#include "im.h"
#include "errloc.h"
#include "fn.h"
#include "prv.h"
#include "parse.h"
#include <errno.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

void im_free(struct im *im)
{
    ast_free(&im->ast);
    lex_free(&im->l);
}

static int doim(const struct lex *l, const struct tk *tk, struct prv *p)
{
    int ret = -1;
    FILE *f = NULL;
    struct im *im;
    struct fn *fn = fn_cur(p);
    struct ast *ast;
    size_t n = fn->nimps + 1;
    const char *path = tk->s;

    if (!strcmp(l->loc.f, path))
    {
        errloc(tk, "detected recursive import \"%s\"", path);
        goto end;
    }
    /* TODO: honor -I flags */
    if (!(f = fopen(path, "rb")))
    {
        errloc(tk, "could not find import: \"%s\"", path);
        goto end;
    }
    else if (!(im = realloc(fn->imps, n * sizeof *im)))
    {
        perror("realloc(3)");
        goto end;
    }

    fn->imps = im;
    im = &fn->imps[fn->nimps++];
    *im = (struct im){.l.loc.f = path};
    ast = &im->ast;

    if (!(ast->fns = malloc(sizeof *ast->fns)))
    {
        perror("malloc(3)");
        goto end;
    }

    *ast->fns = (struct fn){.tk = tk};
    /* hack: treat imports as a function */
    ast->nfns = 1;

    if (lex(&im->l, f) || parse_im(&im->l, ast))
        goto end;

    ret = 0;

end:

    if (f && fclose(f))
    {
        fprintf(stderr, "fclose(3) %s: %s\n", path, strerror(errno));
        ret = -1;
    }

    return ret;
}

int im(const struct lex *l, struct prv *p)
{
    const struct tk *tk = p->stk + 1;
    struct pos *pos = &p->pos[p->i];

    while (!lex_eof(l, tk) && !kw(tk->s))
        if (doim(l, tk++, p))
            return -1;

    pos->seq = pos->stseq;
    pos->step = pos->seq->steps;
    p->stk = p->tk;
    return 1;
}