use crate::model::Transaction;
use chrono::NaiveDate;

pub fn parse(filename: &str) -> anyhow::Result<Vec<Transaction>> {
    let file = std::fs::File::open(filename)?;
    let mut reader = csv::ReaderBuilder::new()
        .has_headers(true)
        .from_reader(file);

    let mut transactions = Vec::new();

    for result in reader.records() {
        let record = result?;
        if record.len() >= 5 {
            // Format: "date","transaction","description","amount","balance"
            if let (Ok(date), Some(description), Ok(amount)) = (
                NaiveDate::parse_from_str(&record[0], "%Y-%m-%d"),
                record.get(2),
                record[3].parse::<f64>(),
            ) {
                let account = "Wise".to_string();
                transactions.push(Transaction::new(
                    date,
                    description.to_string(),
                    amount,
                    account,
                ));
            }
        }
    }
    Ok(transactions)
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::io::Write;
    use tempfile::NamedTempFile;

    #[test]
    fn test_wise_parser() {
        let csv_content = "\"date\",\"transaction\",\"description\",\"amount\",\"balance\"\n\"2025-05-18\",\"TRFIN\",\"Money transfer into the account (executed at 2025-05-18), FX Rate: 1.3843\",\"112239.94\",\"112239.94\"\n\"2025-05-18\",\"TRFOUT\",\"Money transfer out of the account (executed at 2025-05-18)\",\"-100000.0\",\"12239.94\"";

        let mut temp_file = NamedTempFile::new().unwrap();
        temp_file.write_all(csv_content.as_bytes()).unwrap();
        temp_file.flush().unwrap();

        let transactions = parse(temp_file.path().to_str().unwrap()).unwrap();

        assert_eq!(transactions.len(), 2);

        let first_txn = &transactions[0];
        assert_eq!(first_txn.date.format("%Y-%m-%d").to_string(), "2025-05-18");
        assert_eq!(
            first_txn.description,
            "Money transfer into the account (executed at 2025-05-18), FX Rate: 1.3843"
        );
        assert_eq!(first_txn.amount, 112239.94);
        assert_eq!(first_txn.account, "Wise");
        assert_eq!(first_txn.category, Some("Transfer".to_string()));

        let second_txn = &transactions[1];
        assert_eq!(second_txn.date.format("%Y-%m-%d").to_string(), "2025-05-18");
        assert_eq!(
            second_txn.description,
            "Money transfer out of the account (executed at 2025-05-18)"
        );
        assert_eq!(second_txn.amount, -100000.0);
        assert_eq!(second_txn.account, "Wise");
        assert_eq!(second_txn.category, Some("Transfer".to_string()));
    }
}