//! Commands that act on the local repository and working copy.

use super::format::{author_name, deps_line, deps_of, plural, short_id, short_meta_id, signature_line, signature_mark, subject_of, when};
use super::json;
use oxy_core::repo::SignatureStatus;
use super::open;
use super::ui;
use anyhow::Result;
use oxy_core::objects::ChangeKind;
use oxy_core::repo::{render_change, ChangeStatus, Repo};
use std::path::PathBuf;

pub fn init(path: Option<PathBuf>) -> Result<i32> {
    let path = path.unwrap_or(std::env::current_dir()?);
    let repo = Repo::init(&path)?;
    println!("{} oxy repository in {}", ui::done("Initialized"), ui::path(repo.root().display()));
    println!("{}", ui::kv("bookmark", ui::bookmark(&repo.config.bookmark)));
    println!("{}", ui::kv("author", format!("{} <{}>", ui::author(&repo.config.author_name), repo.config.author_email)));
    Ok(0)
}

fn status_tag(s: ChangeStatus) -> &'static str {
    match s {
        ChangeStatus::Added => "A",
        ChangeStatus::Modified => "M",
        ChangeStatus::Removed => "D",
        ChangeStatus::Renamed => "R",
        ChangeStatus::ModeChanged => "X",
        ChangeStatus::ConflictEdited => "C!",
        ChangeStatus::Resolved => "V",
    }
}

pub fn status(json: bool) -> Result<i32> {
    let repo = open()?;
    let sp = ui::spinner("Snapshotting the working copy…");
    let snap = repo.snapshot("oxy status")?;
    let heads = repo.bookmark_heads()?;
    sp.clear();
    if json {
        println!("{}", repo.status_json(&snap)?);
        return Ok(if snap.base_snapshot.is_conflicted() { 2 } else { 0 });
    }
    println!(
        "{} {}{}working copy {}{}{}",
        ui::dim("On"),
        ui::bookmark(&repo.config.bookmark),
        ui::sep(),
        ui::id(snap.wc.change_id.short(8)),
        ui::sep(),
        ui::dim(plural(heads.len(), "head"))
    );
    if snap.statuses.is_empty() {
        println!("  {} {}", ui::ok(ui::glyph("✔", "*")), ui::dim("nothing to commit, working copy clean"));
    } else {
        println!();
        for s in &snap.statuses {
            println!("  {} {}", ui::status_mark(status_tag(s.status)), ui::path(&s.path));
        }
    }
    if !snap.base_snapshot.is_conflicted() {
        return Ok(0);
    }
    println!();
    println!("{} {}", ui::section(ui::err("Conflicts")), ui::dim("edit the marked files, or the .oxy-conflict-N candidates, then commit"));
    for c in &snap.base_snapshot.tree.conflicts {
        println!("  {} tree: {c:?}", ui::err(ui::glyph("✱", "!")));
    }
    for (p, f) in &snap.base_snapshot.files {
        if f.is_conflicted() {
            let state = match snap.statuses.iter().find(|s| s.path == *p).map(|s| s.status) {
                Some(ChangeStatus::Resolved) => ui::ok(format!("{} resolved in working copy", ui::glyph("✔", "*"))),
                Some(ChangeStatus::ConflictEdited) => ui::warn(format!("{} markers remain", ui::glyph("‼", "!"))),
                _ => ui::err(format!("{} unresolved", ui::glyph("✱", "!"))),
            };
            println!("  {}  {state}", ui::path(p));
        }
    }
    Ok(2)
}

pub fn commit(message: &str, depends_on: &[String], paths: &[String], interactive: bool, hunks: &[usize]) -> Result<i32> {
    let repo = open()?;
    let mut deps = Vec::new();
    for d in depends_on {
        deps.push(repo.resolve_change(d)?);
    }
    let selection = if !hunks.is_empty() {
        oxy_core::repo::Selection::Hunks(hunks.to_vec())
    } else if interactive {
        let (_, hunks) = repo.hunks()?;
        if hunks.is_empty() {
            anyhow::bail!("nothing to commit: the working copy matches its base");
        }
        let hunks: Vec<_> = hunks.into_iter().filter(|h| paths.is_empty() || paths.iter().any(|p| h.path == *p || h.path.starts_with(&format!("{}/", p.trim_end_matches('/'))))).collect();
        let mut chosen = Vec::new();
        let stdin = std::io::stdin();
        let mut take_rest = false;
        for (n, h) in hunks.iter().enumerate() {
            if take_rest {
                chosen.push(h.index);
                continue;
            }
            println!("{} {} {}", ui::section(format!("hunk {} of {}", n + 1, hunks.len())), ui::path(&h.path), ui::dim(format!("(#{})", h.index)));
            for line in h.text.lines() {
                let styled = if line.starts_with('+') { ui::ok(line) } else if line.starts_with('-') { ui::err(line) } else { ui::dim(line) };
                println!("  {styled}");
            }
            loop {
                print!("{} ", ui::warn("Commit this hunk? [y]es [n]o [a]ll remaining [q]uit:"));
                use std::io::Write as _;
                std::io::stdout().flush()?;
                let mut answer = String::new();
                if stdin.read_line(&mut answer)? == 0 {
                    anyhow::bail!("aborted");
                }
                match answer.trim() {
                    "y" | "Y" => {
                        chosen.push(h.index);
                        break;
                    }
                    "n" | "N" | "" => break,
                    "a" | "A" => {
                        chosen.push(h.index);
                        take_rest = true;
                        break;
                    }
                    "q" | "Q" => anyhow::bail!("aborted; nothing committed"),
                    _ => continue,
                }
            }
        }
        if chosen.is_empty() {
            anyhow::bail!("no hunks chosen; nothing committed");
        }
        oxy_core::repo::Selection::Hunks(chosen)
    } else if paths.is_empty() {
        oxy_core::repo::Selection::All
    } else {
        oxy_core::repo::Selection::Paths(paths.to_vec())
    };
    let sp = ui::spinner("Committing…");
    let h = repo.commit_selection(message, &deps, &selection)?;
    let c = repo.store().get_change(&h)?;
    sp.done(&format!("{} {} {}  {}", ui::done("Committed"), ui::id(short_id(&c)), ui::hash(format!("#{}", h.short(12))), ui::subject(subject_of(message))));
    if !matches!(selection, oxy_core::repo::Selection::All) {
        let rest = repo.snapshot("oxy commit")?;
        if !rest.statuses.is_empty() {
            println!("  {} {}", ui::note(), ui::dim(format!("{} left uncommitted", plural(rest.statuses.len(), "path"))));
        }
    }
    Ok(0)
}

