use anyhow::Result;
use clap::Command;
use std::io::{Read, Write};

use crate::config;
use crate::services::item_service::ItemService;

fn validate_save_args(cmd: &mut Command, ids: &Vec<i64>) {
    if !ids.is_empty() {
        cmd.error(
            clap::error::ErrorKind::InvalidValue,
            "ID given, you cannot supply IDs when using --save",
        )
        .exit();
    }
}

// Tee reader that writes to a writer as it is read
struct TeeReader<R: Read, W: Write> {
    reader: R,
    writer: W,
}

impl<R: Read, W: Write> Read for TeeReader<R, W> {
    fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
        let n = self.reader.read(buf)?;
        if n > 0 {
            self.writer.write_all(&buf[..n])?;
        }
        Ok(n)
    }
}

pub fn mode_save(
    cmd: &mut Command,
    settings: &config::Settings,
    ids: &mut Vec<i64>,
    tags: &mut Vec<String>,
    conn: &mut rusqlite::Connection,
    data_path: std::path::PathBuf,
) -> Result<(), anyhow::Error> {
    validate_save_args(cmd, ids);

    let item_service = ItemService::new(data_path);

    let stdin = std::io::stdin();
    let stdout = std::io::stdout();

    let tee_reader = TeeReader {
        reader: stdin.lock(),
        writer: stdout.lock(),
    };

    item_service.save_item(tee_reader, cmd, settings, tags, conn)?;

    Ok(())
}