btrfs-cli 0.13.0

use crate::{
    Format, RunContext, Runnable,
    util::{SizeFormat, fmt_size, open_path, print_json},
};
use anyhow::{Context, Result};
use btrfs_uapi::quota::{
    QgroupInfo, QgroupLimitFlags, QgroupStatusFlags, qgroupid_level,
    qgroupid_subvolid,
};
use clap::Parser;
use cols::Cols;
use serde::Serialize;
use std::{fmt::Write as _, os::unix::io::AsFd, path::PathBuf};

const HEADING_COLUMN_SELECTION: &str = "Column selection";
const HEADING_FILTERING: &str = "Filtering";
const HEADING_SIZE_UNITS: &str = "Size units";

/// List subvolume quota groups
///
/// Shows all quota groups (qgroups) and their space accounting. Each
/// subvolume automatically gets a level-0 qgroup (e.g. 0/256) that
/// tracks its individual usage. Higher-level qgroups (1/0, 2/0, ...)
/// can be created to group subvolumes and apply shared limits across
/// them.
///
/// Columns:
///
/// qgroupid: the quota group identifier in level/id format. Level 0
/// corresponds to individual subvolumes. Higher levels are user-created
/// grouping containers.
///
/// rfer (referenced): total bytes of data referenced by this qgroup.
/// For level-0 qgroups this is the logical size of all extents in the
/// subvolume. Shared extents (e.g. from snapshots or reflinks) are
/// counted in full by each qgroup that references them.
///
/// excl (exclusive): bytes used exclusively by this qgroup, not shared
/// with any other qgroup at the same level. This is the space that
/// would be freed if the subvolume were deleted (assuming no other
/// references).
///
/// max_rfer: the configured limit on referenced bytes. Writes that
/// would exceed this limit fail with EDQUOT. Shows "none" if no limit
/// is set.
///
/// max_excl: the configured limit on exclusive bytes. Shows "none" if
/// no limit is set.
///
/// In --format modern, the qgroup hierarchy is shown as a tree: higher-
/// level qgroups appear as parents with their member qgroups nested
/// below using tree connectors.
#[derive(Parser, Debug)]
#[allow(clippy::struct_excessive_bools, clippy::doc_markdown)]
pub struct QgroupShowCommand {
    /// Path to a mounted btrfs filesystem
    pub path: PathBuf,

    /// Print parent qgroup id
    #[clap(short = 'p', long, help_heading = HEADING_COLUMN_SELECTION)]
    pub print_parent: bool,

    /// Print child qgroup id
    #[clap(short = 'c', long, help_heading = HEADING_COLUMN_SELECTION)]
    pub print_child: bool,

    /// Print limit of referenced size
    #[clap(short = 'r', long, help_heading = HEADING_COLUMN_SELECTION)]
    pub print_rfer_limit: bool,

    /// Print limit of exclusive size
    #[clap(short = 'e', long, help_heading = HEADING_COLUMN_SELECTION)]
    pub print_excl_limit: bool,

    /// List all qgroups impacting path, including ancestral qgroups
    #[clap(short = 'F', long, help_heading = HEADING_FILTERING)]
    pub filter_all: bool,

    /// List all qgroups impacting path, excluding ancestral qgroups
    #[clap(short = 'f', long, help_heading = HEADING_FILTERING)]
    pub filter_direct: bool,

    /// Show raw numbers in bytes
    #[clap(long, help_heading = HEADING_SIZE_UNITS)]
    pub raw: bool,

    /// Show human friendly numbers, base 1024 (default)
    #[clap(long, help_heading = HEADING_SIZE_UNITS)]
    pub human_readable: bool,

    /// Use 1024 as a base (IEC units)
    #[clap(long, help_heading = HEADING_SIZE_UNITS)]
    pub iec: bool,

    /// Use 1000 as a base (SI units)
    #[clap(long, help_heading = HEADING_SIZE_UNITS)]
    pub si: bool,

    /// Show sizes in KiB
    #[clap(long, help_heading = HEADING_SIZE_UNITS)]
    pub kbytes: bool,

