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

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

use crate::error::{Result, Error};
use crate::database::Database;
use crate::formatters::Formatter;
use crate::config::Config;
use crate::timeparse::parse_time;
use crate::regex::parse_regex;
use crate::old::{entries_or_warning, time_or_warning, warn_if_needed};

use super::Command;

// ----------------------------------------------------------------
// Things that are general to all commands that display in some way
// ----------------------------------------------------------------

pub enum Sheet {
    All,
    Full,
    Sheet(String),
}

impl FromStr for Sheet {
    type Err = Error;

    fn from_str(name: &str) -> Result<Sheet> {
        Ok(match name {
            "all" => Sheet::All,
            "full" => Sheet::Full,
            name => Sheet::Sheet(name.into()),
        })
    }
}

#[allow(clippy::too_many_arguments)]
pub fn entries_for_display<D, O, E>(
    start: Option<DateTime<Utc>>, end: Option<DateTime<Utc>>,
    sheet: Option<Sheet>, db: &mut D, out: &mut O, err: &mut E,
    format: Formatter, ids: bool, grep: Option<Regex>,
    now: DateTime<Utc>,
) -> Result<()>
where
    D: Database,
    O: Write,
    E: Write,
{
    let start = start.map(|s| time_or_warning(s, db)).transpose()?.map(|s| s.0);
    let end = end.map(|e| time_or_warning(e, db)).transpose()?.map(|e| e.0);

    let mut entries = match sheet {
        Some(Sheet::All) => db.entries_all_visible(start, end)?,
        Some(Sheet::Full) => db.entries_full(start, end)?,
        Some(Sheet::Sheet(name)) => db.entries_by_sheet(&name, start, end)?,
        None => {
            let current_sheet = db.current_sheet()?.unwrap_or_else(|| "default".into());

            db.entries_by_sheet(&current_sheet, start, end)?
        }
    };

    if let Some(re) = grep {
        entries.retain(|e| re.is_match(&e.note.clone().unwrap_or_else(String::new)));
    }

    let (entries, needs_warning) = entries_or_warning(entries, db)?;

    format.print_formatted(
        entries,
        out,
        now,
        ids,
    )?;

    warn_if_needed(err, needs_warning)?;

    Ok(())
}

// ------------------------------------
// The actual implementation of display
// ------------------------------------

#[derive(Default)]
pub struct Args {
    ids: bool,
    start: Option<DateTime<Utc>>,
    end: Option<DateTime<Utc>>,
    format: Formatter,
    grep: Option<Regex>,
    sheet: Option<Sheet>,
}

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

    fn try_from(matches: &'a ArgMatches) -> Result<Args> {
        Ok(Args {
            ids: matches.is_present("ids"),
            start: matches.value_of("start").map(|s| parse_time(s)).transpose()?,
            end: matches.value_of("end").map(|s| parse_time(s)).transpose()?,
            format: matches.value_of("format").unwrap().parse()?,
            grep: matches.value_of("grep").map(parse_regex).transpose()?,
            sheet: matches.value_of("sheet").map(|s| s.parse()).transpose()?,
        })
    }
}

pub struct DisplayCommand { }

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

    fn handle<D, O, E>(args: Self::Args, db: &mut D, out: &mut O, err: &mut E, _config: &Config, now: DateTime<Utc>) -> Result<()>
    where
        D: Database,
        O: Write,
        E: Write,
    {
        entries_for_display(args.start, args.end, args.sheet, db, out, err, args.format, args.ids, args.grep, now)
    }
}

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

    use crate::database::SqliteDatabase;
    use crate::test_utils::Ps;

    use super::*;

    #[test]
    fn display_as_local_time_if_previous_version() {
        std::env::set_var("TZ", "CST+6");
        let args = Default::default();
        let mut db = SqliteDatabase::from_path("assets/test_old_db.db").unwrap();
        let mut out = Vec::new();
        let mut err = Vec::new();
        let config = Default::default();

        DisplayCommand::handle(args, &mut db, &mut out, &mut err, &config, Utc::now()).unwrap();

        assert_eq!(Ps(&String::from_utf8_lossy(&out)), Ps("Timesheet: default
    Day                Start      End        Duration Notes
    Tue Jun 29, 2021   06:26:49 - 07:26:52    1:00:03 lets do some rust
                                              1:00:03
-----------------------------------------------------------------------
    Total                                     1:00:03
"));

        assert_eq!(
            String::from_utf8_lossy(&err),
            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 filter_by_start() {
        let args = Args {
            format: Formatter::Csv,
            start: Some(Utc.ymd(2021, 6, 30).and_hms(10, 5, 0)),
            ..Default::default()
        };
        let mut db = SqliteDatabase::from_memory().unwrap();
        let mut out = Vec::new();
        let mut err = Vec::new();
        let config = Default::default();

        db.init().unwrap();

        db.entry_insert(Utc.ymd(2021, 6, 30).and_hms(10, 0, 0), None, Some("hola".into()), "default".into()).unwrap();
        db.entry_insert(Utc.ymd(2021, 6, 30).and_hms(10, 10, 0), None, Some("hola".into()), "default".into()).unwrap();

        DisplayCommand::handle(args, &mut db, &mut out, &mut err, &config, Utc::now()).unwrap();

        assert_eq!(Ps(&String::from_utf8_lossy(&out)), Ps("start,end,note,sheet
2021-06-30T10:10:00.000000Z,,hola,default
"));

        assert_eq!(
            String::from_utf8_lossy(&err),
            String::new(),
        );
    }

