#include <assert.h>

#include <debug.h>

#include <string/new.h>
#include <string/free.h>

#include <stringtree/new.h>
#include <stringtree/append.h>
#include <stringtree/prepend.h>
#include <stringtree/free.h>

#include "struct.h"
#include "prettyprint.h"

static struct stringtree* prettyprint_mpn(
    mpz_srcptr printme,
    const wchar_t* digits)
{
    ENTER;
    
    struct stringtree* tree = new_stringtree();
    
    mpz_t countdown, digit, ten;
    
    mpz_init(digit);
    
    mpz_init_set_ui(ten, 10);
    
    mpz_init_set(countdown, printme);
    
    assert(mpz_sgn(countdown) >= 0);
    
    if (mpz_sgn(countdown) == 0)
    {
        stringtree_append_cstr(tree, L"0");
    }
    else while (mpz_sgn(countdown))
    {
        mpz_fdiv_qr(countdown, digit, countdown, ten);
        
        wchar_t wc = digits[mpz_get_ui(digit)];
        
        dpvwc(wc);
        
        struct string* d = new_string(&wc, 1);
        
        stringtree_prepend_string(tree, d);
        
        free_string(d);
    }
    
    mpz_clear(countdown);
    
    mpz_clear(digit);
    
    mpz_clear(ten);
    
    EXIT;
    return tree;
}

struct stringtree* number_prettyprint(
    struct number* this)
{
    ENTER;
    
    struct stringtree* tree = new_stringtree();
    
    mpq_t clone;
    
    mpq_init(clone);
    
    mpq_set(clone, this->number);
    
    if (mpq_sgn(clone) < 0)
    {
        stringtree_append_cstr(tree, L"-");
        
        mpq_abs(clone, clone);
    }
    
    mpz_t whole;
    
    mpz_init(whole);
    
    mpz_fdiv_q(whole, mpq_numref(clone), mpq_denref(clone));
    
    struct stringtree* whole_tree = prettyprint_mpn(whole, L"0123456789");
    
    stringtree_append_stringtree(tree, whole_tree);
    
    // subtract whole out of clone:
    {
        mpq_t tmp;
        
        mpq_init(tmp);
        
        mpq_set_z(tmp, whole);
        
        mpq_sub(clone, clone, tmp);
        
        mpq_clear(tmp);
    }
    
    // print decimal:
    if (mpq_sgn(clone))
    {
        struct stringtree* num_tree = prettyprint_mpn(
            mpq_numref(clone), L"⁰¹²³⁴⁵⁶⁷⁸⁹");
        
        struct stringtree* den_tree = prettyprint_mpn(
            mpq_denref(clone), L"₀₁₂₃₄₅₆₇₈₉");
        
        // stringtree_append_cstr(tree, L" ");
        
        stringtree_append_stringtree(tree, num_tree);
        
        stringtree_append_cstr(tree, L"/");
        
        stringtree_append_stringtree(tree, den_tree);
        
        free_stringtree(num_tree);
        
        free_stringtree(den_tree);
    }
    
    free_stringtree(whole_tree);
    
    mpz_clear(whole);
    
    mpq_clear(clone);
    
    EXIT;
    return tree;
}