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

use super::format::{deps_line, plural, short_id, signature_line, when};

use super::open;

use anyhow::Result;

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!("Initialized oxy repository in {}", repo.root().display());

    println!("Bookmark: {}   Author: {} <{}>", repo.config.bookmark, 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::ModeChanged => "X",

        ChangeStatus::ConflictEdited => "C!",

        ChangeStatus::Resolved => "R",

    }

}

pub fn status() -> Result<i32> {

    let repo = open()?;

    let snap = repo.snapshot("oxy status")?;

    let heads = repo.bookmark_heads()?;

    println!("Working copy: {} on {} ({})", snap.wc.change_id.short(8), repo.config.bookmark, plural(heads.len(), "head"));

    if snap.statuses.is_empty() {

        println!("The working copy is clean.");

    }

    for s in &snap.statuses {

        println!("{:2} {}", status_tag(s.status), s.path);

    }

    if !snap.base_snapshot.is_conflicted() {

        return Ok(0);

    }

    println!("\nConflicts in the base state (edit the marked files, or the .oxy-conflict-N candidates, then commit):");

    for c in &snap.base_snapshot.tree.conflicts {

        println!("  tree: {c:?}");

    }

    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) => "resolved in working copy",

                Some(ChangeStatus::ConflictEdited) => "markers remain",

                _ => "unresolved",

            };

            println!("  {p}  ({state})");

        }

    }

    Ok(2)

}

pub fn commit(message: &str, depends_on: &[String]) -> Result<i32> {

    let repo = open()?;

    let mut deps = Vec::new();

    for d in depends_on {

        deps.push(repo.resolve_change(d)?);

    }

    let h = repo.commit(message, &deps)?;

    let c = repo.store().get_change(&h)?;

    println!("Committed {} #{}: {}", short_id(&c), h.short(12), message.lines().next().unwrap_or(""));

    Ok(0)

}

pub fn log() -> Result<i32> {

    let repo = open()?;

    repo.snapshot("oxy log")?;

    for e in repo.log()? {

        let c = &e.change;

        let mut flags = Vec::new();

        if e.is_working_copy {

            flags.push("working copy");

        }

        if e.is_head {

            flags.push("head");

        }

        let flags = if flags.is_empty() { String::new() } else { format!(" ({})", flags.join(", ")) };

        println!("{} #{}{}", short_id(c), e.hash.short(12), flags);

        println!("    {}", when(c.hlc.wall_ms));

        if !c.deps.is_empty() {

            println!("    deps: {}", deps_line(c));

        }

        let msg = if c.message.is_empty() { "(no description)" } else { &c.message };

        for line in msg.lines() {

            println!("    {line}");

        }

        println!();

    }

    Ok(0)

}

pub fn diff() -> Result<i32> {

    let repo = open()?;

    let snap = repo.snapshot("oxy diff")?;

    print!("{}", render_change(&snap.wc, &snap.base, &snap.base_snapshot));

    Ok(0)

}

pub fn show(change: &str) -> Result<i32> {

    let repo = open()?;

    repo.snapshot("oxy show")?;

    let h = repo.resolve_change(change)?;

    let c = repo.store().get_change(&h)?;

    println!("change {} #{}", short_id(&c), h);

    println!("kind:   {:?}", c.kind);

    println!("date:   {}", when(c.hlc.wall_ms));

    println!("deps:   {}", deps_line(&c));

    println!("sig:    {}", signature_line(&repo, &h)?);

    println!("\n{}\n", if c.message.is_empty() { "(no description)" } else { &c.message });

    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 {

        changes.iter().map(|c| repo.resolve_change(c)).collect::<Result<Vec<_>, _>>()?

    };

    let spec = if changes.is_empty() { repo.config.bookmark.clone() } else { changes.join(" ") };

    let r = repo.checkout(&heads, discard, &format!("oxy checkout {spec}"))?;

    println!("Working copy now on {spec}: {} written, {} removed", plural(r.written, "file"), r.removed);

    if r.conflicted {

        println!("This state has conflicts; see oxy status.");

    }

    Ok(0)

}

pub fn resolve() -> Result<i32> {

    let repo = open()?;

    let snap = repo.snapshot("oxy resolve")?;

    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!("Undid the last operation; now at: {}", op.command);

    Ok(0)

}

pub fn op_log() -> Result<i32> {

    let repo = open()?;

    for (i, (r, op)) in repo.op_log()?.into_iter().enumerate() {

        println!("{}{} {}  {}", if i == 0 { "@ " } else { "  " }, r.short(12), when(op.hlc.wall_ms), op.command);

    }

    Ok(0)

}

pub fn gc(now: bool) -> Result<i32> {

    let repo = open()?;

    let r = repo.gc(now)?;

    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() },

        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!("Described {} #{}: {}", short_id(&c), new.short(12), message.lines().next().unwrap_or(""));

    Ok(0)

}

pub fn amend(message: Option<&str>) -> Result<i32> {

    let repo = open()?;

    let new = repo.amend(message)?;

    let c = repo.store().get_change(&new)?;

    println!("Amended {} #{}: {}", short_id(&c), new.short(12), c.message.lines().next().unwrap_or(""));

    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)?;

    repo.abandon(&h)?;

    println!("Abandoned {} #{}; its content remains on disk as uncommitted work if the working copy sat on it.", short_id(&c), h.short(12));

    Ok(0)

}