ls.rs

use crate::{color::ColorCtx, util};
use nu_ansi_term::Color;
use tame_gcs::{
    common::StandardQueryParameters,
    objects::{ListOptional, ListResponse, Metadata},
};

#[derive(clap::Parser, Debug)]
pub struct Args {
    /// Recurse into directories, may want to take care with this
    /// as it could consume a lot of memory depending on the contents
    /// you query
    #[structopt(short = 'R', long)]
    recurse: bool,
    /// Displays extended metadata as a table
    #[structopt(short, long)]
    long: bool,
    /// The gs:// url list out
    url: url::Url,
}

/// Does an ls of a gs bucket minus the prefix specified by the user, this
/// tries to mimic [exa](https://github.com/ogham/exa) when it can. Would also
/// be good to support <https://github.com/ogham/exa/blob/master/src/info/filetype.rs> at some point
pub async fn cmd(ctx: &util::RequestContext, args: Args) -> anyhow::Result<()> {
    let oid = util::gs_url_to_object_id(&args.url)?;

    let delimiter = if args.recurse { None } else { Some("/") };
    let mut prefix = oid.object().map_or("", |on| on.as_ref()).to_owned();
    if !prefix.is_empty() && !prefix.ends_with('/') {
        prefix.push('/');
    }

    let prefix_len = prefix.len();
    let prefix = Some(prefix);

    let display = if args.long {
        Display::Long
    } else {
        Display::Normal
    };

    let cc = ColorCtx::from_env();

    let mut recurse = if args.recurse {
        Some(RecursePrinter {
            cc,
            display,
            prefix_len,
            items: Vec::new(),
            current_year: time::OffsetDateTime::now_utc().year(),
        })
    } else {
        None
    };

    let normal = if !args.recurse {
        Some(NormalPrinter {
            cc,
            display,
            prefix_len,
        })
    } else {
        None
    };

    let fields = match display {
        Display::Normal => "items(name), prefixes, nextPageToken",
        Display::Long => "items(name, updated, size), prefixes, nextPageToken",
    };

    let mut page_token: Option<String> = None;
    loop {
        let ls_req = ctx.obj.list(
            oid.bucket(),
            Some(ListOptional {
                delimiter,
                page_token: page_token.as_ref().map(|pt| pt.as_ref()),
                prefix: prefix.as_ref().map(|s| s.as_ref()),
                standard_params: StandardQueryParameters {
                    fields: Some(fields),
                    ..Default::default()
                },
                ..Default::default()
            }),
        )?;

        let ls_res: ListResponse = util::execute(ctx, ls_req).await?;

        if let Some(ref np) = normal {
            np.print(ls_res.objects, ls_res.prefixes);
        } else if let Some(ref mut rec) = recurse {
            rec.append(ls_res.objects);
        }

        // If we have a page token it means there may be more items
        // that fulfill the parameters
        page_token = ls_res.page_token;
        if page_token.is_none() {
            break;
        }
    }

    if let Some(ref rec) = recurse {
        rec.print();
    }

    Ok(())
}

#[derive(Copy, Clone)]
enum Display {
    Normal,
    Long,
}

struct NormalPrinter {
    cc: ColorCtx,
    display: Display,
    prefix_len: usize,
}

fn print_dir(cc: &ColorCtx, display: Display, dir: &str) {
    match display {
        Display::Normal => println!("{}", cc.paint(Color::Blue.bold(), dir)),
        Display::Long => println!(
            "    {} {} {} {}",
            cc.paint(Color::White.dimmed(), "-"),
            cc.paint(Color::White.dimmed(), "  -"),
            cc.paint(Color::White.dimmed(), "-- --- --:--"),
            cc.paint(Color::Blue.bold(), dir),
        ),
    }
}

impl NormalPrinter {
    fn print(&self, items: Vec<Metadata>, prefixes: Vec<String>) {
        let cc = &self.cc;

        let indices = {
            // Determine at which indices we should place the "directories"
            let mut indices = Vec::with_capacity(prefixes.len());

            // So yah...just assume these are always in sorted order...
            for prefix in &prefixes {
                if let Err(i) = items.binary_search_by(|om| om.name.as_ref().unwrap().cmp(prefix)) {
                    indices.push(i);
                }
            }

            indices
        };

        let mut next_dir_iter = indices.iter().enumerate();
        let mut next_dir = next_dir_iter.next();

        let current_year = time::OffsetDateTime::now_utc().year();

        for (i, item) in items.into_iter().enumerate() {
            if let Some(dir) = next_dir {
                if *dir.1 == i {
                    let dir = &(&prefixes[dir.0])[self.prefix_len..];
                    let dir = &dir[..dir.len() - 1]; // Remove trailing delimiter

                    print_dir(&self.cc, self.display, dir);

                    next_dir = next_dir_iter.next();
                }
            }

            let filename = &item.name.unwrap()[self.prefix_len..];

            match self.display {
                Display::Normal => println!("{}", cc.paint(Color::White, filename)),
                Display::Long => {
                    use number_prefix::NumberPrefix;

