//
//  VGMInterface.m
//  VGMStream
//
//  Created by Christopher Snowhill on 9/1/17.
//  Copyright 2017 __LoSnoCo__. All rights reserved.
//

#import "VGMInterface.h"

#import "Plugin.h"

#import "Logging.h"

static void log_callback(int level, const char* str) {
	ALog(@"%@", str);
}

void register_log_callback() {
	vgmstream_set_log_callback(VGM_LOG_LEVEL_ALL, &log_callback);
}

static STREAMFILE* open_cog_streamfile_buffer(const char* const filename, size_t buf_size);
static STREAMFILE* open_cog_streamfile_buffer_by_file(id infile, const char* const filename, size_t buf_size);

static size_t cogsf_read(COGSTREAMFILE* sf, uint8_t* dst, offv_t offset, size_t length) {
	size_t read_total = 0;

	if(!sf || !sf->infile || !dst || length <= 0 || offset < 0)
		return 0;

	//;VGM_LOG("cogsf: read %lx + %x (buf %lx + %x)\n", offset, length, sf->buf_offset, sf->valid_size);

	/* is the part of the requested length in the buffer? */
	if(offset >= sf->buf_offset && offset < sf->buf_offset + sf->valid_size) {
		size_t buf_limit;
		int buf_into = (int)(offset - sf->buf_offset);

		buf_limit = sf->valid_size - buf_into;
		if(buf_limit > length)
			buf_limit = length;

		//;VGM_LOG("cogsf: copy buf %lx + %x (+ %x) (buf %lx + %x)\n", offset, length_to_read, (length - length_to_read), sf->buf_offset, sf->valid_size);

		memcpy(dst, sf->buf + buf_into, buf_limit);
		read_total += buf_limit;
		length -= buf_limit;
		offset += buf_limit;
		dst += buf_limit;
	}

#ifdef VGM_DEBUG_OUTPUT
	if(offset < sf->buf_offset && length > 0) {
		// VGM_LOG("cogsf: rebuffer, requested %x vs %x (sf %x)\n", (uint32_t)offset, (uint32_t)sf->buf_offset, (uint32_t)sf);
		// sf->rebuffer++;
		// if (rebuffer > N) ...
	}
#endif
	NSObject* _file = (__bridge NSObject*)(sf->infile);
	id<CogSource> __unsafe_unretained file = (id)_file;

	/* read the rest of the requested length */
	while(length > 0) {
		size_t length_to_read;

		/* ignore requests at EOF */
		if(offset >= sf->file_size) {
			// offset = sf->file_size; /* seems fseek doesn't clamp offset */
			VGM_ASSERT_ONCE(offset > sf->file_size, "COGSF: reading over file_size 0x%x @ 0x%x + 0x%x\n", sf->file_size, (uint32_t)offset, length);
			break;
		}

		/* position to new offset */
		if(![file seek:offset whence:SEEK_SET]) {
			break; /* this shouldn't happen in our code */
		}

		/* fill the buffer (offset now is beyond buf_offset) */
		sf->buf_offset = offset;
		sf->valid_size = [file read:sf->buf amount:sf->buf_size];
		//;VGM_LOG("cogsf: read buf %lx + %x\n", sf->buf_offset, sf->valid_size);

		/* decide how much must be read this time */
		if(length > sf->buf_size)
			length_to_read = sf->buf_size;
		else
			length_to_read = length;

		/* give up on partial reads (EOF) */
		if(sf->valid_size < length_to_read) {
			memcpy(dst, sf->buf, sf->valid_size);
			offset += sf->valid_size;
			read_total += sf->valid_size;
			break;
		}

		/* use the new buffer */
		memcpy(dst, sf->buf, length_to_read);
		offset += length_to_read;
		read_total += length_to_read;
		length -= length_to_read;
		dst += length_to_read;
	}

	sf->offset = offset; /* last fread offset */
	return read_total;
}
static size_t cogsf_get_size(COGSTREAMFILE* sf) {
	return sf->file_size;
}
static offv_t cogsf_get_offset(COGSTREAMFILE* sf) {
	return sf->offset;
}
static void cogsf_get_name(COGSTREAMFILE* sf, char* name, size_t name_size) {
	int copy_size = sf->name_len + 1;
	if(copy_size > name_size)
		copy_size = name_size;

	memcpy(name, sf->name, copy_size);
	name[copy_size - 1] = '\0';
}

static STREAMFILE* cogsf_open(COGSTREAMFILE* sf, const char* const filename, size_t buf_size) {
	if(!filename)
		return NULL;

	if(sf->archname) {
		char finalname[PATH_LIMIT];
		const char* dirsep = NULL;
		const char* dirsep2 = NULL;

