst; }
int clin(char *str, char c) {int i = -1; int j = 0; while(str[j] != '\0'){if(str[j] == c) i = j;j++;}return i;} /* find last occurence of character in string */
/* clang-format on */

int fpinject(FILE* f, Lexicon* l, char* filepath);

int error(char* msg, char* val) {
  printf("Error: %s(%s)\n", msg, val);
  return 0;
}

int ismetanav(char* name) { return scmp(name, "meta.nav"); }

int findf(Lexicon* l, char* f) {
  int i;
  char filename[64];
  scat(scsw(stlc(scpy(f, filename, 64)), ' ', '_'), ".htm");
  for (i = 0; i < l->len; ++i)
    if (scmp(l->files[i], filename))
      return i;
  return -1;
}

int gettwtxt(FILE* f) {
  char buf[1024] = {0};
  char line[256];
  char datebuf[16] = {0};
  char msgbuf[240] = {0};
  char *l, *d, *m;
  FILE* twtxt = fopen(SITEROOT "twtxt.txt", "r");

  scat(buf, "<div id='twtxtFeed'><h2>recent activity:</h2><table>");
  if (!twtxt) {
    error("Get twtxt feed", "no twtxt.txt");
    return 0;
  } else {
    int i = 0;
    while (fgets(line, 256, twtxt) && i < 3) {
      l = line;
      while (*l != 'T') {
        ccat(datebuf, *l++);
      }
      while (*l != '\t') {
        l++;
      }
      scat(msgbuf, l);
      scat(buf, "<tr><td style='white-space:nowrap;vertical-align: top;'>");
      scat(buf, datebuf);
      scat(buf, ":</td><td> ");
      scat(buf, msgbuf);
      scat(buf, "</td></tr>");
      d = datebuf;
      while (*d) {
        *d++ = 0;
      }
      m = msgbuf;
      while (*m) {
        *m++ = 0;
      }
      i++;
    }
    scat(buf, "</table><a href='/twtxt.txt'>see all</a>");
    scat(buf, "</div>");
    fputs(buf, f);
    return 1;
  }
}

void fpedited(FILE* f, char* path) {
  struct stat attr;
  stat(path, &attr);
  fprintf(f, "Edited on %s<br/>", ctime(&attr.st_mtime));
}

int fpportal(FILE* f, Lexicon* l, char* s, int head) {
  int target;
  char srcpath[64], filename[64];
  target = findf(l, s);
  if (target < 0)
    return error("Missing portal", s);
  srcpath[0] = 0;
  filename[0] = 0;
  scat(scat(scat(srcpath, "inc/"), scpy(s, filename, 64)), ".htm");
  if (head)
    fprintf(
      f,
      "<h3 id='%s'><a href='%s.html'>%s</a></h3>",
      scsw(filename, ' ', '_'),
      filename,
      s);
  fpinject(f, l, srcpath);
  l->refs[target]++;
  return 1;
}

int fphref(FILE* f, char* s) {
  char href[1024] = {0};
  char txt[1024] = {0};

  char* c = s;
  int i = 0;
  while (i < 2) {
    if (*c == '|' || !(*c)) {
      i++;
      c++;
      continue;
    }
    switch (i) {
      case 0:
        ccat(href, *c++);
        break;
      case 1:
        ccat(txt, *c++);
        break;
    }
  }
  fprintf(f, "<a href='%s'>%s</a>", href, txt);
  return 1;
}

char* thumbtrans(char* s, char* thumb) {
  int i, j;
  char* ss;
  char* fnss;
  char fn[1024];

  scpy(s, thumb, slen(s));

  i = clin(thumb, '/');
  ss = thumb + i + 1;

  scpy(ss, fn, slen(thumb) - i + 1);
  scpy(".thumb/", ss, 8);

  j = clin(fn, '.');
  fnss = fn + j;
  scpy(".png", fnss, 5);
  scat(thumb, fn);
  return thumb;
}