pub fn blame(path: &str, json: bool) -> Result<i32> {
    let repo = open()?;
    let lines = repo.blame(path)?;
    if json {
        let items = lines.iter().map(|l| {
            format!(
                "{{\"line\":{},\"change_id\":{},\"hash\":{},\"index\":{},\"author\":{},\"when_ms\":{}}}",
                l.line,
                oxy_core::repo::json_str(&l.change_id.to_hex()),
                oxy_core::repo::json_str(&l.hash.to_hex()),
                l.index,
                oxy_core::repo::json_str(&l.author),
                l.when_ms
            )
        });
        println!("{}", oxy_core::repo::json_array(items));
        return Ok(0);
    }
    let width = lines.iter().map(|l| l.author.chars().count()).max().unwrap_or(0).min(20);
    let digits = lines.len().to_string().len();
    for l in &lines {
        let author: String = l.author.chars().take(20).collect();
        let text = String::from_utf8_lossy(&l.text);
        println!(
            "{} {} {} {:>digits$}{} {}",
            ui::id(l.change_id.short(8)),
            ui::author(format!("{author:<width$}")),
            ui::dim(ui::ago(l.when_ms)),
            l.line,
            ui::dim(ui::glyph("│", "|")),
            text.trim_end_matches('\n')
        );
    }
    Ok(0)
}

fn bisect_report(repo: &Repo, step: &oxy_core::repo::BisectStep) -> Result<i32> {
    use oxy_core::repo::BisectStep::*;
    match step {
        NeedMarks { good, bad } => {
            println!("{} {} {}", ui::note(), ui::dim(format!("{good} good, {bad} bad;")), ui::dim(if *good == 0 { "mark a known-good change or bookmark: oxy bisect good CHANGE" } else { "mark a known-bad change or bookmark: oxy bisect bad CHANGE" }));
            Ok(0)
        }
        Testing { heads, remaining, steps_left } => {
            println!("{} {} {}", ui::done("Testing"), ui::dim(format!("{} in the state under test;", plural(heads.len(), "head"))), ui::dim(format!("{remaining} candidates left, about {steps_left} more steps")));
            println!("  {} {}", ui::note(), ui::dim("run your test, then oxy bisect good | bad | skip"));
            Ok(0)
        }
        Found { culprit } => {
            let c = repo.store().get_change(culprit)?;
            println!("{} {} {}  {}", ui::done("Found"), ui::id(short_id(&c)), ui::hash(format!("#{}", culprit.short(12))), ui::subject(subject_of(&c.message)));
            println!("  {} {}", ui::note(), ui::dim("the first change whose inclusion makes the state bad; oxy bisect reset to return"));
            Ok(0)
        }
        Inconclusive { candidates } => {
            println!("{} {}", ui::caution(), ui::warn(format!("every remaining candidate was skipped ({}); oxy bisect reset to return", plural(candidates.len(), "change"))));
            Ok(1)
        }
    }
}

pub fn bisect_start() -> Result<i32> {
    let repo = open()?;
    repo.bisect_start()?;
    println!("{} bisect; {}", ui::done("Started"), ui::dim("now: oxy bisect good CHANGE and oxy bisect bad CHANGE"));
    Ok(0)
}

pub fn bisect_mark(good: Option<bool>, changes: &[String]) -> Result<i32> {
    let repo = open()?;
    let mut heads = Vec::new();
    for c in changes {
        heads.extend(repo.resolve_heads(c)?);
    }
    let step = repo.bisect_mark(good, &heads)?;
    bisect_report(&repo, &step)
}

pub fn bisect_run(command: &[String]) -> Result<i32> {
    let repo = open()?;
    let step = repo.bisect_run(command)?;
    bisect_report(&repo, &step)
}

