package yaml

import (
	"io"
)

	if parser.tokens_head > 0 && len(parser.tokens) == cap(parser.tokens) {
		if parser.tokens_head != len(parser.tokens) {
			copy(parser.tokens, parser.tokens[parser.tokens_head:])
		}
		parser.tokens = parser.tokens[:len(parser.tokens)-parser.tokens_head]
		parser.tokens_head = 0
	}
	parser.tokens = append(parser.tokens, *token)
	if pos < 0 {
		return
	}
	copy(parser.tokens[parser.tokens_head+pos+1:], parser.tokens[parser.tokens_head+pos:])
	parser.tokens[parser.tokens_head+pos] = *token
}

func yaml_parser_initialize(parser *yaml_parser_t) bool {
	*parser = yaml_parser_t{
		raw_buffer: make([]byte, 0, input_raw_buffer_size),
		buffer:     make([]byte, 0, input_buffer_size),
	}
	return true
}

func yaml_parser_delete(parser *yaml_parser_t) {
	*parser = yaml_parser_t{}
}

func yaml_string_read_handler(parser *yaml_parser_t, buffer []byte) (n int, err error) {
	if parser.input_pos == len(parser.input) {
		return 0, io.EOF
	}
	n = copy(buffer, parser.input[parser.input_pos:])
	parser.input_pos += n
	return n, nil
}

func yaml_reader_read_handler(parser *yaml_parser_t, buffer []byte) (n int, err error) {
	return parser.input_reader.Read(buffer)
}

func yaml_parser_set_input_string(parser *yaml_parser_t, input []byte) {
	if parser.read_handler != nil {
		panic("must set the input source only once")
	}
	parser.read_handler = yaml_string_read_handler
	parser.input = input
	parser.input_pos = 0
}

func yaml_parser_set_input_reader(parser *yaml_parser_t, r io.Reader) {
	if parser.read_handler != nil {
		panic("must set the input source only once")
	}
	parser.read_handler = yaml_reader_read_handler
	parser.input_reader = r
}

func yaml_parser_set_encoding(parser *yaml_parser_t, encoding yaml_encoding_t) {
	if parser.encoding != yaml_ANY_ENCODING {
		panic("must set the encoding only once")
	}
	parser.encoding = encoding
}

func yaml_emitter_initialize(emitter *yaml_emitter_t) {
	*emitter = yaml_emitter_t{
		buffer:     make([]byte, output_buffer_size),
		raw_buffer: make([]byte, 0, output_raw_buffer_size),
		states:     make([]yaml_emitter_state_t, 0, initial_stack_size),
		events:     make([]yaml_event_t, 0, initial_queue_size),
		best_width: -1,
	}
}

func yaml_emitter_delete(emitter *yaml_emitter_t) {
	*emitter = yaml_emitter_t{}
}

func yaml_string_write_handler(emitter *yaml_emitter_t, buffer []byte) error {
	*emitter.output_buffer = append(*emitter.output_buffer, buffer...)
	return nil
}

func yaml_writer_write_handler(emitter *yaml_emitter_t, buffer []byte) error {
	_, err := emitter.output_writer.Write(buffer)
	return err
}

func yaml_emitter_set_output_string(emitter *yaml_emitter_t, output_buffer *[]byte) {
	if emitter.write_handler != nil {
		panic("must set the output target only once")
	}
	emitter.write_handler = yaml_string_write_handler
	emitter.output_buffer = output_buffer
}

func yaml_emitter_set_output_writer(emitter *yaml_emitter_t, w io.Writer) {
	if emitter.write_handler != nil {
		panic("must set the output target only once")
	}
	emitter.write_handler = yaml_writer_write_handler
	emitter.output_writer = w
}

func yaml_emitter_set_encoding(emitter *yaml_emitter_t, encoding yaml_encoding_t) {
	if emitter.encoding != yaml_ANY_ENCODING {
		panic("must set the output encoding only once")
	}
	emitter.encoding = encoding
}

func yaml_emitter_set_canonical(emitter *yaml_emitter_t, canonical bool) {
	emitter.canonical = canonical
}

func yaml_emitter_set_indent(emitter *yaml_emitter_t, indent int) {
	if indent < 2 || indent > 9 {
		indent = 2
	}
	emitter.best_indent = indent
}

func yaml_emitter_set_width(emitter *yaml_emitter_t, width int) {
	if width < 0 {
		width = -1
	}
	emitter.best_width = width
}

func yaml_emitter_set_unicode(emitter *yaml_emitter_t, unicode bool) {
	emitter.unicode = unicode
}

func yaml_emitter_set_break(emitter *yaml_emitter_t, line_break yaml_break_t) {
	emitter.line_break = line_break
}

func yaml_stream_start_event_initialize(event *yaml_event_t, encoding yaml_encoding_t) {
	*event = yaml_event_t{
		typ:      yaml_STREAM_START_EVENT,
		encoding: encoding,
	}
}

func yaml_stream_end_event_initialize(event *yaml_event_t) {
	*event = yaml_event_t{
		typ: yaml_STREAM_END_EVENT,
	}
}

func yaml_document_start_event_initialize(
	event *yaml_event_t,
	version_directive *yaml_version_directive_t,
	tag_directives []yaml_tag_directive_t,
	implicit bool,
) {
	*event = yaml_event_t{
		typ:               yaml_DOCUMENT_START_EVENT,
		version_directive: version_directive,
		tag_directives:    tag_directives,
		implicit:          implicit,
	}
}

func yaml_document_end_event_initialize(event *yaml_event_t, implicit bool) {
	*event = yaml_event_t{
		typ:      yaml_DOCUMENT_END_EVENT,
		implicit: implicit,
	}
}

func yaml_scalar_event_initialize(event *yaml_event_t, anchor, tag, value []byte, plain_implicit, quoted_implicit bool, style yaml_scalar_style_t) bool {
	*event = yaml_event_t{
		typ:             yaml_SCALAR_EVENT,
		anchor:          anchor,
		tag:             tag,
		value:           value,
		implicit:        plain_implicit,
		quoted_implicit: quoted_implicit,
		style:           yaml_style_t(style),
	}
	return true
}

func yaml_sequence_start_event_initialize(event *yaml_event_t, anchor, tag []byte, implicit bool, style yaml_sequence_style_t) bool {
	*event = yaml_event_t{
		typ:      yaml_SEQUENCE_START_EVENT,
		anchor:   anchor,
		tag:      tag,
		implicit: implicit,
		style:    yaml_style_t(style),
	}
	return true
}

func yaml_sequence_end_event_initialize(event *yaml_event_t) bool {
	*event = yaml_event_t{
		typ: yaml_SEQUENCE_END_EVENT,
	}
	return true
}

func yaml_mapping_start_event_initialize(event *yaml_event_t, anchor, tag []byte, implicit bool, style yaml_mapping_style_t) {
	*event = yaml_event_t{
		typ:      yaml_MAPPING_START_EVENT,
		anchor:   anchor,
		tag:      tag,
		implicit: implicit,
		style:    yaml_style_t(style),
	}
}

func yaml_mapping_end_event_initialize(event *yaml_event_t) {
	*event = yaml_event_t{
		typ: yaml_MAPPING_END_EVENT,
	}
}

func yaml_event_delete(event *yaml_event_t) {
	*event = yaml_event_t{}
}