#include <stdio.h>
#include "parser.h"
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <stdbool.h>
#include <string.h>

static char preprocessed_fname[] = "/tmp/cxlppXXXXXX";
static char c_fname[] = "/tmp/cxlcXXXXXX.c";
static bool preprocessed_fname_created = false;
static bool c_fname_created = false;

bool preprocess(const char * input_fname)
{
    int fd = mkstemp(preprocessed_fname);
    if (fd < 0)
    {
        perror("mkstemp");
        return false;
    }
    preprocessed_fname_created = true;
    pid_t pid = fork();
    if (pid < 0)
    {
        perror("fork");
        return false;
    }
    else if (pid == 0)
    {
        dup2(fd, STDOUT_FILENO);
        close(fd);
        execlp("gcc", "gcc", "-x", "c", "-E", input_fname, NULL);
    }
    else
    {
        close(fd);
        waitpid(pid, NULL, 0);
    }
    return true;
}

void write_node(FILE * file, Node * node)
{
    switch (node->type)
    {
    case NODE_TYPE_LIST:
        {
            bool space = false;
            for (auto subnode : *node->list)
            {
                if (space)
                {
                    fprintf(file, " ");
                }
                write_node(file, subnode);
                space = true;
            }
        }
        break;
    case NODE_TYPE_TOKEN:
        fprintf(file, "%s", node->token.text->c_str());
        if (*node->token.text == ";")
        {
            fprintf(file, "\n");
        }
        break;
    }
}

bool emit_c(Node * node)
{
    int fd = mkstemps(c_fname, 2);
    if (fd < 0)
    {
        perror("mkstemp");
        return false;
    }
    FILE * file = fdopen(fd, "w");
    c_fname_created = true;
    write_node(file, node);
    fclose(file);
    return true;
}

bool compile()
{
    pid_t pid = fork();
    if (pid < 0)
    {
        perror("fork");
        return false;
    }
    else if (pid == 0)
    {
        execlp("gcc", "gcc", "-c", c_fname, "-o", "out.o", NULL);
    }
    else
    {
        waitpid(pid, NULL, 0);
    }
    return true;
}

int main(int argc, char * argv[])
{
    bool preprocess_successful = preprocess(argv[1]);
    if (preprocess_successful)
    {
        Node * node = parse(preprocessed_fname);
        if (node != nullptr)
        {
            if (emit_c(node))
            {
                compile();
            }
        }
    }
    /* Clean up temporary files. */
    if (preprocessed_fname_created)
    {
        unlink(preprocessed_fname);
    }
    if (c_fname_created)
    {
        unlink(c_fname);
    }

    return 0;
}