// Libraries
use std::fs::File;
use std::io::{self, Result};

use csv::{self, StringRecord};
use walkdir::WalkDir;

// Structures
pub struct Packager {
    directory: String,
    file_out: String,
}

// Implementations
impl Packager {
    // Constructors
    pub fn new(directory: String, file_out: String) -> Self {
        Self {
            directory,
            file_out,
        }
    }

    // Functions
    fn read_csv(&self, path: &str) -> Result<Vec<StringRecord>> {
        // Opening the File & Reading
        let file = File::open(path)?;
        let mut rdr = csv::Reader::from_reader(file);

        // Creating a list of string records
        let mut result: Vec<StringRecord> = Vec::new();

        // Iterate through records
        for record in rdr.records() {
            result.push(record?);
        }

        // Ok!
        Ok(result)
    }
    fn save(&self, records: Vec<StringRecord>) -> Result<()> {
        // Writing to the path we want
        let mut writer = csv::Writer::from_path(&self.file_out)?;

        // Creating the Header
        writer.write_record(&["Date", "Description", "Amount"])?;

        // Adding all Records
        for record in &records {
            writer.write_record(record)?;
        }

        // Flushing!!
        writer.flush()?;

        // Ok!!
        Ok(())
    }

    pub fn start(&self) -> Result<()> {
        // Holding all Records
        let mut records: Vec<StringRecord> = Vec::new();

        // Using WalkDir to go through the Directory
        for entry in WalkDir::new(&self.directory) {
            // Reference the Path
            let entry = entry?;
            let path = entry.path();

            // Is it a file?
            if !path.is_file() {
                continue;
            }

            // Reading the CSV from the Path
            let file = self.read_csv(path.to_str().unwrap())?;

            // Adding it to the record list
            records.extend(file);
        }

        // Saving the Records
        self.save(records)?;

        // Ok!!
        Ok(())
    }
}