use std::convert::TryFrom;
use std::io::{BufRead, 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::timeparse::parse_time;
use crate::regex::parse_regex;
use crate::old::{entries_or_warning, time_or_warning, warn_if_needed};
use crate::io::Streams;

use super::{Command, Facts};

// ----------------------------------------------------------------
// 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, I, O, E>(
    start: Option<DateTime<Utc>>, end: Option<DateTime<Utc>>,
    sheet: Option<Sheet>, streams: &mut Streams<D, I, O, E>,
    format: Formatter, ids: bool, grep: Option<Regex>,
    facts: &Facts,
) -> Result<()>
where
    D: Database,
    I: BufRead,
    O: Write,
    E: Write,
{
    let start = start.map(|s| time_or_warning(s, &streams.db)).transpose()?.map(|s| s.0);
    let end = end.map(|e| time_or_warning(e, &streams.db)).transpose()?.map(|e| e.0);

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

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

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

    let (entries, needs_warning) = entries_or_warning(entries, &streams.db)?;

    format.print_formatted(
        entries,
        &mut streams.out,
        &mut streams.err,
        facts,
        ids,
    )?;

    warn_if_needed(&mut streams.err, needs_warning, &facts.env)?;

    Ok(())
}

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

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

impl<'a> TryFrom<&'a ArgMatches> 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(parse_time).transpose()?,
            end: matches.value_of("end").map(parse_time).transpose()?,
            format: matches.value_of("format").map(|v| v.parse()).transpose()?,
            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, I, O, E>(args: Self::Args, streams: &mut Streams<D, I, O, E>, facts: &Facts) -> Result<()>
    where
        D: Database,
        I: BufRead,
        O: Write,
        E: Write,
    {
        entries_for_display(
            args.start,
            args.end,
            args.sheet,
            streams,
            args.format.unwrap_or_else(|| facts.config.commands.display.default_formatter.as_ref().unwrap_or(&facts.config.default_formatter).clone()),
            args.ids,
            args.grep,
            facts
        )
    }
}

#[cfg(test)]
mod tests {
    use chrono::TimeZone;
    use pretty_assertions::{assert_eq, assert_str_eq};

    use crate::database::SqliteDatabase;
    use crate::config::{Config, CommandsSettings, BaseCommandSettings};

    use super::*;

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

        let args = Default::default();
        let mut streams = Streams::fake(b"").with_db(
            SqliteDatabase::from_path("assets/test_old_db.db").unwrap()
        );
        let facts = Facts::new();

        DisplayCommand::handle(args, &mut streams, &facts).unwrap();

        assert_eq!(&String::from_utf8_lossy(&streams.out), "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(&streams.err),
            "[WARNING] You are using the old timetrap format, it is advised that you update your database using t migrate. To supress this warning set TIEMPO_SUPRESS_TIMETRAP_WARNING=1\n"
        );
    }

    #[test]
    fn filter_by_start() {
        let args = Args {
            format: Some(Formatter::Csv),
            start: Some(Utc.with_ymd_and_hms(2021, 6, 30, 10, 5, 0).unwrap()),
            ..Default::default()
        };
        let mut streams = Streams::fake(b"");
        let facts = Facts::new();

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

        DisplayCommand::handle(args, &mut streams, &facts).unwrap();

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

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

    #[test]
    fn filter_by_match() {
        let mut streams = Streams::fake(b"");
        let facts = Facts::new();

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

        entries_for_display(None, None, None, &mut streams, Formatter::Csv, true, Some("io".parse().unwrap()), &facts).unwrap();

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

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

    #[test]
    fn entries_are_grouped_despite_database() {
        let args = Args {
            sheet: Some(Sheet::All),
            ..Default::default()
        };
        let mut streams = Streams::fake(b"");
        let facts = Facts::new();
        std::env::set_var("TZ", "CST+6");

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

        DisplayCommand::handle(args, &mut streams, &facts).unwrap();

        assert_str_eq!(&String::from_utf8_lossy(&streams.out), "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 streams = Streams::fake(b"");
        let facts = Facts::new();
        std::env::set_var("TZ", "CST+6");

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

        DisplayCommand::handle(args, &mut streams, &facts).unwrap();

        assert_eq!(&String::from_utf8_lossy(&streams.out), "\
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: Some(Formatter::Csv),
            start: Some(Utc.with_ymd_and_hms(2021, 6, 29, 12, 0, 0).unwrap()),
            end: Some(Utc.with_ymd_and_hms(2021, 6, 29, 13, 0, 0).unwrap()),
            ..Default::default()
        };
        let mut streams = Streams::fake(b"").with_db(
            SqliteDatabase::from_path("assets/test_old_db.db").unwrap()
        );
        let facts = Facts::new();

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

        DisplayCommand::handle(args, &mut streams, &facts).unwrap();

        assert_eq!(&String::from_utf8_lossy(&streams.out), "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(&streams.err),
            "[WARNING] You are using the old timetrap format, it is advised that you update your database using t migrate. To supress this warning set TIEMPO_SUPRESS_TIMETRAP_WARNING=1\n"
        );
    }

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

        let args = Default::default();
        let mut streams = Streams::fake(b"");
        let facts = Facts::new().with_config(Config {
            default_formatter: Formatter::Ids,
            ..Default::default()
        });

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

        DisplayCommand::handle(args, &mut streams, &facts).unwrap();

        assert_eq!(&String::from_utf8_lossy(&streams.out), "1 2\n");
        assert_eq!(String::from_utf8_lossy(&streams.err), "");
    }

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

        let args = Default::default();
        let mut streams = Streams::fake(b"");
        let facts = Facts::new().with_config(Config {
            commands: CommandsSettings {
                display: BaseCommandSettings {
                    default_formatter: Some(Formatter::Ids),
                },
                ..Default::default()
            },
            ..Default::default()
        });

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

        DisplayCommand::handle(args, &mut streams, &facts).unwrap();

        assert_eq!(&String::from_utf8_lossy(&streams.out), "1 2\n");
        assert_eq!(String::from_utf8_lossy(&streams.err), "");
    }
}