pub fn bisect_status(as_json: bool) -> Result<i32> {
    let repo = open()?;
    if as_json {
        use oxy_core::repo::BisectStep::*;
        let v = match repo.bisect_status()? {
            None => "null".to_string(),
            Some(NeedMarks { good, bad }) => json::obj([("state", json::s("need-marks")), ("good", json::n(good)), ("bad", json::n(bad))]),
            Some(Testing { heads, remaining, steps_left }) => json::obj([("state", json::s("testing")), ("heads", json::hashes(&heads)), ("remaining", json::n(remaining)), ("steps_left", json::n(steps_left))]),
            Some(Found { culprit }) => json::obj([("state", json::s("found")), ("culprit", json::s(&culprit.to_hex()))]),
            Some(Inconclusive { candidates }) => json::obj([("state", json::s("inconclusive")), ("candidates", json::hashes(&candidates))]),
        };
        println!("{v}");
        return Ok(0);
    }
    match repo.bisect_status()? {
        None => {
            println!("{}", ui::dim("No bisect in progress."));
            Ok(0)
        }
        Some(step) => bisect_report(&repo, &step),
    }
}

pub fn bisect_reset() -> Result<i32> {
    let repo = open()?;
    repo.bisect_reset()?;
    println!("{} bisect; working copy restored", ui::done("Reset"));
    Ok(0)
}

/// The log: one entry per change, newest first, joined by a rail. The
/// default view is the subject and a metadata line; `verbose` adds the full
/// message, dependencies, and the authenticating key.
fn signature_json(repo: &Repo, h: &oxy_core::hash::ChangeHash) -> Result<String> {
    Ok(match repo.authenticate_change(h)? {
        SignatureStatus::Unsigned => json::obj([("status", json::s("unsigned"))]),
        SignatureStatus::Valid { key, name, email, sealed, revoked } => json::obj([
            ("status", json::s(if sealed { "sealed" } else { "signed" })),
            ("key", json::s(&key.to_hex())),
            ("name", json::s(&name)),
            ("email", json::s(&email)),
            ("revoked", json::b(revoked)),
        ]),
        SignatureStatus::Invalid(why) => json::obj([("status", json::s("invalid")), ("reason", json::s(&why))]),
    })
}

fn log_entry_json(repo: &Repo, e: &oxy_core::repo::LogEntry) -> Result<String> {
    let c = &e.change;
    Ok(json::obj([
        ("hash", json::s(&e.hash.to_hex())),
        ("change_id", json::s(&c.change_id.to_hex())),
        ("author", json::s(&author_name(repo, c))),
        ("author_key", json::s(&c.author.to_hex())),
        ("when_ms", json::n(c.hlc.wall_ms)),
        ("message", json::s(&c.message)),
        ("kind", json::s(&format!("{:?}", c.kind).to_lowercase())),
        ("deps", json::hashes(&c.deps)),
        ("head", json::b(e.is_head)),
        ("working_copy", json::b(e.is_working_copy)),
        ("signature", if e.is_working_copy { "null".into() } else { signature_json(repo, &e.hash)? }),
    ]))
}

pub fn log(limit: Option<usize>, verbose: bool, path: Option<&str>, as_json: bool) -> Result<i32> {
    let repo = open()?;
    let snap = repo.snapshot("oxy log")?;
    let conflicted = snap.base_snapshot.is_conflicted();
    let entries = match path {
        Some(p) => repo.log_for_path(p)?,
        None => repo.log()?,
    };
    if as_json {
        let shown = limit.unwrap_or(entries.len()).min(entries.len());
        let mut items = Vec::new();
        for e in entries.iter().take(shown) {
            items.push(log_entry_json(&repo, e)?);
        }
        println!("{}", json::obj([("bookmark", json::s(&repo.config.bookmark)), ("total", json::n(entries.len())), ("changes", json::arr(items))]));
        return Ok(0);
    }
    let total = entries.len();
    let shown = limit.unwrap_or(total).min(total);
    let rail = ui::rail();
    for (i, e) in entries.iter().take(shown).enumerate() {
        let c = &e.change;
        let bullet = ui::log_bullet(e.is_working_copy, e.is_head, e.is_working_copy && conflicted);
        let mut labels = Vec::new();
        if e.is_working_copy {
            labels.push(ui::warn("working copy"));
        }
        if c.kind == ChangeKind::Resolution {
            labels.push(ui::warn("resolution"));
        }
        let labels = if labels.is_empty() { String::new() } else { format!(" {}{}{}", ui::dim("("), labels.join(ui::dim(", ").as_str()), ui::dim(")")) };
        let subject = if e.is_working_copy && c.message.is_empty() {
            ui::dim(if snap.statuses.is_empty() { "(clean)" } else { "(uncommitted changes)" })
        } else {
            ui::subject(subject_of(&c.message))
        };
        println!("{bullet} {}{labels}  {subject}", ui::id(short_meta_id(c)));
        let meta = format!(
            "{}{}{}{}{}{}{}",
            ui::hash(format!("#{}", e.hash.short(12))),
            ui::sep(),
            ui::author(author_name(&repo, c)),
            ui::sep(),
            ui::dim(ui::ago(c.hlc.wall_ms)),
            ui::sep(),
            if e.is_working_copy { ui::dim("not yet committed") } else { signature_mark(&repo, &e.hash)? }
        );
        println!("{rail} {meta}");
        if verbose {
            if !e.is_working_copy {
                println!("{rail} {}", ui::dim(format!("{} {}", when(c.hlc.wall_ms), signature_line(&repo, &e.hash)?)));
            }
            if !c.deps.is_empty() {
                println!("{rail} {} {}", ui::dim(ui::glyph("↳", "->")), ui::dim(deps_of(&c.deps)));
            }
            let body: Vec<&str> = c.message.lines().skip(1).skip_while(|l| l.trim().is_empty()).collect();
            if !body.is_empty() {
                println!("{rail}");
                for line in body {
                    println!("{rail}   {line}");
                }
            }
        }
        if i + 1 < shown {
            println!("{rail}");
        }
    }
    if shown < total {
        println!("{}", ui::dim(format!("{} {} more; pass -n to see them", ui::glyph("…", "..."), total - shown)));
    }
    Ok(0)
}

