use std::str::FromStr;
use std::io::Write;

use serde::{Serialize, Deserialize};

use crate::error;
use crate::models::Entry;

#[derive(Debug, Serialize, Deserialize)]
#[serde(rename_all = "lowercase")]
pub enum Formatter {
    Text,
    Custom(String),
}

impl Formatter {
    pub fn print_formatted<W: Write>(&self, entries: Vec<Entry>, out: &mut W) -> error::Result<()> {
        match &self {
            Formatter::Text => {
                for entry in entries {
                    writeln!(out, "{:?}", entry)?;
                }
            }
            Formatter::Custom(name) => {
            }
        }

        Ok(())
    }
}

impl FromStr for Formatter {
    type Err = error::Error;

    fn from_str(s: &str) -> error::Result<Formatter> {
        let lower = s.to_lowercase();

        Ok(match &*lower {
            "text" => Formatter::Text,
            custom_format => Formatter::Custom(custom_format.into()),
        })
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::types::Time;

    #[test]
    fn test_text_output() {
        let formatter = Formatter::Text;
        let mut output = Vec::new();
        let entries = vec![
            Entry::new_sample(1, Time::new(2008, 10, 3, 12, 0, 0), Some(Time::new(2008, 10, 3, 14, 0, 0))),
            Entry::new_sample(2, Time::new(2008, 10, 3, 12, 0, 0), Some(Time::new(2008, 10, 3, 14, 0, 0))),
            Entry::new_sample(3, Time::new(2008, 10, 5, 16, 0, 0), Some(Time::new(2008, 10, 3, 18, 0, 0))),
            Entry::new_sample(4, Time::new(2008, 10, 5, 18, 0, 0), None),
        ];

        formatter.print_formatted(entries, &mut output).unwrap();

        assert_eq!(String::from_utf8_lossy(&output), "Timesheet: SpecSheet
    Day                Start      End        Duration   Notes
    Fri Oct 03, 2008   12:00:00 - 14:00:00   2:00:00    entry 1
                       16:00:00 - 18:00:00   2:00:00    entry 2
                                             4:00:00
    Sun Oct 05, 2008   16:00:00 - 18:00:00   2:00:00    entry 3
                       18:00:00 -            2:00:00    entry 4
                                             4:00:00
    -----------------------------------------------------------
    Total                                    8:00:00
");
    }
}