microrm/microrm/src/model/load.rs

use serde::de::Visitor;

use rusqlite::Row;

pub struct RowDeserializer<'de> {
    row: &'de Row<'de>,
    col_index: usize,
}

impl<'de> RowDeserializer<'de> {
    pub fn from_row(row: &'de Row) -> Self {
        // we skip the rowid by starting at index 1
        Self { row, col_index: 1 }
    }
}

impl<'de, 'a> serde::de::Deserializer<'de> for &'a mut RowDeserializer<'de> {
    type Error = super::ModelError;

    fn deserialize_any<V: Visitor<'de>>(self, _v: V) -> Result<V::Value, Self::Error> {
        todo!()
    }

    fn deserialize_bool<V: Visitor<'de>>(self, v: V) -> Result<V::Value, Self::Error> {
        let res = v.visit_bool(self.row.get(self.col_index)?);
        self.col_index += 1;
        res
    }

    fn deserialize_i8<V: Visitor<'de>>(self, v: V) -> Result<V::Value, Self::Error> {
        let res = v.visit_i8(self.row.get(self.col_index)?);
        self.col_index += 1;
        res
    }

    fn deserialize_i16<V: Visitor<'de>>(self, v: V) -> Result<V::Value, Self::Error> {
        let res = v.visit_i16(self.row.get(self.col_index)?);
        self.col_index += 1;
        res
    }

    fn deserialize_i32<V: Visitor<'de>>(self, v: V) -> Result<V::Value, Self::Error> {
        let res = v.visit_i32(self.row.get(self.col_index)?);
        self.col_index += 1;
        res
    }

    fn deserialize_i64<V: Visitor<'de>>(self, v: V) -> Result<V::Value, Self::Error> {
        let res = v.visit_i64(self.row.get(self.col_index)?);
        self.col_index += 1;
        res
    }

    fn deserialize_string<V: Visitor<'de>>(self, v: V) -> Result<V::Value, Self::Error> {
        let res = v.visit_string(self.row.get(self.col_index)?);
        self.col_index += 1;
        res
    }

    fn deserialize_struct<V: Visitor<'de>>(
        self,
        _name: &'static str,
        _fields: &'static [&'static str],
        v: V,
    ) -> Result<V::Value, Self::Error> {
        v.visit_seq(self)
    }

    serde::forward_to_deserialize_any! {
        i128 u8 u16 u32 u64 u128 f32 f64 char str
        bytes byte_buf option unit unit_struct newtype_struct seq tuple
        tuple_struct map enum identifier ignored_any
    }
}

impl<'de> serde::de::SeqAccess<'de> for RowDeserializer<'de> {
    type Error = super::ModelError;

    fn next_element_seed<T: serde::de::DeserializeSeed<'de>>(
        &mut self,
        seed: T,
    ) -> Result<Option<T::Value>, Self::Error> {
        seed.deserialize(self).map(Some)
    }
}