    /// Show sizes in MiB
    #[clap(long, help_heading = HEADING_SIZE_UNITS)]
    pub mbytes: bool,

    /// Show sizes in GiB
    #[clap(long, help_heading = HEADING_SIZE_UNITS)]
    pub gbytes: bool,

    /// Show sizes in TiB
    #[clap(long, help_heading = HEADING_SIZE_UNITS)]
    pub tbytes: bool,

    /// Sort by a comma-separated list of fields (qgroupid, rfer, excl, max_rfer, max_excl)
    #[clap(long)]
    pub sort: Option<SortKeys>,

    /// Force a sync before getting quota information
    #[clap(long)]
    pub sync: bool,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum SortField {
    Qgroupid,
    Rfer,
    Excl,
    MaxRfer,
    MaxExcl,
}

#[derive(Debug, Clone, Copy)]
struct SortKey {
    field: SortField,
    descending: bool,
}

impl std::str::FromStr for SortKey {
    type Err = String;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        let (descending, name) = match s.strip_prefix('-') {
            Some(rest) => (true, rest),
            None => (false, s),
        };
        let field = match name {
            "qgroupid" => SortField::Qgroupid,
            "rfer" => SortField::Rfer,
            "excl" => SortField::Excl,
            "max_rfer" => SortField::MaxRfer,
            "max_excl" => SortField::MaxExcl,
            _ => {
                return Err(format!(
                    "unknown sort field '{name}'; expected qgroupid, rfer, excl, max_rfer, or max_excl"
                ));
            }
        };
        Ok(SortKey { field, descending })
    }
}

/// Comma-separated list of sort keys (e.g. "rfer,-excl").
#[derive(Debug, Clone)]
pub struct SortKeys(Vec<SortKey>);

impl std::str::FromStr for SortKeys {
    type Err = String;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        let keys: Vec<SortKey> = s
            .split(',')
            .map(|part| part.trim().parse())
            .collect::<Result<_, _>>()?;
        if keys.is_empty() {
            return Err("sort field list must not be empty".to_string());
        }
        Ok(SortKeys(keys))
    }
}

fn fmt_limit(
    bytes: u64,
    flags: QgroupLimitFlags,
    flag_bit: QgroupLimitFlags,
    mode: &SizeFormat,
) -> String {
    if bytes == u64::MAX || !flags.contains(flag_bit) {
        "none".to_string()
    } else {
        fmt_size(bytes, mode)
    }
}

fn format_qgroupid(qgroupid: u64) -> String {
    format!(
        "{}/{}",
        qgroupid_level(qgroupid),
        qgroupid_subvolid(qgroupid)
    )
}

#[derive(Serialize)]
struct QgroupJson {
    qgroupid: String,
    rfer: u64,
    excl: u64,
    max_rfer: Option<u64>,
    max_excl: Option<u64>,
    #[serde(skip_serializing_if = "Vec::is_empty")]
    parents: Vec<String>,
    #[serde(skip_serializing_if = "Vec::is_empty")]
    children: Vec<String>,
}

impl QgroupJson {
    fn from_info(q: &QgroupInfo) -> Self {
        let max_rfer = if q.limit_flags.contains(QgroupLimitFlags::MAX_RFER)
            && q.max_rfer != u64::MAX
        {
            Some(q.max_rfer)
        } else {
            None
        };
        let max_excl = if q.limit_flags.contains(QgroupLimitFlags::MAX_EXCL)
            && q.max_excl != u64::MAX
        {
            Some(q.max_excl)
        } else {
            None
        };
        Self {
            qgroupid: format_qgroupid(q.qgroupid),
            rfer: q.rfer,
            excl: q.excl,
            max_rfer,
            max_excl,
            parents: q.parents.iter().map(|&id| format_qgroupid(id)).collect(),
            children: q
                .children
                .iter()
                .map(|&id| format_qgroupid(id))
                .collect(),
        }
    }
}

impl Runnable for QgroupShowCommand {
    fn supported_formats(&self) -> &[Format] {
        &[Format::Text, Format::Json, Format::Modern]
    }

