#include "cc.h"
#include <libn/macro/map.h>

// -----------------------------------------------------------------------
// string interning

/* jenkins' one at a time hash */
static 
int32
hash_string(byte* s)
{
    int32 h;

    h = 0; 
    if (s != nil) {
        for (; *s; ++s) {
            h += *s;
            h  = (h << 10);
            h  = (h >> 6);
        }
    }

    h += (h << 3);
    h ^= (h >> 11);
    h += (h >> 11);

    return h;
}

static
int
streq(byte *s, byte *t)
{
    if (s == nil) {
        if (t == nil) 
            return 1;
        else
            return 0;
    }

    return (t == nil) ? 0 : strcmp(s, t) == 0;
}

#define HASH(s)      hash_string(s)
#define EQUAL(s, t) (streq(s, t))
static
int
getstr(string key, int *ok)
{
    int idx;
    MAP_GET(idx, (&C.strs), key, HASH, EQUAL);

    *ok = idx < C.strs.n_buckets;
    return idx; 
}

static
int
morestrtab(StrTab *tab, int n)
{
    MAP_GROW(tab, string, int32, n, HASH, ·calloc, ·free, nil);
}

static
int
putstr(byte *s, error *err)
{
    int sz;
    sz = C.strs.size; 
    MAP_PUT((&C.strs), s, sz, HASH, EQUAL, morestrtab, err);
}
#undef HASH
#undef EQUAL

int32
intern(byte **s)
{
    int i, ok;

    i = getstr(*s, &ok);
    if (ok) {
        *s = C.strs.keys[i];
        goto END;
    }

    *s = str·make(*s);
    i  = putstr(*s, &ok);
    C.strs.vals[i] = C.strs.size - 1;

END:
    return C.strs.vals[i];
}

// -----------------------------------------------------------------------
// io buffer management

#define asrdr(x) (io·Reader){(int (*)(void *, int, int, void *))x}
// path should be absolute 
Io*
openio(byte *path)
{
    string *it, *end;
    Stream *f;

    intern(&path);

    // See if we have already opened file;
    // If so, and it hasn't been flagged return it
    for (it = C.omit.path, end = it + C.omit.len; it < end; ++it) {
        if ((uintptr)(*it) == (uintptr)(path))
            return nil;
    }

    printf("OPENING PATH %s\n", path);

    if ((C.io - C.iostk) >= arrlen(C.iostk)-1) 
        panicf("out of I/O space!");

    C.io->f = io·open(path, "r");
    if (!C.io->f)
        panicf("file %s not found", path);

    C.io->kind = IOfile;
    C.io->path = path;
    bufio·initreader(&C.io->buf, asrdr(io·read), C.io->f);

    return C.io++;
} 

Io*
makeio()
{
    if ((C.io - C.iostk) >= arrlen(C.iostk)-1) 
        panicf("out of I/O space!");

    C.io->path = "<buffer>";
    C.io->buf = (io·Buffer) {
        .state    = bufio·rdr | bufio·end, 
        .runesize = 0,
        .h        = nil,
        .size     = bufio·size,
        .beg      = C.io->buf.buf + bufio·ungets,
        .pos      = C.io->buf.buf + bufio·ungets,
        .end      = C.io->buf.buf + bufio·ungets,
    };
    C.io->b = C.io->buf.beg;

    return C.io++;
} 
#undef asrdr

void
freeio(Io *io)
{
    if (io->kind & IOfile) {
        io·close(io->f);
    }
    io->kind  = 0;
    io->link  = nil;
    io->path  = nil;
    io->store = (Pos){ 0 };
}

void
pushomit(string omit)
{
    if (C.omit.len == C.omit.cap) {
        C.omit.cap += 20;
        C.omit.path = realloc(C.omit.path, C.omit.cap*sizeof(*C.omit.path));
    }
    C.omit.path[C.omit.len++] = omit;
}