		// newly open files should be "(current-path)\newfile" or "(current-path)\folder\newfile", so we need to make
		// (archive-path = current-path)\(rest = newfile plus new folders)
		int filename_len = strlen(filename);

		if(filename_len > sf->archpath_end) {
			dirsep = &filename[sf->archpath_end];
		} else {
			dirsep = strrchr(filename, '\\'); // vgmstream shouldn't remove paths though
			dirsep2 = strrchr(filename, '/');
			if(dirsep2 > dirsep)
				dirsep = dirsep2;
			if(!dirsep)
				dirsep = filename;
			else
				dirsep += 1;
		}

		// TODO improve strops
		memcpy(finalname, sf->archname, sf->archfile_end); // copy current path+archive
		finalname[sf->archfile_end] = '\0';
		concatn(sizeof(finalname), finalname, dirsep); // paste possible extra dirs and filename

		// subfolders inside archives use "/" (path\archive.ext|subfolder/file.ext)
		for(int i = sf->archfile_end; i < sizeof(finalname); i++) {
			if(finalname[i] == '\0')
				break;
			if(finalname[i] == '\\')
				finalname[i] = '/';
		}

		// console::formatter() << "finalname: " << finalname;
		return open_cog_streamfile_buffer(finalname, buf_size);
	}

	// The file is already open, add a reference to existing file
	if(sf->infile && !strcmp(sf->name, filename)) {
		// Already retained by sf, will be retained again if used
		NSObject* _file = (__bridge NSObject*)(sf->infile);
		id<CogSource> __unsafe_unretained file = (id)_file;

		STREAMFILE* new_sf = open_cog_streamfile_buffer_by_file(file, filename, buf_size);

		if(new_sf) {
			return new_sf;
		}
		// Failure, try default open method
	}

	// a normal open, open a new file
	return open_cog_streamfile_buffer(filename, buf_size);
}

static void cogsf_close(COGSTREAMFILE* sf) {
	if(sf->infile)
		CFBridgingRelease(sf->infile);
	free(sf->name);
	free(sf->archname);
	free(sf->buf);
	free(sf);
}

static STREAMFILE* open_cog_streamfile_buffer_by_file(id<CogSource> infile, const char* const filename, size_t buf_size) {
	uint8_t* buf = NULL;
	COGSTREAMFILE* this_sf = NULL;

	buf = calloc(buf_size, sizeof(uint8_t));
	if(!buf) goto fail;

	this_sf = calloc(1, sizeof(COGSTREAMFILE));
	if(!this_sf) goto fail;

	this_sf->vt.read = (void*)cogsf_read;
	this_sf->vt.get_size = (void*)cogsf_get_size;
	this_sf->vt.get_offset = (void*)cogsf_get_offset;
	this_sf->vt.get_name = (void*)cogsf_get_name;
	this_sf->vt.open = (void*)cogsf_open;
	this_sf->vt.close = (void*)cogsf_close;

	if(infile) {
		this_sf->infile = (void*)CFBridgingRetain(infile);
	}

	this_sf->buf_size = buf_size;
	this_sf->buf = buf;

	this_sf->name = strdup(filename);
	if(!this_sf->name) goto fail;
	this_sf->name_len = strlen(this_sf->name);

	// Cog supports archives in unpack:// paths, similar to foobar2000
	if(strncmp(filename, "unpack", 6) == 0) {
		const char* archfile_ptr = strrchr(this_sf->name, '|');
		char temp_save;
		char* temp_null = 0;
		if(archfile_ptr) {
			this_sf->archfile_end = (intptr_t)archfile_ptr + 1 - (intptr_t)this_sf->name;

			// So we search for the last slash in the source path
			temp_null = archfile_ptr;
			temp_save = *temp_null;
			*temp_null = '\0';
		}

		const char* archpath_ptr = strrchr(this_sf->name, '/');
		if(archpath_ptr)
			this_sf->archpath_end = (intptr_t)archpath_ptr + 1 - (intptr_t)this_sf->name;

		if(temp_null)
			*temp_null = temp_save;

		if(this_sf->archpath_end <= 0 || this_sf->archfile_end <= 0 || this_sf->archpath_end > this_sf->name_len || this_sf->archfile_end >= PATH_LIMIT) {
			// ???
			this_sf->archpath_end = 0;
			this_sf->archfile_end = 0;
		} else {
			this_sf->archname = strdup(filename);
			if(!this_sf->archname) goto fail;
			this_sf->archname_len = this_sf->name_len;