                    let size_str = match NumberPrefix::decimal(item.size.unwrap_or_default() as f64)
                    {
                        NumberPrefix::Standalone(b) => b.to_string(),
                        NumberPrefix::Prefixed(p, n) => {
                            if n < 10f64 {
                                format!("{:.1}{}", n, p.symbol())
                            } else {
                                format!("{:.0}{}", n, p.symbol())
                            }
                        }
                    };

                    let updated = item.updated.unwrap();

                    let updated_str = timestamp_str(updated, current_year);

                    println!(
                        " {}{} {} {} {}",
                        if size_str.len() < 4 { " " } else { "" },
                        cc.paint(Color::Green, size_str),
                        cc.paint(Color::Yellow, "gcs"),
                        cc.paint(Color::Blue, updated_str),
                        cc.paint(Color::White, filename),
                    );
                }
            }
        }

        while let Some(dir) = next_dir {
            let dir = &(&prefixes[dir.0])[self.prefix_len..];
            let dir = &dir[..dir.len() - 1]; // Remove trailing delimiter

            print_dir(&self.cc, self.display, dir);

            next_dir = next_dir_iter.next();
        }
    }
}

fn timestamp_str(ts: time::OffsetDateTime, current_year: i32) -> String {
    const RECENT: &[time::format_description::FormatItem<'_>] =
        time::macros::format_description!("[day] [month repr:short] [hour]:[minute]");
    const OLD: &[time::format_description::FormatItem<'_>] =
        time::macros::format_description!("[day] [month repr:short]  [year]");

    if ts.year() == current_year {
        ts.format(&RECENT)
    } else {
        ts.format(&OLD)
    }
    .unwrap()
}

struct SimpleMetadata {
    name: String,
    size: u64,
    updated: String,
}

struct RecursePrinter {
    cc: ColorCtx,
    display: Display,
    prefix_len: usize,
    items: Vec<Vec<SimpleMetadata>>,
    current_year: i32,
}

use std::io::Write;

impl RecursePrinter {
    fn append(&mut self, items: Vec<Metadata>) {
        let items = items
            .into_iter()
            .map(|md| SimpleMetadata {
                name: String::from(&md.name.unwrap()[self.prefix_len..]),
                size: md.size.unwrap_or_default(),
                updated: md
                    .updated
                    .map(|dt| timestamp_str(dt, self.current_year))
                    .unwrap_or_default(),
            })
            .collect();

        self.items.push(items);
    }

    fn print(&self) {
        let mut stdout = std::io::stdout().lock();

        let mut dirs = vec![String::new()];

        while let Some(dir) = dirs.pop() {
            if !dir.is_empty() {
                writeln!(stdout, "\n{}:", &dir[..dir.len() - 1]).unwrap();
            }

            dirs.extend(self.print_dir(dir, &mut stdout));
        }
    }

    fn print_dir(&self, dir: String, out: &mut std::io::StdoutLock<'static>) -> Vec<String> {
        let cc = &self.cc;
        let mut new_dirs = Vec::new();

        for set in &self.items {
            for item in set {
                if item.name.starts_with(&dir) {
                    let scoped_name = &item.name[dir.len()..];

                    match scoped_name.find('/') {
                        Some(sep) => {
                            let dir_name = &scoped_name[..=sep];
                            if new_dirs
                                .iter()
                                .any(|d: &String| &d[dir.len()..] == dir_name)
                            {
                                continue;
                            }

                            match self.display {
                                Display::Normal => writeln!(
                                    out,
                                    "{}",
                                    cc.paint(Color::Blue.bold(), &dir_name[..dir_name.len() - 1])
                                )
                                .unwrap(),
                                Display::Long => writeln!(
                                    out,
                                    "    {} {} {} {}",
                                    cc.paint(Color::White.dimmed(), "-"),
                                    cc.paint(Color::White.dimmed(), "  -"),
                                    cc.paint(Color::White.dimmed(), "-- --- --:--"),
                                    cc.paint(Color::Blue.bold(), &dir_name[..dir_name.len() - 1]),
                                )
                                .unwrap(),
                            }

                            new_dirs.push(format!("{}{}", dir, dir_name));
                        }
                        None => match self.display {
                            Display::Normal => {
                                writeln!(out, "{}", cc.paint(Color::White, scoped_name)).unwrap();
                            }
                            Display::Long => {
                                use number_prefix::NumberPrefix;

                                let size_str = match NumberPrefix::decimal(item.size as f64) {
                                    NumberPrefix::Standalone(b) => b.to_string(),
                                    NumberPrefix::Prefixed(p, n) => {
                                        if n < 10f64 {
                                            format!("{:.1}{}", n, p.symbol())
                                        } else {
                                            format!("{:.0}{}", n, p.symbol())
                                        }
                                    }
                                };

                                writeln!(
                                    out,
                                    " {}{} {} {} {}",
                                    if size_str.len() < 4 { " " } else { "" },
                                    cc.paint(Color::Green, size_str),
                                    cc.paint(Color::Yellow, "gcs"),
                                    cc.paint(Color::Blue, &item.updated),
                                    cc.paint(Color::White, scoped_name),
                                )
                                .unwrap();
                            }
                        },
                    }
                }
            }
        }

        // The directories act as a queue, so reverse them so they are sorted correctly
        new_dirs.reverse();
        new_dirs
    }
}