#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <stdint.h>
#include "jfile.h"

#define DEFAULT_FILENAME    "data.jrf"
#define DEFAULT_FOLDER      "data/"

#pragma pack(push,1)
struct DATA_Header {
	char magic[4];
	uint32_t num_files;
	uint32_t index_offset;
};

struct DATA_Info {
	uint32_t	offset;
	uint32_t	length;
	char	name[13];
};

struct DATA_Index {
	DATA_Info*	file_info;
};

struct DATA_File {
	DATA_Header	header;
	DATA_Index	index;
};

#pragma pack(pop)

char *resource_filename = NULL;
char *resource_folder = NULL;
DATA_File *data_file = NULL;
int file_source = SOURCE_FILE;
char scratch[255];

void file_setresourcefilename(const char *str) {
    if (resource_filename != NULL) free(resource_filename);
    resource_filename = (char*)malloc(strlen(str)+1);
    strcpy(resource_filename, str);
}

void file_setresourcefolder(const char *str) {
    if (resource_folder != NULL) free(resource_folder);
    resource_folder = (char*)malloc(strlen(str)+1);
    strcpy(resource_folder, str);
}

void file_setsource(const int src) {
    file_source = src%2; // mod 2 so it always is a valid value, 0 (file) or 1 (folder)
	if (src==SOURCE_FOLDER && resource_folder==NULL) file_setresourcefolder(DEFAULT_FOLDER);
}

bool file_getdictionary() {
    if (resource_filename == NULL) file_setresourcefilename(DEFAULT_FILENAME);
    FILE* f = fopen(resource_filename, "rb");
	if (f) {
	    data_file = (DATA_File*)malloc(sizeof(DATA_File));
        fread((char*)&data_file->header, sizeof(DATA_Header), 1, f);
        fseek(f, data_file->header.index_offset, SEEK_SET);
    	data_file->index.file_info = (DATA_Info*)malloc(data_file->header.num_files * sizeof(DATA_Info));
        fread((char*)data_file->index.file_info, data_file->header.num_files * sizeof(DATA_Info), 1, f);
    	fclose(f);
        return true;
    } else {
        return false;
    }
}

char *file_getfilenamewithfolder(const char* filename) {
	strcpy(scratch, resource_folder);
	strcat(scratch, filename);
	return scratch;
}

FILE *file_getfilepointer(const char *resourcename, int& filesize, const bool binary) {

    if (file_source==SOURCE_FILE and not data_file) {
        if (not file_getdictionary()) file_setsource(SOURCE_FOLDER);
    }

    FILE *f;

    if (file_source==SOURCE_FILE) {
	    bool found = false;
	    uint32_t count = 0;
	    while( !found && count < data_file->header.num_files ) {
		    found = ( strcmp( resourcename, data_file->index.file_info[count].name ) == 0 );
		    if( !found ) count++;
	    }

	    if( !found ) {
		    perror("El recurs no s'ha trobat en l'arxiu de recursos");
		    exit(1);
	    }

	    filesize = data_file->index.file_info[count].length;

        f = fopen(resource_filename, binary?"rb":"r");
	    if (not f) {
		    perror("No s'ha pogut obrir l'arxiu de recursos");
		    exit(1);
	    }
        fseek(f, data_file->index.file_info[count].offset, SEEK_SET);
	} else {
		f = fopen(file_getfilenamewithfolder(resourcename), binary?"rb":"r");
		fseek(f, 0, SEEK_END);
		filesize = ftell(f);
        fseek(f, 0, SEEK_SET);
	}
	return f;
}

char *file_getfilebuffer(const char *resourcename, int& filesize) {
	FILE *f = file_getfilepointer(resourcename, filesize, true);
	char* buffer = (char*)malloc(filesize);
	fread(buffer, filesize, 1, f);
	fclose(f);
	return buffer;
}