pub fn diff(change: Option<&str>, as_json: bool) -> Result<i32> {
    let repo = open()?;
    let hash = change.map(|c| repo.resolve_change(c)).transpose()?;
    if as_json {
        let files = repo.diff_files(hash.as_ref())?;
        let items = files.iter().map(|f| {
            json::obj([
                ("path", json::s(&f.path)),
                ("kind", json::s(&f.kind)),
                ("from", json::opt(f.from.as_deref(), json::s)),
                (
                    "hunks",
                    json::arr(f.hunks.iter().map(|h| {
                        json::obj([
                            ("base_line", json::n(h.base_line)),
                            ("added", json::arr(h.added.iter().map(|l| json::s(&String::from_utf8_lossy(l))))),
                            ("removed", json::arr(h.removed.iter().map(|(n, l)| json::obj([("line", json::n(*n)), ("text", json::s(&String::from_utf8_lossy(l)))])))),
                        ])
                    })),
                ),
            ])
        });
        println!("{}", json::obj([("change", json::opt(hash, |h| json::s(&h.to_hex()))), ("files", json::arr(items))]));
        return Ok(0);
    }
    match hash {
        Some(h) => {
            let c = repo.store().get_change(&h)?;
            let base = repo.load_state(&c.deps)?;
            let snapshot = base.materialize();
            print!("{}", render_change(&c, &base, &snapshot));
        }
        None => {
            let snap = repo.snapshot("oxy diff")?;
            print!("{}", render_change(&snap.wc, &snap.base, &snap.base_snapshot));
        }
    }
    Ok(0)
}

pub fn cat(path: &str, change: Option<&str>) -> Result<i32> {
    let repo = open()?;
    let heads = change.map(|c| repo.resolve_heads(c)).transpose()?;
    let bytes = repo.file_at(path, heads.as_deref())?;
    use std::io::Write as _;
    std::io::stdout().write_all(&bytes)?;
    Ok(0)
}

pub fn root(as_json: bool) -> Result<i32> {
    let Ok(repo) = Repo::open(&std::env::current_dir()?) else {
        if as_json {
            println!("null");
        }
        return Ok(1);
    };
    if as_json {
        println!("{}", json::obj([("root", json::s(&repo.root().to_string_lossy())), ("workspace", json::s(&repo.workspace().to_hex())), ("bookmark", json::s(&repo.config.bookmark))]));
    } else {
        println!("{}", repo.root().display());
    }
    Ok(0)
}

pub fn version(as_json: bool) -> Result<i32> {
    if as_json {
        println!("{}", json::obj([("version", json::s(env!("CARGO_PKG_VERSION"))), ("protocol", json::n(oxy_core::protocol::PROTOCOL_VERSION)), ("format", json::n(2))]));
    } else {
        println!("oxy {} (repository format 2, protocol {})", env!("CARGO_PKG_VERSION"), oxy_core::protocol::PROTOCOL_VERSION);
    }
    Ok(0)
}

pub fn discard(paths: &[String], hunks: &[usize]) -> Result<i32> {
    let repo = open()?;
    if paths.is_empty() && hunks.is_empty() {
        anyhow::bail!("name paths to restore, or --hunks to undo chosen hunks");
    }
    let mut n = 0;
    if !hunks.is_empty() {
        n += repo.discard_hunks(hunks)?;
    }
    if !paths.is_empty() {
        n += repo.discard(paths)?;
    }
    println!("{} {} restored to the working copy's base", ui::done("Discarded"), plural(n, "path"));
    Ok(0)
}

pub fn hunks(as_json: bool) -> Result<i32> {
    let repo = open()?;
    let (_, hunks) = repo.hunks()?;
    if as_json {
        println!("{}", json::arr(hunks.iter().map(|h| json::obj([("index", json::n(h.index)), ("path", json::s(&h.path)), ("text", json::s(&h.text))]))));
        return Ok(0);
    }
    if hunks.is_empty() {
        println!("{}", ui::dim("No hunks: the working copy matches its base."));
    }
    for h in &hunks {
        println!("{} {}", ui::section(format!("hunk {}", h.index)), ui::path(&h.path));
        for line in h.text.lines() {
            let styled = if line.starts_with('+') { ui::ok(line) } else if line.starts_with('-') { ui::err(line) } else { ui::dim(line) };
            println!("  {styled}");
        }
    }
    Ok(0)
}

