use crate::db::format_number;
use crate::models::InvoiceSeries;
use crate::AppState;
use rusqlite::{params, Row};
use tauri::State;

fn map_series(row: &Row) -> rusqlite::Result<InvoiceSeries> {
    let prefix: String = row.get(1)?;
    let padding: i64 = row.get(2)?;
    let next_number: i64 = row.get(3)?;
    Ok(InvoiceSeries {
        id: row.get(0)?,
        next_invoice_number: format_number(&prefix, padding, next_number),
        prefix,
        padding,
        next_number,
        is_active: row.get::<_, i64>(4)? != 0,
        created_at: row.get(5)?,
    })
}

const SERIES_SELECT: &str =
    "SELECT id, prefix, padding, next_number, is_active, created_at FROM invoice_series";

#[tauri::command]
pub fn get_active_series(state: State<AppState>) -> Result<Option<InvoiceSeries>, String> {
    let conn = state.db.lock().map_err(|e| e.to_string())?;
    let mut stmt = conn
        .prepare(&format!(
            "{} WHERE is_active = 1 ORDER BY id DESC LIMIT 1",
            SERIES_SELECT
        ))
        .map_err(|e| e.to_string())?;
    let mut rows = stmt.query_map([], map_series).map_err(|e| e.to_string())?;
    match rows.next() {
        Some(r) => Ok(Some(r.map_err(|e| e.to_string())?)),
        None => Ok(None),
    }
}

#[tauri::command]
pub fn list_series(state: State<AppState>) -> Result<Vec<InvoiceSeries>, String> {
    let conn = state.db.lock().map_err(|e| e.to_string())?;
    let mut stmt = conn
        .prepare(&format!("{} ORDER BY id DESC", SERIES_SELECT))
        .map_err(|e| e.to_string())?;
    let rows = stmt
        .query_map([], map_series)
        .map_err(|e| e.to_string())?
        .collect::<rusqlite::Result<Vec<_>>>()
        .map_err(|e| e.to_string())?;
    Ok(rows)
}

/// Deactivates the current series and starts a fresh one, resetting the counter to 1.
#[tauri::command]
pub fn start_new_series(
    state: State<AppState>,
    prefix: String,
    padding: i64,
) -> Result<InvoiceSeries, String> {
    let prefix = prefix.trim().to_string();
    if prefix.is_empty() {
        return Err("Series prefix cannot be empty".into());
    }
    let padding = padding.clamp(1, 8);
    let conn = state.db.lock().map_err(|e| e.to_string())?;
    conn.execute("UPDATE invoice_series SET is_active = 0", [])
        .map_err(|e| e.to_string())?;
    conn.execute(
        "INSERT INTO invoice_series (prefix, padding, next_number, is_active, created_at)
         VALUES (?1, ?2, 1, 1, ?3)",
        params![prefix, padding, chrono::Utc::now().to_rfc3339()],
    )
    .map_err(|e| e.to_string())?;
    let id = conn.last_insert_rowid();
    conn.query_row(
        &format!("{} WHERE id = ?1", SERIES_SELECT),
        params![id],
        map_series,
    )
    .map_err(|e| e.to_string())
}