    #[allow(clippy::too_many_lines)]
    fn run(&self, ctx: &RunContext) -> Result<()> {
        // filter_all / filter_direct: not implemented, ignored
        let _ = self.filter_all;
        let _ = self.filter_direct;

        let file = open_path(&self.path)?;
        let fd = file.as_fd();

        if self.sync {
            btrfs_uapi::filesystem::sync(fd).with_context(|| {
                format!("failed to sync '{}'", self.path.display())
            })?;
        }

        let list = btrfs_uapi::quota::qgroup_list(fd).with_context(|| {
            format!("failed to list qgroups on '{}'", self.path.display())
        })?;

        if list.qgroups.is_empty() {
            return Ok(());
        }

        if list.status_flags.contains(QgroupStatusFlags::INCONSISTENT) {
            eprintln!(
                "WARNING: qgroup data is inconsistent, use 'btrfs quota rescan' to fix"
            );
        }

        // Determine display mode
        let si = self.si;
        let mode = if self.raw {
            SizeFormat::Raw
        } else if self.kbytes {
            SizeFormat::Fixed(if si { 1000 } else { 1024 })
        } else if self.mbytes {
            SizeFormat::Fixed(if si { 1_000_000 } else { 1024 * 1024 })
        } else if self.gbytes {
            SizeFormat::Fixed(if si {
                1_000_000_000
            } else {
                1024 * 1024 * 1024
            })
        } else if self.tbytes {
            SizeFormat::Fixed(if si {
                1_000_000_000_000
            } else {
                1024u64.pow(4)
            })
        } else if si {
            SizeFormat::HumanSi
        } else {
            SizeFormat::HumanIec
        };

        // Sort
        let mut qgroups: Vec<QgroupInfo> = list.qgroups.clone();

        match &self.sort {
            Some(SortKeys(keys)) => {
                qgroups.sort_by(|a, b| {
                    for key in keys {
                        let ord = match key.field {
                            SortField::Qgroupid => a.qgroupid.cmp(&b.qgroupid),
                            SortField::Rfer => a.rfer.cmp(&b.rfer),
                            SortField::Excl => a.excl.cmp(&b.excl),
                            SortField::MaxRfer => a.max_rfer.cmp(&b.max_rfer),
                            SortField::MaxExcl => a.max_excl.cmp(&b.max_excl),
                        };
                        let ord =
                            if key.descending { ord.reverse() } else { ord };
                        if ord != std::cmp::Ordering::Equal {
                            return ord;
                        }
                    }
                    std::cmp::Ordering::Equal
                });
            }
            None => {
                qgroups.sort_by_key(|q| q.qgroupid);
            }
        }

        match ctx.format {
            Format::Modern => {
                print_qgroups_modern(self, &qgroups, &mode);
            }
            Format::Text => {
                print_qgroups_text(self, &qgroups, &mode);
            }
            Format::Json => {
                let json: Vec<QgroupJson> =
                    qgroups.iter().map(QgroupJson::from_info).collect();
                print_json("qgroup-show", &json)?;
            }
        }

        Ok(())
    }
}

#[derive(Cols)]
struct QgroupRow {
    #[column(tree)]
    qgroupid: String,
    #[column(header = "RFER", right)]
    rfer: String,
    #[column(header = "EXCL", right)]
    excl: String,
    #[column(header = "MAX_RFER", right)]
    max_rfer: String,
    #[column(header = "MAX_EXCL", right)]
    max_excl: String,
    #[column(children)]
    children: Vec<Self>,
}

impl QgroupRow {
    fn from_info(q: &QgroupInfo, mode: &SizeFormat) -> Self {
        Self {
            qgroupid: format_qgroupid(q.qgroupid),
            rfer: fmt_size(q.rfer, mode),
            excl: fmt_size(q.excl, mode),
            max_rfer: fmt_limit(
                q.max_rfer,
                q.limit_flags,
                QgroupLimitFlags::MAX_RFER,
                mode,
            ),
            max_excl: fmt_limit(
                q.max_excl,
                q.limit_flags,
                QgroupLimitFlags::MAX_EXCL,
                mode,
            ),
            children: Vec::new(),
        }
    }
}

