//! # Plist
//!
//! A rusty plist parser.
//!
//! ## Usage
//!
//! Put this in your `Cargo.toml`:
//!
//! ```toml
//! [dependencies]
//! plist = "0.0.11"
//! ```
//!
//! And put this in your crate root:
//!
//! ```rust
//! extern crate plist;
//! ```
//!
//! ## Examples
//!
//! ```rust ignore
//! use plist::Plist;
//! use std::fs::File;
//!
//! let file = File::open("tests/data/xml.plist").unwrap();
//! let plist = Plist::read(file).unwrap();
//!
//! match plist {
//!     Plist::Array(_array) => (),
//!     _ => ()
//! }
//!
//! ```
//!
//!

extern crate byteorder;
extern crate chrono;
extern crate rustc_serialize;
extern crate xml as xml_rs;

pub mod binary;
pub mod xml;
mod builder;

use chrono::{DateTime, UTC};
use chrono::format::ParseError as ChronoParseError;
use std::collections::BTreeMap;
use std::io::{Read, Seek, SeekFrom};
use std::io::Error as IoError;

#[derive(Clone, Debug, PartialEq)]
pub enum Plist {
    Array(Vec<Plist>),
    Dictionary(BTreeMap<String, Plist>),
    Boolean(bool),
    Data(Vec<u8>),
    Date(DateTime<UTC>),
    Real(f64),
    Integer(i64),
    String(String),
}

use rustc_serialize::base64::{STANDARD, ToBase64};
use rustc_serialize::json::Json as RustcJson;

impl Plist {
    pub fn read<R: Read + Seek>(reader: R) -> Result<Plist, ()> {
        let reader = EventReader::new(reader);
        Plist::from_events(reader)
    }

    pub fn from_events<T>(events: T) -> Result<Plist, ()>
        where T: IntoIterator<Item = ReadResult<PlistEvent>>
    {
        let iter = events.into_iter();
        let builder = builder::Builder::new(iter);

        match builder.build() {
            Ok(plist) => Ok(plist),
            Err(_) => Err(()),
        }
    }

    pub fn into_events(self) -> Vec<PlistEvent> {
        let mut events = Vec::new();
        self.into_events_inner(&mut events);
        events
    }

    fn into_events_inner(self, events: &mut Vec<PlistEvent>) {
        match self {
            Plist::Array(array) => {
                events.push(PlistEvent::StartArray(Some(array.len() as u64)));
                for value in array.into_iter() {
                    value.into_events_inner(events);
                }
                events.push(PlistEvent::EndArray);
            }
            Plist::Dictionary(dict) => {
                events.push(PlistEvent::StartDictionary(Some(dict.len() as u64)));
                for (key, value) in dict.into_iter() {
                    events.push(PlistEvent::StringValue(key));
                    value.into_events_inner(events);
                }
                events.push(PlistEvent::EndDictionary);
            }
            Plist::Boolean(value) => events.push(PlistEvent::BooleanValue(value)),
            Plist::Data(value) => events.push(PlistEvent::DataValue(value)),
            Plist::Date(value) => events.push(PlistEvent::DateValue(value)),
            Plist::Real(value) => events.push(PlistEvent::RealValue(value)),
            Plist::Integer(value) => events.push(PlistEvent::IntegerValue(value)),
            Plist::String(value) => events.push(PlistEvent::StringValue(value)),
        }
    }

    pub fn into_rustc_serialize_json(self) -> RustcJson {
        match self {
            Plist::Array(value) => {
                RustcJson::Array(value.into_iter().map(|p| p.into_rustc_serialize_json()).collect())
            }
            Plist::Dictionary(value) => {
                RustcJson::Object(value.into_iter()
                                       .map(|(k, v)| (k, v.into_rustc_serialize_json()))
                                       .collect())
            }
            Plist::Boolean(value) => RustcJson::Boolean(value),
            Plist::Data(value) => RustcJson::String(value.to_base64(STANDARD)),
            Plist::Date(value) => RustcJson::String(value.to_rfc3339()),
            Plist::Real(value) => RustcJson::F64(value),
            Plist::Integer(value) => RustcJson::I64(value),
            Plist::String(value) => RustcJson::String(value),
        }
    }
}

/// An encoding of a plist as a flat structure.
///
/// Output by the event readers.
///
/// Dictionary keys and values are represented as pairs of values e.g.:
///
/// ```ignore rust
/// StartDictionary
/// StringValue("Height") // Key
/// RealValue(181.2)      // Value
/// StringValue("Age")    // Key
/// IntegerValue(28)      // Value
/// EndDictionary
/// ```
#[derive(Clone, Debug, PartialEq)]
pub enum PlistEvent {
    StartPlist,
    EndPlist,

    StartArray(Option<u64>),
    EndArray,

    StartDictionary(Option<u64>),
    EndDictionary,

    BooleanValue(bool),
    DataValue(Vec<u8>),
    DateValue(DateTime<UTC>),
    IntegerValue(i64),
    RealValue(f64),
    StringValue(String),
}

pub type ReadResult<T> = Result<T, ReadError>;

#[derive(Debug)]
pub enum ReadError {
    InvalidData,
    UnexpectedEof,
    UnsupportedType,
    Io(IoError),
}

impl From<IoError> for ReadError {
    fn from(io_error: IoError) -> ReadError {
        ReadError::Io(io_error)
    }
}

impl From<ChronoParseError> for ReadError {
    fn from(_: ChronoParseError) -> ReadError {
        ReadError::InvalidData
    }
}

pub struct EventReader<R: Read + Seek>(EventReaderInner<R>);

enum EventReaderInner<R: Read + Seek> {
    Uninitialized(Option<R>),
    Xml(xml::EventReader<R>),
    Binary(binary::EventReader<R>),
}

impl<R: Read + Seek> EventReader<R> {
    pub fn new(reader: R) -> EventReader<R> {
        EventReader(EventReaderInner::Uninitialized(Some(reader)))
    }

    fn is_binary(reader: &mut R) -> Result<bool, IoError> {
        try!(reader.seek(SeekFrom::Start(0)));
        let mut magic = [0; 8];
        try!(reader.read(&mut magic));
        try!(reader.seek(SeekFrom::Start(0)));

        Ok(if &magic == b"bplist00" {
            true
        } else {
            false
        })
    }
}

impl<R: Read + Seek> Iterator for EventReader<R> {
    type Item = ReadResult<PlistEvent>;

    fn next(&mut self) -> Option<ReadResult<PlistEvent>> {
        let mut reader = match self.0 {
            EventReaderInner::Xml(ref mut parser) => return parser.next(),
            EventReaderInner::Binary(ref mut parser) => return parser.next(),
            EventReaderInner::Uninitialized(ref mut reader) => reader.take().unwrap(),
        };

        let event_reader = match EventReader::is_binary(&mut reader) {
            Ok(true) => EventReaderInner::Binary(binary::EventReader::new(reader)),
            Ok(false) => EventReaderInner::Xml(xml::EventReader::new(reader)),
            Err(err) => {
                ::std::mem::replace(&mut self.0, EventReaderInner::Uninitialized(Some(reader)));
                return Some(Err(ReadError::Io(err)));
            }
        };

        ::std::mem::replace(&mut self.0, event_reader);

        self.next()
    }
}