use crate::error::AppError;
use crate::ingestion::db;
use crate::ingestion::ingestion_logic::{from_csv_row, from_json_row};
use anyhow::anyhow;
use axum::extract::multipart::MultipartError;
use axum::extract::{Extension, Json, Multipart};
use bytes::Bytes;
use sea_orm::DatabaseConnection;
use serde_json::Value;
use std::io::Cursor;

pub async fn monzo_batched_json(
    Extension(db): Extension<DatabaseConnection>,
    Json(data): Json<Vec<Vec<Value>>>,
) -> Result<&'static str, AppError> {
    let data = data
        .into_iter()
        .skip(1) // Skip the header row.
        .map(from_json_row)
        .collect::<Result<_, _>>()?;

    // We default to the main account for JSON ingestion for now.
    let account_id = db::get_account_id(&db, None).await?;
    db::insert(&db, data, account_id).await?;

    Ok("Ok")
}

async fn extract_csv_and_account_name(mut multipart: Multipart) -> Result<(Option<Bytes>, Option<String>), MultipartError> {
    let mut csv = None;
    let mut account_name = None;

    while let Some(field) = multipart.next_field().await? {
        match field.name() {
            Some("csv") => {
                csv = Some(field.bytes().await?);
            }

            Some("account_id") => {
                account_name = Some(field.text().await?);
            }

            _ => {}
        }

        if csv.is_some() && account_name.is_some() {
            break;
        }
    }

    Ok((csv, account_name))
}
pub async fn monzo_batched_csv(
    Extension(db): Extension<DatabaseConnection>,
    multipart: Multipart,
) -> Result<&'static str, AppError> {
    static CSV_MISSING_ERR_MSG: &str = "No CSV file provided. Expected a multipart request with a `csv` field containing the contents of the CSV.";

    let (csv, account_name) = extract_csv_and_account_name(multipart)
        .await
        .map_err(|e| AppError::BadRequest(anyhow!(e)))?;

    let Some(csv) = csv else {
        return Err(AppError::BadRequest(anyhow!(CSV_MISSING_ERR_MSG)));
    };

    let account_id = db::get_account_id(&db, account_name).await?;

    let csv = Cursor::new(csv);
    let mut csv = csv::Reader::from_reader(csv);
    let data = csv.records();
    let data = data
        .filter_map(|f| f.ok())
        .map(from_csv_row)
        .collect::<Result<_, _>>()?;

    db::insert(&db, data, account_id).await?;

    Ok("Ok")
}