pub fn show(change: &str, as_json: bool) -> Result<i32> {
    let repo = open()?;
    repo.snapshot("oxy show")?;
    let h = repo.resolve_change(change)?;
    let c = repo.store().get_change(&h)?;
    if as_json {
        let files = repo.diff_files(Some(&h))?;
        let heads = repo.bookmark_heads()?;
        let entry = oxy_core::repo::LogEntry { hash: h, change: oxy_core::state::ChangeMeta::of(&c), is_working_copy: c.kind == oxy_core::objects::ChangeKind::WorkingCopy, is_head: heads.contains(&h) };
        let mut body = log_entry_json(&repo, &entry)?;
        body.pop();
        body.push_str(&format!(",{}:{}}}", json::s("files"), json::arr(files.iter().map(|f| json::obj([("path", json::s(&f.path)), ("kind", json::s(&f.kind)), ("from", json::opt(f.from.as_deref(), json::s))])))));
        println!("{body}");
        return Ok(0);
    }
    println!("{} {} {}", ui::section("change"), ui::id(short_id(&c)), ui::hash(format!("#{h}")));
    println!("{}", ui::kv("kind", format!("{:?}", c.kind).to_lowercase()));
    println!("{}", ui::kv("author", ui::author(author_name(&repo, &oxy_core::state::ChangeMeta::of(&c)))));
    println!("{}", ui::kv("date", format!("{} {}", when(c.hlc.wall_ms), ui::dim(format!("({})", ui::ago(c.hlc.wall_ms))))));
    println!("{}", ui::kv("deps", ui::dim(deps_line(&c))));
    println!("{}", ui::kv("sig", signature_line(&repo, &h)?));
    println!();
    for line in (if c.message.is_empty() { "(no description)" } else { &c.message }).lines() {
        println!("    {line}");
    }
    println!();
    print!("{}", repo.describe_change(&h)?);
    Ok(0)
}

pub fn checkout(changes: &[String], discard: bool) -> Result<i32> {
    let repo = open()?;
    let heads = if changes.is_empty() {
        repo.bookmark_heads()?
    } else {
        let mut heads = Vec::new();
        for c in changes {
            heads.extend(repo.resolve_heads(c)?);
        }
        heads
    };
    let spec = if changes.is_empty() { repo.config.bookmark.clone() } else { changes.join(" ") };
    let sp = ui::spinner(&format!("Checking out {spec}…"));
    let r = repo.checkout(&heads, discard, &format!("oxy checkout {spec}"))?;
    sp.done(&format!("{} on {}: {} written, {} removed", ui::done("Working copy"), ui::bookmark(&spec), plural(r.written, "file"), r.removed));
    for n in &r.notes {
        println!("  {} {n}", ui::note());
    }
    if r.conflicted {
        println!("  {} {}", ui::caution(), ui::warn("this state has conflicts; see oxy status"));
    }
    Ok(0)
}

pub fn resolve(as_json: bool) -> Result<i32> {
    let repo = open()?;
    let snap = repo.snapshot("oxy resolve")?;
    if as_json {
        println!("{}", repo.status_json(&snap)?);
        return Ok(if snap.base_snapshot.is_conflicted() { 2 } else { 0 });
    }
    if !snap.base_snapshot.is_conflicted() {
        println!("The working copy's base has no conflicts.");
        return Ok(0);
    }
    let mut remaining = 0;
    for (p, f) in &snap.base_snapshot.files {
        if !f.is_conflicted() {
            continue;
        }
        match snap.statuses.iter().find(|s| s.path == *p).map(|s| s.status) {
            Some(ChangeStatus::Resolved) => println!("resolved   {p}"),
            Some(ChangeStatus::ConflictEdited) => {
                remaining += 1;
                println!("markers    {p}");
            }
            _ => {
                remaining += 1;
                println!("unresolved {p}");
            }
        }
    }
    for c in &snap.base_snapshot.tree.conflicts {
        remaining += 1;
        println!("tree       {c:?}");
    }
    if remaining == 0 {
        println!("All conflicts are resolved; `oxy commit` will record the resolution.");
        Ok(0)
    } else {
        Ok(2)
    }
}

pub fn undo() -> Result<i32> {
    let repo = open()?;
    let op = repo.undo()?;
    println!("{} now at: {}", ui::done("Undone;"), ui::dim(&op.command));
    Ok(0)
}

pub fn op_log(as_json: bool) -> Result<i32> {
    let repo = open()?;
    if as_json {
        let ops = repo.op_log()?;
        println!(
            "{}",
            json::arr(ops.iter().enumerate().map(|(i, (r, op))| {
                json::obj([
                    ("id", json::s(&r.to_hex())),
                    ("when_ms", json::n(op.hlc.wall_ms)),
                    ("command", json::s(&op.command)),
                    ("snapshot", json::b(op.command.ends_with("(snapshot)"))),
                    ("current", json::b(i == 0)),
                ])
            }))
        );
        return Ok(0);
    }
    for (i, (r, op)) in repo.op_log()?.into_iter().enumerate() {
        let bullet = if i == 0 { ui::ok(ui::glyph("●", "@")) } else { ui::dim(ui::glyph("○", "o")) };
        let cmd = subject_of(&op.command).split("\\n").next().unwrap_or("");
        println!("{bullet} {}{}{}  {}", ui::hash(r.short(12)), ui::sep(), ui::dim(format!("{:<16}", ui::ago(op.hlc.wall_ms))), if i == 0 { ui::subject(cmd) } else { cmd.to_string() });
    }
    Ok(0)
}

