// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package norm

import 

type normWriter struct {
	rb  reorderBuffer
	w   io.Writer
	buf []byte
}

// Write implements the standard write interface.  If the last characters are
// not at a normalization boundary, the bytes will be buffered for the next
// write. The remaining bytes will be written on close.
func ( *normWriter) ( []byte) ( int,  error) {
	// Process data in pieces to keep w.buf size bounded.
	const  = 4000

	for len() > 0 {
		// Normalize into w.buf.
		 := len()
		if  >  {
			 = 
		}
		.rb.src = inputBytes([:])
		.rb.nsrc = 
		.buf = doAppend(&.rb, .buf, 0)
		 = [:]
		 += 

		// Write out complete prefix, save remainder.
		// Note that lastBoundary looks back at most 31 runes.
		 := lastBoundary(&.rb.f, .buf)
		if  == -1 {
			 = 0
		}
		if  > 0 {
			if _,  = .w.Write(.buf[:]);  != nil {
				break
			}
			 := copy(.buf, .buf[:])
			.buf = .buf[:]
		}
	}
	return , 
}

// Close forces data that remains in the buffer to be written.
func ( *normWriter) () error {
	if len(.buf) > 0 {
		,  := .w.Write(.buf)
		if  != nil {
			return 
		}
	}
	return nil
}

// Writer returns a new writer that implements Write(b)
// by writing f(b) to w. The returned writer may use an
// internal buffer to maintain state across Write calls.
// Calling its Close method writes any buffered data to w.
func ( Form) ( io.Writer) io.WriteCloser {
	 := &normWriter{rb: reorderBuffer{}, w: }
	.rb.init(, nil)
	return 
}

type normReader struct {
	rb           reorderBuffer
	r            io.Reader
	inbuf        []byte
	outbuf       []byte
	bufStart     int
	lastBoundary int
	err          error
}

// Read implements the standard read interface.
func ( *normReader) ( []byte) (int, error) {
	for {
		if .lastBoundary-.bufStart > 0 {
			 := copy(, .outbuf[.bufStart:.lastBoundary])
			.bufStart += 
			if .lastBoundary-.bufStart > 0 {
				return , nil
			}
			return , .err
		}
		if .err != nil {
			return 0, .err
		}
		 := copy(.outbuf, .outbuf[.lastBoundary:])
		.outbuf = .outbuf[0:]
		.bufStart = 0

		,  := .r.Read(.inbuf)
		.rb.src = inputBytes(.inbuf[0:])
		.rb.nsrc, .err = , 
		if  > 0 {
			.outbuf = doAppend(&.rb, .outbuf, 0)
		}
		if  == io.EOF {
			.lastBoundary = len(.outbuf)
		} else {
			.lastBoundary = lastBoundary(&.rb.f, .outbuf)
			if .lastBoundary == -1 {
				.lastBoundary = 0
			}
		}
	}
}

// Reader returns a new reader that implements Read
// by reading data from r and returning f(data).
func ( Form) ( io.Reader) io.Reader {
	const  = 4000
	 := make([]byte, )
	 := &normReader{rb: reorderBuffer{}, r: , inbuf: }
	.rb.init(, )
	return 
}