use std::any::TypeId;
use anyhow::Error;
use sqlx::{Encode, Postgres, Type};
use crate::part::{BindQueryBuilder, SqlPart};

pub struct SqlInsert {
    table_name: String,
    columns: Vec<(String, TypeId)>
}

impl SqlInsert {
    pub fn with_table(table_name: impl Into<String>) -> Self {
        Self {table_name: table_name.into(), columns: Vec::new()}
    }

    pub fn col<T: Encode<'static, Postgres> + Type<Postgres> + Clone + 'static>(mut self, column_name: impl Into<String>) -> Self {
        self.columns.push((column_name.into(), TypeId::of::<T>()));
        self
    }

    pub fn opt_col<T: Encode<'static, Postgres> + Type<Postgres> + Clone + 'static>(mut self, column_name: impl Into<String>) -> Self {
        self.columns.push((column_name.into(), TypeId::of::<Option<T>>()));
        self
    }

    pub fn arr_col<T: Encode<'static, Postgres> + Type<Postgres> + Clone + 'static>(mut self, column_name: impl Into<String>) -> Self {
        self.columns.push((column_name.into(), TypeId::of::<Vec<T>>()));
        self
    }

    pub fn opt_arr_col<T: Encode<'static, Postgres> + Type<Postgres> + Clone + 'static>(mut self, column_name: impl Into<String>) -> Self {
        self.columns.push((column_name.into(), TypeId::of::<Option<Vec<T>>>()));
        self
    }
}

impl SqlPart for SqlInsert {
    fn encode(&self, arg_buffer: &mut BindQueryBuilder) -> Result<(), Error> {
        arg_buffer.push("INSERT INTO ")
            .push(&self.table_name)
            .push("(");

        let mut cols = vec![];
        let mut types = vec![];
        for (column_name, column_type) in &self.columns {
            cols.push(column_name.as_str());
            types.push(column_type.clone());
        }

        let end_idx = cols.len();
        let mut i = 0;
        for col in cols {
            arg_buffer.push(col);
            if i < end_idx-1 {
                arg_buffer.push(",");
            }
            i += 1;
        }

        arg_buffer.push(") VALUES (");

        i = 0;
        for ty in types {
            unsafe {
                arg_buffer.create_bind_raw_unchecked(ty);
            }
            if i < end_idx-1 {
                arg_buffer.push(",");
            }
            i += 1
        }
        arg_buffer.push(")");
        Ok(())
    }
}