module szip

#flag -I @VROOT/thirdparty/zip
#include "zip.c"
#include "zip.h"

struct C.zip_t {}

type Zip = C.zip_t

fn C.zip_open(byteptr, int, byte) &Zip
fn C.zip_close(&Zip)
fn C.zip_entry_open(&Zip, byteptr) int
fn C.zip_entry_close(&Zip) int
fn C.zip_entry_name(&Zip) byteptr
fn C.zip_entry_index(&Zip) int
fn C.zip_entry_isdir(&Zip) int
fn C.zip_entry_size(&Zip) u64
fn C.zip_entry_crc32(&Zip) u32
fn C.zip_entry_write(&Zip, voidptr, int) int
fn C.zip_entry_fwrite(&Zip, byteptr) int
fn C.zip_entry_read(&Zip, byteptr, int) int
fn C.zip_entry_fread(&Zip, byteptr) int
fn C.zip_total_entries(&Zip) int

// Ref - miniz.h
const (
	no_compression      = 0
	best_speed          = 1
	best_compression    = 9
	uber_compression    = 10
	default_level       = 6
	default_compression = -1
)

const (
	m_write  = `w`
	m_ronly  = `r`
	m_append = `a`
)

/*
open opens zip archive with compression level using the given mode.

@param zipname zip archive file name.
@param level compression level (0-9 are the standard zlib-style levels).
@param mode file access mode.
        - 'r': opens a file for reading/extracting (the file must exists).
        - 'w': creates an empty file for writing.
        - 'a': appends to an existing archive.

@return the zip archive handler or NULL on error
*/
pub fn open(name string, level int, mode byte) ?&Zip {
	mut nlevel := level
	if (nlevel & 0xF) > uber_compression {
		nlevel = default_level
	}
	if name.len == 0 {
		return error('szip: name of file empty')
	}
	if mode !in [m_write, m_ronly, m_append] {
		return error('szip: invalid provided open mode')
	}
	p_zip := &Zip(C.zip_open(name.str, nlevel, mode))
	if isnil(p_zip) {
		return error('szip: cannot open/create/append new zip archive')
	}
	return p_zip
}

/*
close closes the zip archive, releases resources - always finalize.

@param zip zip archive handler.
*/
pub fn (mut z Zip) close() {
	C.zip_close(z)
}

/*
open_entry opens an entry by name in the zip archive.

For zip archive opened in 'w' or 'a' mode the function will append
a new entry. In readonly mode the function tries to locate the entry
in global dictionary.

@param zip zip archive handler.
@param entryname an entry name in local dictionary.

@return the return code - 0 on success, negative number (< 0) on error.
*/
pub fn (mut zentry Zip) open_entry(name string) ? {
	res := C.zip_entry_open(zentry, name.str)
	if res == -1 {
		return error('szip: cannot open archive entry')
	}
}

/*
* close_entry closes a zip entry, flushes buffer and releases resources.
 *
 * @param zip zip archive handler.
 *
 * @return the return code - 0 on success, negative number (< 0) on error.
*/
pub fn (mut zentry Zip) close_entry() {
	C.zip_entry_close(zentry)
}

/*
name returns a local name of the current zip entry.

The main difference between user's entry name and local entry name
is optional relative path.
Following .ZIP File Format Specification - the path stored MUST not contain
a drive or device letter, or a leading slash.
All slashes MUST be forward slashes '/' as opposed to backwards slashes '\'
for compatibility with Amiga and UNIX file systems etc.

@param zip: zip archive handler.

@return the pointer to the current zip entry name, or NULL on error.
*/
pub fn (mut zentry Zip) name() string {
	name := C.zip_entry_name(zentry)
	if name == 0 {
		return ''
	}
	return tos_clone(name)
}

/*
index returns an index of the current zip entry.

@param zip zip archive handler.

@return the index on success, negative number (< 0) on error.
*/
pub fn (mut zentry Zip) index() ?int {
	index := int(C.zip_entry_index(zentry))
	if index == -1 {
		return error('szip: cannot get current index of zip entry')
	}
	return index // must be check for INVALID_VALUE
}

/*
isdir determines if the current zip entry is a directory entry.

