#include <stdio.h>
#include <stdlib.h>
#include <emscripten/val.h>

#include "canvas_graph.hpp"

using namespace emscripten;

static std::vector<Expression> s_exprs;

int main() {
    return 0;
}

extern "C" void set_num_exprs(size_t num_exprs) {
    s_exprs.resize(num_exprs);
}

extern "C" void set_expr(size_t idx, const char *expr) {
    if (idx >= s_exprs.size())
        return;

    s_exprs[idx].SetExpression(expr);
}

extern "C" void print_errors() {
    const val document = val::global("document");
    val p = document.call<val>("getElementById", val("output"));

    std::string errors;

    for (const auto& expr : s_exprs) {
        const char* error_text = expr.GetErrorText();
        if (error_text) {
            errors += error_text;
            errors += "\n";
        }
    }

    p.set("innerText", errors.c_str());
}

extern "C" void draw_graph(double xmin, double xmax, double ymin, double ymax, double pointer_x, double pointer_y) {
    struct graph_range range = {xmin, xmax, ymin, ymax};
    canvas_generate_graph(s_exprs.data(), s_exprs.size(), &range, pointer_x, pointer_y);
}