/// Recursively remove a row from the map and attach its children.
fn attach_qgroup_children(
    id: u64,
    rows: &mut std::collections::BTreeMap<u64, QgroupRow>,
    qgroups: &[QgroupInfo],
) -> Option<QgroupRow> {
    let mut row = rows.remove(&id)?;
    if let Some(q) = qgroups.iter().find(|q| q.qgroupid == id) {
        for &child_id in &q.children {
            if let Some(child) = attach_qgroup_children(child_id, rows, qgroups)
            {
                row.children.push(child);
            }
        }
    }
    Some(row)
}

fn print_qgroups_modern(
    _cmd: &QgroupShowCommand,
    qgroups: &[QgroupInfo],
    mode: &SizeFormat,
) {
    use std::collections::BTreeMap;

    let mut rows: BTreeMap<u64, QgroupRow> = qgroups
        .iter()
        .map(|q| (q.qgroupid, QgroupRow::from_info(q, mode)))
        .collect();

    // A qgroup is a root if no other qgroup lists it as a child.
    let mut is_child = std::collections::HashSet::new();
    for q in qgroups {
        for &child_id in &q.children {
            is_child.insert(child_id);
        }
    }

    let root_ids: Vec<u64> = qgroups
        .iter()
        .filter(|q| !is_child.contains(&q.qgroupid))
        .map(|q| q.qgroupid)
        .collect();

    let mut tree: Vec<QgroupRow> = root_ids
        .iter()
        .filter_map(|&id| attach_qgroup_children(id, &mut rows, qgroups))
        .collect();

    // Any orphans (not reachable from roots) go at the top level.
    for (_, row) in rows {
        tree.push(row);
    }

    let mut out = std::io::stdout().lock();
    let _ = QgroupRow::print_table(&tree, &mut out);
}

fn print_qgroups_text(
    cmd: &QgroupShowCommand,
    qgroups: &[QgroupInfo],
    mode: &SizeFormat,
) {
    let mut header =
        format!("{:<16} {:>12} {:>12}", "qgroupid", "rfer", "excl");
    if cmd.print_rfer_limit {
        let _ = write!(header, " {:>12}", "max_rfer");
    }
    if cmd.print_excl_limit {
        let _ = write!(header, " {:>12}", "max_excl");
    }
    if cmd.print_parent {
        let _ = write!(header, "  {:<20}", "parent");
    }
    if cmd.print_child {
        let _ = write!(header, "  {:<20}", "child");
    }
    println!("{header}");

    for q in qgroups {
        let id_str = format_qgroupid(q.qgroupid);
        let rfer_str = fmt_size(q.rfer, mode);
        let excl_str = fmt_size(q.excl, mode);

        let mut line = format!("{id_str:<16} {rfer_str:>12} {excl_str:>12}");

        if cmd.print_rfer_limit {
            let s = fmt_limit(
                q.max_rfer,
                q.limit_flags,
                QgroupLimitFlags::MAX_RFER,
                mode,
            );
            let _ = write!(line, " {s:>12}");
        }

        if cmd.print_excl_limit {
            let s = fmt_limit(
                q.max_excl,
                q.limit_flags,
                QgroupLimitFlags::MAX_EXCL,
                mode,
            );
            let _ = write!(line, " {s:>12}");
        }

        if cmd.print_parent {
            let parents: Vec<String> =
                q.parents.iter().map(|&id| format_qgroupid(id)).collect();
            let _ = write!(line, "  {:<20}", parents.join(","));
        }

        if cmd.print_child {
            let children: Vec<String> =
                q.children.iter().map(|&id| format_qgroupid(id)).collect();
            let _ = write!(line, "  {:<20}", children.join(","));
        }

        println!("{line}");
    }
}