pub fn gc(now: bool) -> Result<i32> {
    let repo = open()?;
    let sp = ui::spinner("Packing and pruning…");
    let r = repo.gc(now)?;
    sp.clear();
    if r.packed.objects > 0 {
        println!(
            "Packed {}: {} bytes -> {} bytes ({:.0}%).",
            plural(r.packed.objects, "loose object"),
            r.packed.raw_bytes,
            r.packed.packed_bytes,
            100.0 * r.packed.packed_bytes as f64 / r.packed.raw_bytes.max(1) as f64
        );
    }
    println!("{} reachable; pruned {} ({} bytes){}{}; {} present.",
        plural(r.reachable, "object"),
        plural(r.pruned.objects, "unreachable object"),
        r.pruned.bytes,
        if r.pruned.deferred > 0 { format!("; {} deferred by the grace period (use --now)", plural(r.pruned.deferred, "object")) } else { String::new() },
        if r.merged_packs > 0 { format!("; merged {} into one", plural(r.merged_packs, "pack")) } else { String::new() },
        plural(repo.store().pack_count(), "pack")
    );
    Ok(0)
}

/// The single head the working copy sits on, for commands that default to it.
fn current_head(repo: &Repo) -> Result<oxy_core::hash::ChangeHash> {
    let snap = repo.snapshot("oxy")?;
    let base = snap.base.maximal(&snap.wc.deps);
    match base.as_slice() {
        [h] => Ok(*h),
        _ => anyhow::bail!("the working copy sits on {} heads; name the change explicitly", base.len()),
    }
}

pub fn describe(message: &str, change: Option<&str>) -> Result<i32> {
    let repo = open()?;
    let h = match change {
        Some(c) => repo.resolve_change(c)?,
        None => current_head(&repo)?,
    };
    let new = repo.describe(&h, message)?;
    let c = repo.store().get_change(&new)?;
    println!("{} {} {}  {}", ui::done("Described"), ui::id(short_id(&c)), ui::hash(format!("#{}", new.short(12))), ui::subject(subject_of(message)));
    Ok(0)
}

pub fn amend(message: Option<&str>, into: Option<&str>) -> Result<i32> {
    let repo = open()?;
    let new = match into {
        Some(spec) => {
            let target = repo.resolve_change(spec)?;
            repo.amend_into(&target, message)?
        }
        None => repo.amend(message)?,
    };
    let c = repo.store().get_change(&new)?;
    println!("{} {} {}  {}", ui::done("Amended"), ui::id(short_id(&c)), ui::hash(format!("#{}", new.short(12))), ui::subject(subject_of(&c.message)));
    Ok(0)
}

pub fn abandon(change: &str) -> Result<i32> {
    let repo = open()?;
    let h = repo.resolve_change(change)?;
    let c = repo.store().get_change(&h)?;
    let notes = repo.abandon(&h)?;
    println!("{} {} {}  {}", ui::done("Abandoned"), ui::id(short_id(&c)), ui::hash(format!("#{}", h.short(12))), ui::dim("its content remains on disk as uncommitted work if the working copy sat on it"));
    for n in notes {
        println!("  {} {n}", ui::note());
    }
    Ok(0)
}

pub fn checkpoint() -> Result<i32> {
    let repo = open()?;
    let sp = ui::spinner("Writing checkpoint…");
    let (r, changes, bytes) = repo.checkpoint()?;
    sp.done(&format!("{} {} of {} ({} bytes) for {}", ui::done("Checkpoint"), ui::hash(format!("#{}", r.short(12))), plural(changes, "change"), bytes, ui::id(&repo.config.bookmark)));
    Ok(0)
}

/// For shell prompts: silent (exit 1) outside a repository, otherwise one line.
pub fn prompt(format: &str, glyphs: bool, color: Option<&str>) -> Result<i32> {
    let Ok(repo) = Repo::open(&std::env::current_dir()?) else { return Ok(1) };
    let info = repo.quick_status()?;
    let fmt = if glyphs && format == oxy_core::repo::DEFAULT_PROMPT_FORMAT { oxy_core::repo::GLYPH_PROMPT_FORMAT } else { format };
    let line = match color {
        Some("bash") => info.format_colored(fmt, ("\\[", "\\]")),
        Some("zsh") => info.format_colored(fmt, ("%{", "%}")),
        Some(_) => info.format_colored(fmt, ("", "")),
        None => info.format(fmt),
    };
    println!("{line}");
    Ok(0)
}

pub fn sparse(paths: &[String]) -> Result<i32> {
    let mut repo = open()?;
    if paths.is_empty() {
        if repo.config.sparse_paths.is_empty() {
            println!("No sparse filter: the whole tree is materialized.");
        } else {
            println!("{}", ui::heading("Sparse filter"));
            for p in &repo.config.sparse_paths {
                println!("  {}", ui::path(p));
            }
        }
        return Ok(0);
    }
    let snap = repo.snapshot("oxy sparse")?;
    if !snap.wc.tree_ops.is_empty() || !snap.wc.edits.is_empty() {
        anyhow::bail!("the working copy has changes; commit them before changing the sparse filter");
    }
    repo.config.set("filter.paths", &paths.join(","))?;
    repo.save_config()?;
    let heads = repo.bookmark_heads()?;
    let sp = ui::spinner("Re-checking out with the new filter…");
    let r = repo.checkout(&heads, true, "oxy sparse (checkout)")?;
    sp.done(&format!("{} {}: {} written, {} removed", ui::ok("Sparse filter set to"), ui::path(paths.join(",")), plural(r.written, "file"), r.removed));
    Ok(0)
}