int fpimg(FILE* f, char* s) {
  char id[1024] = {0};
  char src[1024] = {0};
  char alt[1024] = {0};
  char thumb[1024] = {0};

  char* c = s;
  int i = 0;
  while (i < 3) {
    if (*c == '|' || !(*c)) {
      i++;
      c++;
      continue;
    }
    switch (i) {
      case 0:
        ccat(id, *c++);
        break;
      case 1:
        ccat(src, *c++);
        break;
      case 2:
        ccat(alt, *c++);
        break;
    }
  }

  thumbtrans(src, thumb);
  fprintf(f, "<a id='%s' href='%s'>\n", id, src);
  fprintf(f, "<img class='image' src='%s' alt='%s'/>\n", thumb, alt);
  fputs("</a>", f);
  return 1;
}

int fphimg(FILE* f, char* s) {
  char id[1024] = {0};
  char href[1024] = {0};
  char src[1024] = {0};
  char alt[1024] = {0};
  char thumb[1024] = {0};

  char* c = s;
  int i = 0;
  while (i < 4) {
    if (*c == '|' || !(*c)) {
      i++;
      c++;
      continue;
    }
    switch (i) {
      case 0:
        ccat(id, *c++);
        break;
      case 1:
        ccat(href, *c++);
        break;
      case 2:
        ccat(src, *c++);
        break;
      case 3:
        ccat(alt, *c++);
        break;
    }
  }

  thumbtrans(src, thumb);

  fprintf(f, "<a id='%s' href='%s'>\n", id, href);
  fprintf(f, "<img class='image' src='%s' alt='%s'/>\n", thumb, alt);
  fputs("</a>", f);
  return 1;
}

int fpaudio(FILE* f, char* s) {
  fputs("<audio class='player' preload='metadata' controls>", f);
  fprintf(f, "<source src='%s' type='audio/mpeg'>[HTML5 audio]", s);
  fputs("</audio>", f);
  return 1;
}

int fptemplate(FILE* f, Lexicon* l, char* s) {
  int target;
  if (s[0] == '/')
    return fpportal(f, l, s + 1, 1);
  if (s[0] == '*')
    return fphref(f, s + 1);
  if (s[0] == ':')
    return fpimg(f, s + 1);
  if (s[0] == '?')
    return fphimg(f, s + 1);
  if (s[0] == '_')
    return fpaudio(f, s + 1);
  target = findf(l, s);
  if (target < 0)
    return error("Missing link", s);
  fprintf(f, "<a href='%s.html' class='local'>", scsw(stlc(s), ' ', '_'));
  fprintf(f, "%s</a>", scsw(stlc(s), '_', ' '));
  l->refs[target]++;
  return 1;
}

int fpinject(FILE* f, Lexicon* l, char* filepath) {
  FILE* inc;
  char c, s[1024];
  unsigned char t = 0;
  scsw(filepath, ' ', '_');
  if (!(inc = fopen(filepath, "r")))
    return error("Missing include", filepath);
  s[0] = 0;
  while ((c = fgetc(inc)) != EOF) {
    if (c == '}') {
      t = 0;
      if (!fptemplate(f, l, s))
        return 0;
      continue;
    }
    if (c == '{') {
      s[0] = 0;
      t = 1;
      continue;
    }
    if (slen(s) > 1023)
      return error("Templating error", filepath);
    if (t)
      ccat(s, c);
    else
      fprintf(f, "%c", c);
  }
  fclose(inc);
  return 1;
}

int fpfooter(FILE* f, char* name, char* path) {
  if (!f || !name || !path)
    return 0;
  fputs("<footer>", f);
  if (!ismetanav(name)) {
    fpedited(f, path);
    fputs(CONTACT, f);
  }
  fputs(FOOTER, f);
  fputs(LICENSE, f);
  fputs("</footer>", f);
  return 1;
}

