use common::XmlVersion;

use reader::events::XmlEvent;
use reader::lexer::Token;

use super::{
    Result, PullParser, State, DeclarationSubstate, QualifiedNameTarget,
    DEFAULT_VERSION, DEFAULT_ENCODING
};

impl PullParser {
    // TODO: remove redundancy via macros or extra methods
    pub fn inside_declaration(&mut self, t: Token, s: DeclarationSubstate) -> Option<Result> {
        macro_rules! unexpected_token(
            ($this:expr; $t:expr) => (Some($this.error(format!("Unexpected token inside XML declaration: {}", $t))));
            ($t:expr) => (unexpected_token!(self; $t));
        );

        #[inline]
        fn emit_start_document(this: &mut PullParser) -> Option<Result> {
            this.parsed_declaration = true;
            let version = this.data.take_version();
            let encoding = this.data.take_encoding();
            let standalone = this.data.take_standalone();
            this.into_state_emit(State::OutsideTag, Ok(XmlEvent::StartDocument {
                version: version.unwrap_or(DEFAULT_VERSION),
                encoding: encoding.unwrap_or(DEFAULT_ENCODING.into()),
                standalone: standalone
            }))
        }

        match s {
            DeclarationSubstate::BeforeVersion => match t {
                Token::Whitespace(_) => None,  // continue
                Token::Character('v') => self.into_state_continue(State::InsideDeclaration(DeclarationSubstate::InsideVersion)),
                _ => unexpected_token!(t)
            },

            DeclarationSubstate::InsideVersion => self.read_qualified_name(t, QualifiedNameTarget::AttributeNameTarget, |this, token, name| {
                match &name.local_name[..] {
                    "ersion" if name.namespace.is_none() =>
                        this.into_state_continue(State::InsideDeclaration(
                            if token == Token::EqualsSign {
                                DeclarationSubstate::InsideVersionValue
                            } else {
                                DeclarationSubstate::AfterVersion
                            }
                        )),
                    _ => unexpected_token!(this; name)
                }
            }),

            DeclarationSubstate::AfterVersion => match t {
                Token::Whitespace(_) => None,
                Token::EqualsSign => self.into_state_continue(State::InsideDeclaration(DeclarationSubstate::InsideVersionValue)),
                _ => unexpected_token!(t)
            },

            DeclarationSubstate::InsideVersionValue => self.read_attribute_value(t, |this, value| {
                this.data.version = match &value[..] {
                    "1.0" => Some(XmlVersion::Version10),
                    "1.1" => Some(XmlVersion::Version11),
                    _     => None
                };
                if this.data.version.is_some() {
                    this.into_state_continue(State::InsideDeclaration(DeclarationSubstate::AfterVersionValue))
                } else {
                    Some(self_error!(this; "Unexpected XML version value: {}", value))
                }
            }),

            DeclarationSubstate::AfterVersionValue => match t {
                Token::Whitespace(_) => None,  // skip whitespace
                Token::Character('e') => self.into_state_continue(State::InsideDeclaration(DeclarationSubstate::InsideEncoding)),
                Token::Character('s') => self.into_state_continue(State::InsideDeclaration(DeclarationSubstate::InsideStandaloneDecl)),
                Token::ProcessingInstructionEnd => emit_start_document(self),
                _ => unexpected_token!(t)
            },

            DeclarationSubstate::InsideEncoding => self.read_qualified_name(t, QualifiedNameTarget::AttributeNameTarget, |this, token, name| {
                match &name.local_name[..] {
                    "ncoding" if name.namespace.is_none() =>
                        this.into_state_continue(State::InsideDeclaration(
                            if token == Token::EqualsSign { DeclarationSubstate::InsideEncodingValue } else { DeclarationSubstate::AfterEncoding }
                        )),
                    _ => unexpected_token!(this; name)
                }
            }),

            DeclarationSubstate::AfterEncoding => match t {
                Token::Whitespace(_) => None,
                Token::EqualsSign => self.into_state_continue(State::InsideDeclaration(DeclarationSubstate::InsideEncodingValue)),
                _ => unexpected_token!(t)
            },

            DeclarationSubstate::InsideEncodingValue => self.read_attribute_value(t, |this, value| {
                this.data.encoding = Some(value);
                this.into_state_continue(State::InsideDeclaration(DeclarationSubstate::BeforeStandaloneDecl))
            }),

            DeclarationSubstate::BeforeStandaloneDecl => match t {
                Token::Whitespace(_) => None,  // skip whitespace
                Token::Character('s') => self.into_state_continue(State::InsideDeclaration(DeclarationSubstate::InsideStandaloneDecl)),
                Token::ProcessingInstructionEnd => emit_start_document(self),
                _ => unexpected_token!(t)
            },

            DeclarationSubstate::InsideStandaloneDecl => self.read_qualified_name(t, QualifiedNameTarget::AttributeNameTarget, |this, token, name| {
                match &name.local_name[..] {
                    "tandalone" if name.namespace.is_none() =>
                        this.into_state_continue(State::InsideDeclaration(
                            if token == Token::EqualsSign {
                                DeclarationSubstate::InsideStandaloneDeclValue
                            } else {
                                DeclarationSubstate::AfterStandaloneDecl
                            }
                        )),
                    _ => unexpected_token!(this; name)
                }
            }),

            DeclarationSubstate::AfterStandaloneDecl => match t {
                Token::Whitespace(_) => None,
                Token::EqualsSign => self.into_state_continue(State::InsideDeclaration(DeclarationSubstate::InsideStandaloneDeclValue)),
                _ => unexpected_token!(t)
            },

            DeclarationSubstate::InsideStandaloneDeclValue => self.read_attribute_value(t, |this, value| {
                let standalone = match &value[..] {
                    "yes" => Some(true),
                    "no"  => Some(false),
                    _     => None
                };
                if standalone.is_some() {
                    this.data.standalone = standalone;
                    this.into_state_continue(State::InsideDeclaration(DeclarationSubstate::AfterStandaloneDeclValue))
                } else {
                    Some(self_error!(this; "Invalid standalone declaration value: {}", value))
                }
            }),

            DeclarationSubstate::AfterStandaloneDeclValue => match t {
                Token::Whitespace(_) => None,  // skip whitespace
                Token::ProcessingInstructionEnd => emit_start_document(self),
                _ => unexpected_token!(t)
            }
        }
    }

}