pub fn tag_create(name: &str, changes: &[String], message: &str) -> Result<i32> {
    let repo = open()?;
    repo.snapshot("oxy tag")?;
    let heads = if changes.is_empty() {
        repo.bookmark_heads()?
    } else {
        let mut heads = Vec::new();
        for c in changes {
            heads.extend(repo.resolve_heads(c)?);
        }
        heads
    };
    let t = repo.tag_create(name, &heads, message)?;
    println!(
        "{} {} {} {} ({}){}",
        ui::done("Tagged"),
        ui::bookmark(&t.name),
        ui::dim(ui::glyph("→", "->")),
        ui::hash(format!("#{}", t.state.short(12))),
        plural(t.heads.len(), "head"),
        t.signer.map(|s| format!(", signed by {s}")).unwrap_or_else(|| ui::dim(", unsigned"))
    );
    Ok(0)
}

pub fn tag_list() -> Result<i32> {
    let repo = open()?;
    let tags = repo.tags()?;
    if tags.is_empty() {
        println!("{}", ui::dim("No tags."));
    }
    for t in tags {
        println!(
            "{} {} {}{}{}{}",
            ui::ok(ui::glyph("⚑", "#")),
            ui::bookmark(&t.name),
            ui::hash(format!("#{}", t.state.short(12))),
            ui::sep() + &ui::dim(plural(t.heads.len(), "head")),
            if t.message.is_empty() { String::new() } else { format!("  {}", ui::subject(subject_of(&t.message))) },
            t.signer.map(|s| ui::sep() + &ui::ok(format!("{} {s}", ui::glyph("✔", "v")))).unwrap_or_default()
        );
    }
    Ok(0)
}

pub fn workspace_add(path: &std::path::Path, changes: &[String]) -> Result<i32> {
    let repo = open()?;
    let heads = if changes.is_empty() {
        None
    } else {
        let mut heads = Vec::new();
        for c in changes {
            heads.extend(repo.resolve_heads(c)?);
        }
        Some(heads)
    };
    let sp = ui::spinner(&format!("Creating workspace at {}…", path.display()));
    let ws = repo.workspace_add(path, heads.as_deref())?;
    sp.done(&format!("{} {} (workspace {})", ui::done("Workspace created at"), ui::path(ws.root().display()), ui::id(ws.workspace().short(8))));
    Ok(0)
}

pub fn workspace_list() -> Result<i32> {
    let repo = open()?;
    for w in repo.workspaces()? {
        println!(
            "{} {} {}{}",
            if w.current { ui::ok(ui::glyph("●", "*")) } else { ui::dim(ui::glyph("○", "o")) },
            ui::id(w.id.short(8)),
            ui::path(w.path.display()),
            w.working_copy.map(|h| ui::sep() + &ui::dim(format!("working copy #{}", h.short(12)))).unwrap_or_else(|| ui::sep() + &ui::warn("not in view"))
        );
    }
    Ok(0)
}

pub fn workspace_forget(spec: &str) -> Result<i32> {
    let repo = open()?;
    let all = repo.workspaces()?;
    let target = std::fs::canonicalize(spec).ok();
    let matches: Vec<_> = all.iter().filter(|w| w.id.starts_with_hex(spec) || target.as_ref().is_some_and(|t| *t == w.path)).collect();
    let w = match matches.as_slice() {
        [w] => *w,
        [] => anyhow::bail!("no workspace matches {spec:?}"),
        _ => anyhow::bail!("{spec:?} is ambiguous"),
    };
    repo.workspace_forget(&w.id)?;
    println!("{} workspace {} at {}; its files were left in place.", ui::done("Forgot"), ui::id(w.id.short(8)), ui::path(w.path.display()));
    Ok(0)
}

pub fn lock(path: &str) -> Result<i32> {
    let repo = open()?;
    repo.lock_path(path)?;
    println!("{} {} {}", ui::done("Locked"), ui::path(path), ui::dim("(advisory, local)"));
    Ok(0)
}

pub fn unlock(path: &str) -> Result<i32> {
    let repo = open()?;
    repo.unlock_path(path)?;
    println!("{} {}", ui::done("Unlocked"), ui::path(path));
    Ok(0)
}

pub fn split(change: &str, paths: &[String]) -> Result<i32> {
    let repo = open()?;
    let h = repo.resolve_change(change)?;
    let (h1, h2) = repo.split(&h, paths)?;
    let c1 = repo.store().get_change(&h1)?;
    let c2 = repo.store().get_change(&h2)?;
    println!("{} into {} {} and {} {}", ui::done("Split"), ui::id(short_id(&c1)), ui::hash(format!("#{}", h1.short(12))), ui::id(short_id(&c2)), ui::hash(format!("#{}", h2.short(12))));
    Ok(0)
}

fn heads_from(repo: &Repo, changes: &[String]) -> Result<Vec<oxy_core::hash::ChangeHash>> {
    let mut heads = Vec::new();
    for c in changes {
        heads.extend(repo.resolve_heads(c)?);
    }
    Ok(heads)
}

pub fn bookmark_create(name: &str, changes: &[String]) -> Result<i32> {
    let repo = open()?;
    repo.snapshot("oxy bookmark create")?;
    let heads = if changes.is_empty() { None } else { Some(heads_from(&repo, changes)?) };
    let heads = repo.bookmark_create(name, heads.as_deref())?;
    println!("{} bookmark {} {} {}", ui::done("Created"), ui::bookmark(name), ui::dim(ui::glyph("→", "->")), ui::dim(plural(heads.len(), "head")));
    println!("  {} {}", ui::note(), ui::dim(format!("switch to it with oxy bookmark switch {name}")));
    Ok(0)
}

