#include <String.h>

#include <u.h>
#include <libc.h>
#include <bio.h>
#include <String.h>
#include <ctype.h>
#include <thread.h>
#include "wiki.h"

static Wpage*
mkwtxt(int type, char *text)
{
Wpage *w;

w = emalloc(sizeof(*w));
w->type = type;
w->text = text;
setmalloctag(w, getcallerpc(&type));
return w;
}

/*
* turn runs of whitespace into single spaces,
* eliminate whitespace at beginning and end.
*/
char*
strcondense(char *s, int cutbegin)
{
char *r, *w, *es;
int inspace;

es = s+strlen(s);
inspace = cutbegin;
for(r=w=s; *r; r++){
if(isspace(*r)){
if(!inspace){
inspace=1;
*w++ = ' ';
}
}else{
inspace=0;
*w++ = *r;
}
}
assert(w <= es);
if(inspace && w>s){
--w;
*w = '\0';
}
else
*w = '\0';
return s;
}

/*
* turn runs of Wplain into single Wplain.
*/
static Wpage*
wcondense(Wpage *wtxt)
{
Wpage *ow, *w;

for(w=wtxt; w; ){
if(w->type == Wplain)
strcondense(w->text, 1);

if(w->type != Wplain || w->next==nil
|| w->next->type != Wplain){
w=w->next;
continue;
}

w->text = erealloc(w->text, strlen(w->text)+1+strlen(w->next->text)+1);
strcat(w->text, " ");
strcat(w->text, w->next->text);

ow = w->next;
w->next = ow->next;
ow->next = nil;
freepage(ow);
}
return wtxt;
}

/*
* Parse a link, without the brackets.
*/
static Wpage*
mklink(char *s)
{
char *q;
Wpage *w;

for(q=s; *q && *q != '|'; q++)
;

if(*q == '\0'){
w = mkwtxt(Wlink, estrdup(strcondense(s, 1)));
w->url = nil;
}else{
*q = '\0';
w = mkwtxt(Wlink, estrdup(strcondense(s, 1)));
w->url = estrdup(strcondense(q+1, 1));
}
setmalloctag(w, getcallerpc(&s));
return w;
}

/*
* Parse Wplains, inserting Wlink nodes where appropriate.
*/
static Wpage*
wlink(Wpage *wtxt)
{
char *p, *q, *r, *s;
Wpage *w, *nw;

for(w=wtxt; w; w=nw){
nw = w->next;
if(w->type != Wplain)
continue;
while(w->text[0]){
p = w->text;
for(q=p; *q && *q != '['; q++)
;
if(*q == '\0')
break;
for(r=q; *r && *r != ']'; r++)
;
if(*r == '\0')
break;
*q = '\0';
*r = '\0';
s = w->text;
w->text = estrdup(w->text);
w->next = mklink(q+1);
w = w->next;
w->next = mkwtxt(Wplain, estrdup(r+1));
free(s);
w = w->next;
w->next = nw;
}
assert(w->next == nw);
}
return wtxt;
}

static int
ismanchar(int c)
{
return ('a' <= c && c <= 'z')
|| ('A' <= c && c <= 'Z')
|| ('0' <= c && c <= '9')
|| c=='_' || c=='-' || c=='.' || c=='/'
|| (c < 0); /* UTF */
}

static Wpage*
findmanref(char *p, char **beginp, char **endp)
{
char *q, *r;
Wpage *w;

q=p;
for(;;){
for(; q[0] && (q[0] != '(' || !isdigit(q[1]) || q[2] != ')'); q++)
;
if(*q == '\0')
break;
for(r=q; r>p && ismanchar(r[-1]); r--)
;
if(r==q){
q += 3;
continue;
}
*q = '\0';
w = mkwtxt(Wman, estrdup(r));
*beginp = r;
*q = '(';
w->section = q[1]-'0';
*endp = q+3;
setmalloctag(w, getcallerpc(&p));
return w;
}
return nil;
}

/*
* Parse Wplains, looking for man page references.
* This should be done by using a plumb(6)-style
* control file rather than hard-coding things here.
*/
static Wpage*
wman(Wpage *wtxt)
{
char *q, *r;
Wpage *w, *mw, *nw;

for(w=wtxt; w; w=nw){
nw = w->next;
if(w->type != Wplain)
continue;
while(w->text[0]){
if((mw = findmanref(w->text, &q, &r)) == nil)
break;
*q = '\0';
w->next = mw;
w = w->next;
w->next = mkwtxt(Wplain, estrdup(r));
w = w->next;
w->next = nw;
}
assert(w->next == nw);
}
return wtxt;
}

static int isheading(char *p) {
Rune r;
int hasupper=0;
while(*p) {
p+=chartorune(&r,p);
if(isupperrune(r))
hasupper=1;
else if(islowerrune(r))
return 0;
}
return hasupper;
}

Wpage*
Brdpage(char *(*rdline)(void*,int), void *b)
{
char *p, *c;
int waspara;
Wpage *w, **pw;

w = nil;
pw = &w;
waspara = 1;
while((p = rdline(b, '\n')) != nil){
if(p[0] != '!')
p = strcondense(p, 1);
if(p[0] == '\0'){
if(waspara==0){
waspara=1;
*pw = mkwtxt(Wpara, nil);
pw = &(*pw)->next;
}
continue;
}
waspara = 0;
switch(p[0]){
case '*':
*pw = mkwtxt(Wbullet, nil);
pw = &(*pw)->next;
*pw = mkwtxt(Wplain, estrdup(p+1));
pw = &(*pw)->next;
break;
case '!':
*pw = mkwtxt(Wpre, estrdup(p[1]==' '?p+2:p+1));
pw = &(*pw)->next;
break;
case '-':
for(c = p; *c != '\0'; c++) {
if(*c != '-') {
c = p;
break;
}
}

if( (c-p) > 4) {
*pw = mkwtxt(Whr, nil);
pw = &(*pw)->next;
break;
}
/* else fall thru */
default:
if(isheading(p)){
*pw = mkwtxt(Wheading, estrdup(p));
pw = &(*pw)->next;
continue;
}
*pw = mkwtxt(Wplain, estrdup(p));
pw = &(*pw)->next;
break;
}
}
if(w == nil)
werrstr("empty page");

*pw = nil;
w = wcondense(w);
w = wlink(w);
w = wman(w);
setmalloctag(w, getcallerpc(&rdline));

return w;
}

void
printpage(Wpage *w)
{
for(; w; w=w->next){
switch(w->type){
case Wpara:
print("para\n");
break;
case Wheading:
print("heading '%s'\n", w->text);
break;
case Wbullet:
print("bullet\n");
break;
case Wlink:
print("link '%s' '%s'\n", w->text, w->url);
break;
case Wman:
print("man %d %s\n", w->section, w->text);
break;
case Wplain:
print("plain '%s'\n", w->text);
break;
case Whr:
print("hr\n");
break;
case Wpre:
print("pre '%s'\n", w->text);
break;
}
}
}