use std::collections::HashMap;

use diesel::{
    pg::{Pg,
    row::{NamedRow, Row},
    QueryableByName,
};

/// Internally a HashMap mapping field names to a custom sum type capable of
/// deserializing common SQL types. This allows Diesel to load rows without a
/// hard-coded structure.
pub struct FlexiRow {
    internal: HashMap<String, FlexiField>,
}

/// Sum type representing a range of SQL data types.
pub enum FlexiField {
    Text(String),
    Int(i32),
    Unknown,
}

impl QueryableByName<Pg> for FlexiRow {
    fn build<'a>(row: &impl NamedRow<'a, Pg>) -> diesel::deserialize::Result<Self> {
        let mut hm: HashMap<String, FlexiField> = HashMap::new();
        for i in 0..row.field_count() {
            if let Some(field) = diesel::row::Row::<'a, Pg>::get(&row, i) {
                let name = field.field_name().or("Unnamed");
            }
        }
        diesel::deserialize::Result::Ok(FlexiRow { internal: hm })
    }
}