			// change from "(path)/(archive)|(filename)" to "(path)/(filename)"
			this_sf->name[this_sf->archpath_end] = '\0';
			concatn(this_sf->name_len, this_sf->name, &this_sf->archname[this_sf->archfile_end]);
		}
	}

	/* cache file_size */
	if(infile) {
		[infile seek:0 whence:SEEK_END];
		this_sf->file_size = [infile tell];
		[infile seek:0 whence:SEEK_SET];
	} else {
		this_sf->file_size = 0; /* allow virtual, non-existing files */
	}

	/* Typically fseek(o)/ftell(o) may only handle up to ~2.14GB, signed 32b = 0x7FFFFFFF
	 * (happens in banks like FSB, though rarely). Should work if configured properly, log otherwise. */
	if(this_sf->file_size == 0xFFFFFFFF) { /* -1 on error */
		vgm_logi("STREAMFILE: file size too big (report)\n");
		goto fail; /* can be ignored but may result in strange/unexpected behaviors */
	}

	return &this_sf->vt;

fail:
	if(this_sf) {
		if(this_sf->infile)
			CFBridgingRelease(this_sf->infile);
		free(this_sf->archname);
		free(this_sf->name);
	}
	free(buf);
	free(this_sf);
	return NULL;
}

static STREAMFILE* open_cog_streamfile_buffer_from_url(NSURL* url, const char* const filename, size_t bufsize) {
	id<CogSource> infile;
	STREAMFILE* sf = NULL;

	id audioSourceClass = NSClassFromString(@"AudioSource");
	infile = [audioSourceClass audioSourceForURL:url];

	if(![infile open:url]) {
		/* allow non-existing files in some cases */
		if(!vgmstream_is_virtual_filename(filename))
			return NULL;
	}

	if(![infile seekable])
		return NULL;

	return open_cog_streamfile_buffer_by_file(infile, filename, bufsize);
}

static STREAMFILE* open_cog_streamfile_buffer(const char* const filename, size_t bufsize) {
	NSString* urlString = [NSString stringWithUTF8String:filename];
	NSURL* url = [NSURL URLWithDataRepresentation:[urlString dataUsingEncoding:NSUTF8StringEncoding] relativeToURL:nil];

	if([url fragment]) {
		// .TXTP fragments need an override here
		NSString* frag = [url fragment];
		NSUInteger len = [frag length];
		if(len > 5 && [[frag substringFromIndex:len - 5] isEqualToString:@".txtp"]) {
			urlString = [urlString stringByReplacingOccurrencesOfString:@"#" withString:@"%23"];
			url = [NSURL URLWithDataRepresentation:[urlString dataUsingEncoding:NSUTF8StringEncoding] relativeToURL:nil];
		}
	}

	return open_cog_streamfile_buffer_from_url(url, filename, bufsize);
}

STREAMFILE* open_cog_streamfile_from_url(NSURL* url) {
	return open_cog_streamfile_buffer_from_url(url, [[[url absoluteString] stringByRemovingPercentEncoding] UTF8String], STREAMFILE_DEFAULT_BUFFER_SIZE);
}

STREAMFILE* open_cog_streamfile(const char* filename) {
	return open_cog_streamfile_buffer(filename, STREAMFILE_DEFAULT_BUFFER_SIZE);
}

// STREAMFILE* open_cog_streamfile_by_file(id<CogSource> file, const char* filename) {
//     return open_cog_streamfile_buffer_by_file(file, filename, STREAMFILE_DEFAULT_BUFFER_SIZE);
// }

VGMSTREAM* init_vgmstream_from_cogfile(const char* path, int subsong) {
	STREAMFILE* sf;
	VGMSTREAM* vgm = NULL;

	sf = open_cog_streamfile(path);

	if(sf) {
		sf->stream_index = subsong;
		vgm = init_vgmstream_from_STREAMFILE(sf);
		cogsf_close((COGSTREAMFILE*)sf);
	}

	return vgm;
}