@param zip zip archive handler.

@return the return code - 1 (true), 0 (false), negative number (< 0) on
         error.
*/
pub fn (mut zentry Zip) isdir() ?bool {
	isdir := C.zip_entry_isdir(zentry)
	if isdir < 0 {
		return error('szip: cannot check entry type')
	}
	return isdir == 1
}

/*
size returns an uncompressed size of the current zip entry.

@param zip zip archive handler.

@return the uncompressed size in bytes.
*/
pub fn (mut zentry Zip) size() u64 {
	return C.zip_entry_size(zentry)
}

/*
crc32 returns CRC-32 checksum of the current zip entry.

@param zip zip archive handler.

@return the CRC-32 checksum.
*/
pub fn (mut zentry Zip) crc32() u32 {
	return C.zip_entry_crc32(zentry)
}

/*
write_entry compresses an input buffer for the current zip entry.

@param zip zip archive handler.
@param buf input buffer.
@param bufsize input buffer size (in bytes).

@return the return code - 0 on success, negative number (< 0) on error.
*/
pub fn (mut zentry Zip) write_entry(data []byte) ? {
	if (data[0] & 0xff) == -1 {
		return error('szip: cannot write entry')
	}
	buf := data // alias of data
	res := C.zip_entry_write(zentry, buf.data, buf.len)
	if res != 0 {
		return error('szip: failed to write entry')
	}
}

/*
create_entry compresses a file for the current zip entry.

@param zip zip archive handler.
@param filename input file.

@return the return code - 0 on success, negative number (< 0) on error.
*/
pub fn (mut zentry Zip) create_entry(name string) ? {
	res := C.zip_entry_fwrite(zentry, name.str)
	if res != 0 {
		return error('szip: failed to create entry')
	}
}

/*
read_entry extracts the current zip entry into output buffer.

The function allocates sufficient memory for an output buffer.

@param zip zip archive handler.
@param buf output buffer.
@param bufsize output buffer size (in bytes).

@note remember to release the memory allocated for an output buffer.
for large entries, please take a look at zip_entry_extract function.

@return the return code - the number of bytes actually read on success.
         Otherwise a -1 on error.
*/
pub fn (mut zentry Zip) read_entry() ?voidptr {
	mut buf := voidptr(0)
	mut bsize := i64(0)
	res := C.zip_entry_read(zentry, &buf, &bsize)
	if res == -1 {
		return error('szip: cannot read properly data from entry')
	}
	return buf
}

/*
extract_entry extracts the current zip entry into output file.

@param zip zip archive handler.
@param filename output file.

@return the return code - 0 on success, negative number (< 0) on error.
*/
pub fn (mut zentry Zip) extract_entry(path string) ? {
	if C.access(charptr(path.str), 0) == -1 {
		return error('Cannot open file for extracting, file not exists')
	}
	res := C.zip_entry_fread(zentry, path.str)
	if res != 0 {
		return error('szip: failed to extract entry')
	}
}

/*
extract extracts the current zip entry using a callback function (on_extract).

@param zip zip archive handler.
@param on_extract callback function.
@param arg opaque pointer (optional argument, which you can pass to the
        on_extract callback)

@return the return code - 0 on success, negative number (< 0) on error.
*/
/*
fn (mut zentry Zip) extract(path string) bool {
    if C.access(path.str, 0) == -1 {
        return false
        //return error('Cannot open directory for extracting, directory not exists')
    }
    res := C.zip_extract(zentry, path.str, 0, 0)
    return res == 0
}
*/
/*
total returns the number of all entries (files and directories) in the zip archive.

@param zip zip archive handler.

@return the return code - the number of entries on success, negative number
         (< 0) on error.
*/
pub fn (mut zentry Zip) total() ?int {
	tentry := int(C.zip_total_entries(zentry))
	if tentry == -1 {
		return error('szip: cannot count total entries')
	}
	return tentry
}