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use serde::de::{Deserialize, Deserializer, Error, MapVisitor, SeqVisitor, Type, Visitor};
use serde::de::impls::IgnoredAny;
pub use serde_types::geometry::*;
#[derive(Clone, Debug, PartialEq)]
pub enum Geometry {
Point(Position),
MultiPoint(Vec<Position>),
LineString(LineString),
MultiLineString(Vec<LineString>),
Polygon(Polygon),
MultiPolygon(Vec<Polygon>),
}
pub type LineString = Vec<Position>;
pub type Polygon = Vec<LinearRing>;
pub type LinearRing = LineString;
impl Deserialize for Geometry {
fn deserialize<D: Deserializer>(d: &mut D) -> Result<Self, D::Error> {
struct GeometryVisitor;
impl Visitor for GeometryVisitor {
type Value = Geometry;
fn visit_map<V: MapVisitor>(&mut self, mut v: V) -> Result<Geometry, V::Error> {
enum Coordinates {
F64(f64),
Dim0(Position),
Dim1(Vec<Position>),
Dim2(Vec<Vec<Position>>),
Dim3(Vec<Vec<Vec<Position>>>),
}
impl Deserialize for Coordinates {
fn deserialize<D: Deserializer>(d: &mut D) -> Result<Self, D::Error> {
struct CoordinatesVisitor;
impl Visitor for CoordinatesVisitor {
type Value = Coordinates;
fn visit_f64<E>(&mut self, v: f64) -> Result<Coordinates, E> {
Ok(Coordinates::F64(v))
}
fn visit_i64<E>(&mut self, v: i64) -> Result<Coordinates, E> {
Ok(Coordinates::F64(v as _))
}
fn visit_u64<E>(&mut self, v: u64) -> Result<Coordinates, E> {
Ok(Coordinates::F64(v as _))
}
fn visit_seq<V: SeqVisitor>(&mut self, mut v: V) -> Result<Coordinates, V::Error> {
macro_rules! match_val {
(
$C:ident,
$($V:ident => $R:ident,)*
) => {
match v.visit()? {
Some($C::F64(v1)) => {
let v2 = match v.visit()? {
Some(val) => val,
None => return Err(V::Error::invalid_length(1)),
};
while let Some(_) = v.visit::<IgnoredAny>()? {}
v.end()?;
Ok($C::Dim0(Position(v1, v2)))
},
$(Some($C::$V(val)) => {
let mut ret = Vec::with_capacity(v.size_hint().0 + 1);
ret.push(val);
while let Some(val) = v.visit()? {
ret.push(val);
}
v.end()?;
Ok($C::$R(ret))
},)*
Some($C::Dim3(_)) => Err(V::Error::invalid_type(Type::Seq)),
None => Ok($C::Dim1(Vec::new())),
}
};
}
match_val! {
Coordinates,
Dim0 => Dim1,
Dim1 => Dim2,
Dim2 => Dim3,
}
}
}
d.deserialize_seq(CoordinatesVisitor)
}
}
let mut c = None;
use self::Geometry::*;
macro_rules! end {
() => {{
while let Some(_) = v.visit::<IgnoredAny, IgnoredAny>()? {}
v.end()?;
}};
}
while let Some(k) = v.visit_key::<String>()? {
match k.as_str() {
"type" => {
let t = v.visit_value::<String>()?;
macro_rules! match_type {
($C:ident, $($($V:ident($typ:expr))|* => $D:ident,)*) => {
match t.as_str() {
$($($typ => match c {
Some($C::$D(val)) => {
end!();
return Ok($V(val));
},
None => {
while let Some(k) = v.visit_key::<String>()? {
match k.as_str() {
"coordinates" => {
end!();
return Ok($V(v.visit_value()?));
},
_ => { v.visit_value::<IgnoredAny>()?; },
}
}
return Err(V::Error::missing_field("coordinates"));
},
_ => return Err(V::Error::custom("invalid coordinates type")),
},)*)*
s => return Err(V::Error::unknown_variant(&s)),
}
};
}
match_type! {
Coordinates,
Point("Point") => Dim0,
MultiPoint("MultiPoint") | LineString("LineString") => Dim1,
MultiLineString("MultiLineString") | Polygon("Polygon") => Dim2,
MultiPolygon("MultiPolygon") => Dim3,
}
},
"coordinates" => c = Some(v.visit_value()?),
_ => { v.visit_value::<IgnoredAny>()?; },
}
}
v.missing_field("type")
}
}
d.deserialize_map(GeometryVisitor)
}
}
#[cfg(test)]
mod tests {
use json;
use super::*;
#[test]
fn deserialize() {
assert_eq!(
Geometry::Point(Position(-75.14310264, 40.05701649)),
json::from_str("{\"coordinates\":[-75.14310264,40.05701649],\"type\":\"Point\"}").unwrap()
);
assert_eq!(
Geometry::Polygon(vec![vec![Position(2.2241006,48.8155414), Position(2.4699099,48.8155414),
Position(2.4699099,48.9021461), Position(2.2241006,48.9021461)]]),
json::from_str("{\"coordinates\":[
[[2.2241006,48.8155414],[2.4699099,48.8155414],[2.4699099,48.9021461],[2.2241006,48.9021461]]
],\"type\":\"Polygon\"}").unwrap()
);
}
}