// -----------------------------------------------------------------------
// universal compiler builtins

#define KEYWORD(a, b) b,
byte *keywords[NUM_KEYWORDS] = { KEYWORDS };
#undef KEYWORD

#define DIRECTIVE(a, b, c) b,
byte *directives[NUM_DIRECTIVES] = { DIRECTIVES };
#undef DIRECTIVE

struct Compiler C = { 0 }; 

// -----------------------------------------------------------------------
// cli flag handlers

void
pushinclude(byte *dirs)
{
    string d, s, *it, *end;

    while (*dirs != '\0') {
        d = strchr(dirs, ' ');
        if (d != nil)
            *d = '\0';

        s = dirs;
        intern(&s);
        for (it = C.inc.dir, end = it + C.inc.len; it != end; ++it) {
            if ((uintptr)s == (uintptr)(*it))
                goto Nextdir;
        }

        if (C.inc.len == C.inc.cap) {
            C.inc.cap += 20;
            C.inc.dir = realloc(C.inc.dir, C.inc.cap*sizeof(*C.inc.dir));
        }
        C.inc.dir[C.inc.len++] = s;
Nextdir:
        if (d == nil)
            break;
        dirs = d + 1;
    }
}

// -----------------------------------------------------------------------
// main point of entry

void
init(void)
{
    int i;

    for (i = 0; i < arrlen(keywords); i++) {
        intern(&keywords[i]);
    }

    for (i = 0; i < arrlen(directives); i++) {
        intern(&directives[i]);
    }

    C.heap    = mem·makearena(mem·sys, nil);

    C.inc.len = 0;
    C.inc.cap = 100;
    C.inc.dir = calloc(C.inc.cap, sizeof(*C.inc.dir));
    C.inc.dir[C.inc.len++] = ".";

    C.omit.len  = 0;
    C.omit.cap  = 100;
    C.omit.path = calloc(C.omit.cap, sizeof(*C.inc.dir));

    C.outfile  = nil;
    C.io       = C.iostk;
    C.io->link = nil;
    memset(C.iostk, 0, sizeof(C.iostk));

    C.lxr     = (Lexer){ 0 };
}

error
compile(byte *path)
{
    Io    *io;
    Token tok;
    byte *p, out[400];

    intern(&path);
    strcpy(out, path);

    p = utf8·findrrune(out, '/');
    if (p) 
        *p++ = '\0';
    else
        p = out; 

    if (!C.outfile) {
        C.outfile = p;
        if (C.outfile) {
            if ((p = utf8·findrrune(C.outfile, '.'))) {
                p[0] = '.';
                p[1] = 'o';
                p[2] = '\0';
            }
        } else {
            C.outfile = "/dev/null";
        }
    }

    C.lxr.io  = openio(path);
    C.lxr.pos = (Pos){
        .path = path,
        .line = 1,
        .col  = 1,
    };

    while (tok = lex(&C.lxr), tok.kind > Aeof) {
        // puttok(tok);
    }

    return tok.kind != Anil;
}

error
main(int argc, byte *argv[])
{
    byte *a, *src;
    int   err;

    init();

    ARGBEGIN {
    case 'o':
        C.outfile = ARGF();
        break;

    case 'D':
        a = ARGF();
        if (a) {
            intern(&a);
            dodefine(&C.lxr, a);
        }
        break;

    case 'I':
        a = ARGF();
        if (a)
            pushinclude(a);
        break;
    } ARGEND

    if (argc < 1 && C.outfile == nil) {
        printf("usage: cc [-options] files\n");
        exit(1);
    }

    // NOTE: This is just for my comfort during debugging.
    pushinclude("/home/nolln/root/include");
    pushinclude("/home/nolln/root/include/vendor/libc");
    
    src = (argc == 0) ? "<stdin>" : argv[0];
    intern(&src);

    if ((err = compile(src)), err) {
        exit(2);
    }

    exit(0);
}