#include "io_file_op.hpp"
#include <string.h>

FILE *w_open_file(const char *filepath)
{
    if (filepath == nullptr)
    {
        return nullptr;
    }
    FILE *file = fopen(filepath, "rwb");
    return file;
}

file_content w_read_file(FILE *file)
{
    file_content __result = init_file_content();

    if (file == nullptr)
    {
        fprintf(stderr, "Error: Invalid file in w_read_file\n");
        return __result;
    }

    fseek(file, 0, SEEK_END);
    long file_size = ftell(file);
    if (file_size < 0)
    {
        fprintf(stderr, "Error: Could not determine file size.\n");
        return init_file_content();
    }
    rewind(file);

    size_t size = (size_t)file_size;
    char *buffer = (char *)malloc(sizeof(char) * (size + 1));
    if (buffer == NULL)
    {
        fprintf(stderr, "Error: Cant Allocate buffer to read.\n");
        return init_file_content();
    }

    size_t result = fread(buffer, 1, size, file);
    if (result != size)
    {
        fprintf(stderr, "Error: Reading error in w_read_file.\n");
        free(buffer);
        return init_file_content();
    }
    buffer[size] = '\0';

    size_t line_start = 0;
    char **lines = NULL;

    for (size_t i = 0; i <= size; i++)
    {
        if (buffer[i] == '\n' || buffer[i] == '\0')
        {
            size_t line_length = i - line_start;
            char *line = (char *)malloc(line_length + 1);
            if (line == NULL)
            {
                for (int j = 0; j < __result.num_lines; j++)
                    free(lines[j]);
                free(lines);
                free(buffer);
                fprintf(stderr, "Error: Cant Allocate line buffer.\n");
                return init_file_content();
            }
            memcpy(line, &buffer[line_start], line_length);
            line[line_length] = '\0';
            char **new_lines = (char **)realloc(lines, ((size_t)(__result.num_lines + 1)) * sizeof(char *));
            if (new_lines == NULL)
            {
                for (int j = 0; j < __result.num_lines; j++)
                    free(lines[j]);
                free(line);
                free(lines);
                free(buffer);
                fprintf(stderr, "Error: Cant realloc lines array.\n");
                return init_file_content();
            }
            lines = new_lines;
            lines[__result.num_lines++] = line;
            line_start = i + 1;
        }
    }
    __result.lines = lines;
    return __result;
}

void w_close_file(FILE *file)
{
    if (file != NULL)
    {
        fclose(file);
    }
}

file_content init_file_content()
{
    file_content r;
    r.lines = NULL;
    r.num_lines = 0;
    return r;
}