#include "parse.h"
#include "report.h"
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef struct {
    char* input_file;
    char* output_file;
} Args;

static int parse_args(Args* args, int argc, char** argv);

static char* read_text_file(const char* filename);

int main(int argc, char** argv)
{
    Args args;
    if (parse_args(&args, argc, argv) != 0) {
        return EXIT_FAILURE;
    }

    char* text = read_text_file(args.input_file);
    if (!text) {
        return EXIT_FAILURE;
    }

    Parser* parser = parser_new(args.input_file, text);

    size_t lines_capacity = 1024;
    PLine** lines = malloc(sizeof(PLine*) * lines_capacity);
    size_t lines_size = 0;

    while (!parser_done(parser)) {
        if (parser_next_is_const(parser)) {
            PConst* stmt = parser_parse_const(parser);

        } else if (parser_next_is_include(parser)) {
            PInclude* stmt = parser_parse_include(parser);

        } else {
            PLabel* label;
            while ((label = parser_parse_label(parser)) != nullptr) { }
        }
    }

    return EXIT_SUCCESS;
}

int parse_args(Args* args, int argc, char** argv)
{
    *args = (Args) {
        .input_file = nullptr,
        .output_file = nullptr,
    };

    int i = 1;
    while (i < argc) {
        if (strcmp(argv[i], "-o") == 0) {
            i += 1;
            if (i >= argc) {
                fprintf(stderr, FMT_ERROR("expected filename after '-o'"));
                return 1;
            }
            args->output_file = argv[i];
            i += 1;
        } else if (argv[i][0] == '-') {
            fprintf(stderr, FMT_ERROR("unrecognized argument '%s'"), argv[i]);
            return 1;
        } else {
            if (args->input_file != nullptr) {
                fprintf(stderr, FMT_ERROR("multiple input files"));
                return 1;
            }
            args->input_file = argv[i];
            i += 1;
        }
    }

    if (!args->input_file) {
        fprintf(stderr, FMT_ERROR("no input file"));
        return 1;
    }

    return 0;
}

char* read_text_file(const char* filename)
{
    FILE* fp = fopen(filename, "r");
    if (!fp) {
        fprintf(stderr,
            FMT_ERROR("could not open file '%s' for reading: %s"),
            filename,
            strerror(errno));
        return NULL;
    }
    fseek(fp, 0L, SEEK_END);
    size_t file_size = (size_t)ftell(fp);
    rewind(fp);

    char* text = calloc(file_size + 1, sizeof(char));
    size_t bytes_read = fread(text, sizeof(char), file_size, fp);
    fclose(fp);
    if (bytes_read != file_size) {
        fprintf(stderr,
            FMT_ERROR("could not read input file '%s': %s"),
            filename,
            strerror(errno));
        return NULL;
    }
    return text;
}