    #[test]
    fn filter_by_match() {
        let mut db = SqliteDatabase::from_memory().unwrap();
        let mut out = Vec::new();
        let mut err = Vec::new();

        db.init().unwrap();

        db.entry_insert(Utc.ymd(2021, 6, 30).and_hms(10, 0, 0), None, Some("hola".into()), "default".into()).unwrap();
        db.entry_insert(Utc.ymd(2021, 6, 30).and_hms(10, 10, 0), None, Some("adios".into()), "default".into()).unwrap();

        entries_for_display(None, None, None, &mut db, &mut out, &mut err, Formatter::Csv, true, Some("io".parse().unwrap()), Utc::now()).unwrap();

        assert_eq!(Ps(&String::from_utf8_lossy(&out)), Ps("id,start,end,note,sheet
2,2021-06-30T10:10:00.000000Z,,adios,default
"));

        assert_eq!(
            String::from_utf8_lossy(&err),
            String::new(),
        );
    }

    #[test]
    fn entries_are_grouped_despite_database() {
        let args = Args {
            sheet: Some(Sheet::All),
            ..Default::default()
        };
        let mut db = SqliteDatabase::from_memory().unwrap();
        let mut out = Vec::new();
        let mut err = Vec::new();
        let config = Default::default();
        std::env::set_var("TZ", "CST+6");

        db.init().unwrap();

        db.entry_insert(Utc.ymd(2021, 6, 30).and_hms(10, 0, 0), Some(Utc.ymd(2021, 6, 30).and_hms(11, 0, 0)), None, "sheet1".into()).unwrap();
        db.entry_insert(Utc.ymd(2021, 6, 30).and_hms(11, 0, 0), Some(Utc.ymd(2021, 6, 30).and_hms(12, 0, 0)), None, "sheet2".into()).unwrap();
        db.entry_insert(Utc.ymd(2021, 6, 30).and_hms(12, 0, 0), Some(Utc.ymd(2021, 6, 30).and_hms(13, 0, 0)), None, "sheet1".into()).unwrap();

        DisplayCommand::handle(args, &mut db, &mut out, &mut err, &config, Utc::now()).unwrap();

        assert_eq!(Ps(&String::from_utf8_lossy(&out)), Ps("Timesheet: sheet1
    Day                Start      End        Duration Notes
    Wed Jun 30, 2021   04:00:00 - 05:00:00    1:00:00
                       06:00:00 - 07:00:00    1:00:00
                                              2:00:00
-----------------------------------------------------------
    Total                                     2:00:00

Timesheet: sheet2
    Day                Start      End        Duration Notes
    Wed Jun 30, 2021   05:00:00 - 06:00:00    1:00:00
                                              1:00:00
-----------------------------------------------------------
    Total                                     1:00:00
-----------------------------------------------------------
    Grand total                               3:00:00
"));
    }

    #[test]
    fn entries_are_grouped_despite_database_full() {
        let args = Args {
            sheet: Some(Sheet::Full),
            ..Default::default()
        };
        let mut db = SqliteDatabase::from_memory().unwrap();
        let mut out = Vec::new();
        let mut err = Vec::new();
        let config = Default::default();
        std::env::set_var("TZ", "CST+6");

        db.init().unwrap();

        db.entry_insert(Utc.ymd(2021, 6, 30).and_hms(10, 0, 0), Some(Utc.ymd(2021, 6, 30).and_hms(11, 0, 0)), None, "sheet1".into()).unwrap();
        db.entry_insert(Utc.ymd(2021, 6, 30).and_hms(11, 0, 0), Some(Utc.ymd(2021, 6, 30).and_hms(12, 0, 0)), None, "_sheet2".into()).unwrap();
        db.entry_insert(Utc.ymd(2021, 6, 30).and_hms(12, 0, 0), Some(Utc.ymd(2021, 6, 30).and_hms(13, 0, 0)), None, "sheet1".into()).unwrap();

        DisplayCommand::handle(args, &mut db, &mut out, &mut err, &config, Utc::now()).unwrap();

        assert_eq!(Ps(&String::from_utf8_lossy(&out)), Ps("\
Timesheet: _sheet2
    Day                Start      End        Duration Notes
    Wed Jun 30, 2021   05:00:00 - 06:00:00    1:00:00
                                              1:00:00
-----------------------------------------------------------
    Total                                     1:00:00

Timesheet: sheet1
    Day                Start      End        Duration Notes
    Wed Jun 30, 2021   04:00:00 - 05:00:00    1:00:00
                       06:00:00 - 07:00:00    1:00:00
                                              2:00:00
-----------------------------------------------------------
    Total                                     2:00:00
-----------------------------------------------------------
    Grand total                               3:00:00
"));
    }

    #[test]
    fn filter_old_database() {
        std::env::set_var("TZ", "CST+6");

        let args = Args {
            format: Formatter::Csv,
            start: Some(Utc.ymd(2021, 6, 29).and_hms(12, 0, 0)),
            end: Some(Utc.ymd(2021, 6, 29).and_hms(13, 0, 0)),
            ..Default::default()
        };
        let mut db = SqliteDatabase::from_path("assets/test_old_db.db").unwrap();
        let mut out = Vec::new();
        let mut err = Vec::new();
        let config = Default::default();

        // item in database:
        //     start: 2021-06-29 06:26:49.580565
        //     end:   2021-06-29 07:26:52.816747

        DisplayCommand::handle(args, &mut db, &mut out, &mut err, &config, Utc::now()).unwrap();

        assert_eq!(Ps(&String::from_utf8_lossy(&out)), Ps("start,end,note,sheet
2021-06-29T12:26:49.580565Z,2021-06-29T13:26:52.816747Z,lets do some rust,default
"));

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