FILE* build(FILE* f, Lexicon* l, char* name, char* srcpath) {
  if (!f)
    return f;
  /* begin */
  fputs("<!DOCTYPE html><html lang='en'>", f);
  fputs("<head>", f);
  fprintf(
    f,
    "<meta charset='utf-8'>"
    "<meta name='description' content='%s'/>"
    "<meta name='viewport' content='width=device-width,initial-scale=1'>",
    DESC);
  if (ismetanav(name)) {
    fputs("<link rel='stylesheet' type='text/css' href='" FRONTCSS "'>", f);
  } else {
    fputs("<link rel='stylesheet' type='text/css' href='" MAINCSS "'>", f);
  }
  fprintf(
    f,
    "<link rel='shortcut icon' href='/favicon.ico'>"
    "<title>" NAME " &mdash; %s</title>",
    ismetanav(name) ? "home" : name);
  fputs("</head>", f);
  fputs("<body>", f);
  /* header */
  fputs("<header>", f);
  if (ismetanav(name)) {
    fputs("<h1>" NAME "</h1>", f);
  } else {
    fputs("<h1><a href='/'>" NAME "</a></h1>", f);
  }

  fputs("</header>", f);
  /* about (main page only) */
  if (ismetanav(name)) {
    fputs("<div id='about'>" ABOUT "</div>", f);
  }
  /* nav */
  fputs("<nav>", f);
  if (!fpportal(f, l, "meta.nav", 0))
    printf(">>> Building failed: %s\n", name);
  fputs("</nav>", f);
  /* main */
  if (!ismetanav(name)) {
    fputs("<main>\n\n", f);
    fprintf(f, "<h2>%s</h2>", name);
    if (!fpinject(f, l, srcpath))
      printf(">>> Building failed: %s\n", name);
    fputs("\n\n</main>", f);
  } else {
    gettwtxt(f);
  }
  /* footer */
  if (!fpfooter(f, name, srcpath)) {
    printf(">>> Building failed: footer(%s)\n", name);
  }

  /* end */
  fputs("</body></html>", f);
  return f;
}

int generate(Lexicon* l) {
  int i = 0;
  char srcpath[64], dstpath[64], filename[64];
  for (i = 0; i < l->len; ++i) {
    srcpath[0] = 0;
    dstpath[0] = 0;
    filename[0] = 0;
    /* src */
    scpy(l->files[i], filename, ssin(l->files[i], ".htm") + 1);
    scat(srcpath, "inc/");
    scat(srcpath, filename);
    scat(srcpath, ".htm");
    /* dst */
    if (scmp(filename, "meta.nav")) {
      scat(dstpath, SITEROOT);
      scat(dstpath, "index.html");
    } else {
      scat(dstpath, SITEROOT);
      scat(dstpath, filename);
      scat(dstpath, ".html");
    }
    fclose(build(fopen(dstpath, "w"), l, scsw(filename, '_', ' '), srcpath));
  }
  printf("Generated %d files\n", i);
  return 1;
}

int index(Lexicon* l, DIR* d) {
  while ((dir = readdir(d)))
    if (ssin(dir->d_name, ".htm") > 0) {
      l->refs[l->len] = 0;
      scpy(dir->d_name, l->files[l->len++], 64);
    }
  closedir(d);
  printf("Indexed %d terms\n", l->len);
  return 1;
}

void inspect(Lexicon* l) {
  int i;
  for (i = 0; i < l->len; ++i)
    if (!l->refs[i])
      error("Orphaned", l->files[i]);
}

int main(void) {
  Lexicon lex;
  DIR* d;
  lex.len = 0;
  if (!(d = opendir("inc")))
    return error("Open", "Missing inc/ folder. ");
  if (!index(&lex, d))
    return error("Indexing", "Failed");
  if (!generate(&lex))
    return error("Generating", "Failed");
  inspect(&lex);
  return 0;
}