use crate::db::Database;
use crate::models::{NewTransaction, TransactionType};
use std::path::Path;

pub fn import_csv(db: &Database, path: &Path, merge: bool) -> Result<usize, Box<dyn std::error::Error>> {
    if !merge {
        db.reset_all_data()?;
    }

    let mut reader = csv::Reader::from_path(path)?;
    let mut count = 0;

    for result in reader.records() {
        let record = result?;
        if record.len() < 6 {
            continue;
        }
        let date_str = &record[0];
        let type_str = &record[1];
        let category_name = &record[2];
        let amount: f64 = match record[3].parse() {
            Ok(v) => v,
            Err(_) => continue,
        };
        let currency = &record[4];
        let exchange_rate: f64 = match record[5].parse() {
            Ok(v) => v,
            Err(_) => 1.0,
        };
        let note = if record.len() > 6 && !record[6].is_empty() {
            Some(record[6].to_string())
        } else {
            None
        };
        let payee = if record.len() > 7 && !record[7].is_empty() {
            Some(record[7].to_string())
        } else {
            None
        };

        let txn_type = match type_str.to_lowercase().as_str() {
            "expense" => TransactionType::Expense,
            "income" => TransactionType::Income,
            _ => continue,
        };

        let categories = db.list_categories(Some(txn_type))?;
        let category_id = match categories.iter().find(|c| c.name == category_name) {
            Some(c) => c.id,
            None => continue,
        };

        let date = chrono::NaiveDate::parse_from_str(date_str, "%Y-%m-%d")?;

        if merge && db.find_duplicate_transaction(amount, txn_type, category_id, date)? {
            continue;
        }

        let new_txn = NewTransaction {
            amount,
            transaction_type: txn_type,
            category_id,
            currency: currency.to_string(),
            exchange_rate,
            note,
            date,
            recurring_id: None,
            payee,
        };
        db.insert_transaction(&new_txn)?;
        count += 1;
    }

    Ok(count)
}