use std::convert::TryFrom;
use std::io::Write;

use clap::ArgMatches;
use chrono::{DateTime, Utc};

use crate::database::Database;
use crate::error::{Error, Result};
use crate::editor;
use crate::commands::Command;
use crate::config::Config;
use crate::timeparse::parse_time;
use crate::old::{time_or_warning, warn_if_needed};

#[derive(Default)]
pub struct Args {
    pub at: Option<DateTime<Utc>>,
    pub note: Option<String>,
}

impl<'a> TryFrom<&'a ArgMatches<'a>> for Args {
    type Error = Error;

    fn try_from(matches: &'a ArgMatches) -> Result<Self> {
        Ok(Args {
            at: matches.value_of("at").map(|s| parse_time(s)).transpose()?,
            note: matches.value_of("note").map(|s| s.into()),
        })
    }
}

pub struct InCommand {}

impl<'a> Command<'a> for InCommand {
    type Args = Args;

    fn handle<D, O, E>(args: Args, db: &mut D, out: &mut O, err: &mut E, config: &Config, now: DateTime<Utc>) -> Result<()>
    where
        D: Database,
        O: Write,
        E: Write,
    {
        let start = args.at.unwrap_or(now);
        let sheet = db.current_sheet()?.unwrap_or_else(|| "default".into());

        if db.running_entry(&sheet)?.is_some() {
            writeln!(out, "Timer is already running for sheet '{}'", sheet)?;

            return Ok(());
        }

        let note = if let Some(note) = args.note {
            Some(note)
        } else if !config.require_note {
            None
        } else {
            Some(editor::get_string(config.note_editor.as_ref())?)
        };

        let (start, needs_warning) = time_or_warning(start, db)?;

        db.entry_insert(start, None, note.map(|n| n.trim().to_owned()), &sheet)?;

        writeln!(out, "Checked into sheet \"{}\".", sheet)?;

        warn_if_needed(err, needs_warning)?;

        Ok(())
    }
}

#[cfg(test)]
mod tests {
    use pretty_assertions::assert_eq;
    use ansi_term::Color::Yellow;
    use chrono::{TimeZone, Local};

    use crate::test_utils::PrettyString;
    use crate::database::SqliteDatabase;

    use super::*;

    #[test]
    fn handles_new_entry() {
        let mut d = SqliteDatabase::from_memory().unwrap();
        let args = Args {
            at: None,
            note: Some("hola".into()),
        };
        let mut out = Vec::new();
        let mut err = Vec::new();
        let now = Utc::now();

        d.init().unwrap();

        assert_eq!(d.entries_full(None, None).unwrap().len(), 0);

        InCommand::handle(args, &mut d, &mut out, &mut err, &Default::default(), now).unwrap();

        let e = d.entries_full(None, None).unwrap().into_iter().next().unwrap();

        assert_eq!(e.note, Some("hola".into()));
        assert_eq!(e.start, now);
        assert_eq!(e.end, None);
        assert_eq!(e.sheet, "default".to_owned());

        assert_eq!(PrettyString(&String::from_utf8_lossy(&out)), PrettyString("Checked into sheet \"default\".\n"));
        assert_eq!(PrettyString(&String::from_utf8_lossy(&err)), PrettyString(""));
    }

    #[test]
    fn test_handles_already_running_entry() {
        let mut d = SqliteDatabase::from_memory().unwrap();
        let args = Args {
            at: None,
            note: Some("hola".into()),
        };
        let mut out = Vec::new();
        let mut err = Vec::new();
        let now = Utc::now();

        d.init().unwrap();

        d.entry_insert(now, None, None, "default".into()).unwrap();

        assert_eq!(d.entries_full(None, None).unwrap().len(), 1);

        InCommand::handle(args, &mut d, &mut out, &mut err, &Default::default(), Utc::now()).unwrap();

        assert_eq!(d.entries_full(None, None).unwrap().len(), 1);

        assert_eq!(
            PrettyString(&String::from_utf8_lossy(&out)),
            PrettyString("Timer is already running for sheet 'default'\n")
        );
    }

    #[test]
    fn no_note_and_no_mandatory_leaves_none() {
        let mut d = SqliteDatabase::from_memory().unwrap();
        let args = Default::default();
        let mut out = Vec::new();
        let mut err = Vec::new();
        let now = Utc::now();
        let config = Config {
            require_note: false,
            ..Default::default()
        };

        d.init().unwrap();

        assert_eq!(d.entries_full(None, None).unwrap().len(), 0);

        InCommand::handle(args, &mut d, &mut out, &mut err, &config, now).unwrap();

        let e = d.entries_full(None, None).unwrap().into_iter().next().unwrap();

        assert_eq!(e.note, None);
        assert_eq!(e.start, now);
        assert_eq!(e.end, None);
        assert_eq!(e.sheet, "default".to_owned());
    }

    #[test]
    fn warns_if_old_database() {
        let mut d = SqliteDatabase::from_memory().unwrap();
        let args = Args {
            at: None,
            note: Some("hola".into()),
        };
        let mut out = Vec::new();
        let mut err = Vec::new();
        let now = Utc::now();

        d.init_old().unwrap();

        assert_eq!(d.entries_full(None, None).unwrap().len(), 0);

        InCommand::handle(args, &mut d, &mut out, &mut err, &Default::default(), now).unwrap();

        let e = d.entries_full(None, None).unwrap().into_iter().next().unwrap();

        assert_eq!(e.note, Some("hola".into()));
        assert_eq!(e.start, Utc.from_utc_datetime(&now.with_timezone(&Local).naive_local()));
        assert_eq!(e.end, None);
        assert_eq!(e.sheet, "default".to_owned());

        assert_eq!(PrettyString(&String::from_utf8_lossy(&out)), PrettyString("Checked into sheet \"default\".\n"));
        assert_eq!(PrettyString(&String::from_utf8_lossy(&err)), PrettyString(&format!(
            "{} You are using the old timetrap format, it is advised that \
            you update your database using t migrate\n",
            Yellow.bold().paint("[WARNING]"))));
    }

    #[test]
    fn notes_are_trimmed() {
        let mut d = SqliteDatabase::from_memory().unwrap();
        let args = Args {
            at: None,
            note: Some("hola\n".into()),
        };
        let mut out = Vec::new();
        let mut err = Vec::new();
        let now = Utc::now();

        d.init().unwrap();

        assert_eq!(d.entries_full(None, None).unwrap().len(), 0);

        InCommand::handle(args, &mut d, &mut out, &mut err, &Default::default(), now).unwrap();

        let e = d.entries_full(None, None).unwrap().into_iter().next().unwrap();

        assert_eq!(e.note, Some("hola".into()));
        assert_eq!(e.start, now);
        assert_eq!(e.end, None);
        assert_eq!(e.sheet, "default".to_owned());

        assert_eq!(PrettyString(&String::from_utf8_lossy(&out)), PrettyString("Checked into sheet \"default\".\n"));
        assert_eq!(PrettyString(&String::from_utf8_lossy(&err)), PrettyString(""));
    }
}