pub fn bookmark_set(name: &str, changes: &[String]) -> Result<i32> {
    let repo = open()?;
    repo.snapshot("oxy bookmark set")?;
    let heads = heads_from(&repo, changes)?;
    let heads = repo.bookmark_set(name, &heads)?;
    println!("{} bookmark {} {} {}", ui::done("Moved"), ui::bookmark(name), ui::dim(ui::glyph("→", "->")), ui::dim(plural(heads.len(), "head")));
    Ok(0)
}

pub fn bookmark_delete(name: &str) -> Result<i32> {
    let repo = open()?;
    repo.bookmark_delete(name)?;
    println!("{} bookmark {} {}", ui::done("Deleted"), ui::bookmark(name), ui::dim("(its changes stay until unreachable)"));
    Ok(0)
}

pub fn bookmark_list(as_json: bool) -> Result<i32> {
    let repo = open()?;
    if as_json {
        let items = repo.bookmarks()?.into_iter().map(|b| {
            json::obj([
                ("name", json::s(&b.name)),
                ("heads", json::hashes(&b.heads)),
                ("current", json::b(b.current)),
                ("ahead", json::opt(b.ahead, json::n)),
                ("behind", json::opt(b.behind, json::n)),
            ])
        });
        println!("{}", json::arr(items));
        return Ok(0);
    }
    for b in repo.bookmarks()? {
        let mark = if b.current { ui::ok(ui::glyph("●", "*")) } else { ui::dim(ui::glyph("○", "o")) };
        let mut tail = String::new();
        if let Some(n) = b.ahead.filter(|n| *n > 0) {
            tail += &ui::ok(format!(" {}{n}", ui::glyph("↑", "+")));
        }
        if let Some(n) = b.behind.filter(|n| *n > 0) {
            tail += &ui::warn(format!(" {}{n}", ui::glyph("↓", "-")));
        }
        let head = b.heads.first().map(|h| repo.store().get_change(h).map(|c| ui::subject(subject_of(&c.message))).unwrap_or_default()).unwrap_or_else(|| ui::dim("(empty)"));
        println!("{mark} {}{}{}{tail}  {head}", ui::bookmark(&b.name), ui::sep(), ui::dim(plural(b.heads.len(), "head")));
    }
    Ok(0)
}

pub fn bookmark_switch(name: &str, discard: bool) -> Result<i32> {
    let mut repo = open()?;
    let sp = ui::spinner(&format!("Switching to {name}…"));
    let r = repo.bookmark_switch(name, discard)?;
    sp.done(&format!("{} to {}: {} written, {} removed", ui::done("Switched"), ui::bookmark(name), plural(r.written, "file"), r.removed));
    if r.conflicted {
        println!("  {} {}", ui::caution(), ui::warn("this state has conflicts; see oxy status"));
    }
    Ok(0)
}

pub fn merge(bookmark: &str) -> Result<i32> {
    let repo = open()?;
    let sp = ui::spinner(&format!("Merging {bookmark}…"));
    let r = repo.merge(bookmark)?;
    if !r.changed {
        sp.done(&format!("{} {}", ui::ok(ui::glyph("✔", "*")), ui::dim(format!("{} already contains {bookmark}", repo.config.bookmark))));
        return Ok(0);
    }
    sp.done(&format!(
        "{} {} into {}: now {}{}",
        ui::done("Merged"),
        ui::bookmark(bookmark),
        ui::bookmark(&repo.config.bookmark),
        plural(r.heads.len(), "head"),
        ui::dim(if r.checked_out { "; working copy updated" } else { "; run oxy checkout to update the working copy" })
    ));
    let snap = repo.snapshot("oxy merge")?;
    if snap.base_snapshot.is_conflicted() {
        println!("  {} {}", ui::caution(), ui::warn("the result has conflicts; see oxy status"));
    }
    Ok(0)
}

pub fn squash(change: &str, into: &str) -> Result<i32> {
    let repo = open()?;
    let c = repo.resolve_change(change)?;
    let d = repo.resolve_change(into)?;
    let sp = ui::spinner("Squashing…");
    let h = repo.squash(&c, &d)?;
    let new = repo.store().get_change(&h)?;
    sp.done(&format!("{} into {} {}  {}", ui::done("Squashed"), ui::id(short_id(&new)), ui::hash(format!("#{}", h.short(12))), ui::subject(subject_of(&new.message))));
    Ok(0)
}

pub fn rebase(change: &str, onto: &[String]) -> Result<i32> {
    let repo = open()?;
    let c = repo.resolve_change(change)?;
    let mut heads = Vec::new();
    for o in onto {
        heads.extend(repo.resolve_heads(o)?);
    }
    let sp = ui::spinner("Rebasing…");
    let h = repo.rebase(&c, &heads)?;
    let new = repo.store().get_change(&h)?;
    sp.done(&format!("{} {} {}  {}", ui::done("Rebased"), ui::id(short_id(&new)), ui::hash(format!("#{}", h.short(12))), ui::dim(format!("now depends on {}", plural(new.deps.len(), "change")))));
    Ok(0)
}