//! Identity, verification, and configuration commands.

use super::format::{short_id, signature_line, when};
use super::json;
use super::open;
use super::ui;
use anyhow::Result;
use oxy_core::hash::ChangeHash;
use oxy_core::hash::KeyId;
use oxy_core::identity::Identity;
use oxy_core::objects::Hlc;
use oxy_core::protocol::SignedPolicy;
use oxy_core::repo::{self, IdentityScope, PolicyUpdate, Repo, Rotation, SignatureStatus};
use std::path::{Path, PathBuf};

const DAY_MS: u64 = 24 * 60 * 60 * 1000;

fn expiry_from_days(days: u64) -> Option<u64> {
    (days > 0).then(|| Hlc::now().wall_ms + days * DAY_MS)
}

/// Resolve a KeyId prefix among the identities the repository knows.
fn resolve_key(repo: &Repo, prefix: &str) -> Result<KeyId> {
    if let Some(k) = KeyId::from_hex(prefix) {
        return Ok(k);
    }
    let mut candidates: Vec<KeyId> = Vec::new();
    if let Some((_, sp)) = repo.current_policy()? {
        candidates.extend(sp.policy.identities.iter().map(|i| i.hash()));
        candidates.extend(sp.policy.revoked.iter().copied());
    }
    if let Some(own) = repo.config.author_key {
        candidates.push(own);
        if let Ok(id) = repo.identity(&own) {
            candidates.extend(id.delegates.iter().copied());
        }
    }
    candidates.sort();
    candidates.dedup();
    let matches: Vec<_> = candidates
        .into_iter()
        .filter(|k| k.starts_with_hex(prefix))
        .collect();
    match matches.len() {
        1 => Ok(matches[0]),
        0 => anyhow::bail!("no known key starts with {prefix:?}"),
        _ => anyhow::bail!("{prefix:?} is ambiguous"),
    }
}

/// Report a policy update: applied, or written out as a proposal that
/// other root holders sign with `oxy policy sign`.
fn report_update(u: &PolicyUpdate, out: Option<PathBuf>) -> Result<()> {
    if u.applied {
        println!(
            "{} policy serial {} {}",
            ui::done("Applied"),
            u.policy.serial,
            ui::dim("(push to publish it)")
        );
        return Ok(());
    }
    let path = out.unwrap_or_else(|| PathBuf::from(format!("policy-{}.proposal", u.policy.serial)));
    std::fs::write(&path, u.signed().encode())?;
    println!(
        "{} policy serial {} needs {} of {} root signatures; has {}. Wrote {} for another root to run {}",
        ui::caution(),
        u.policy.serial,
        u.policy.root_threshold,
        u.policy.roots.len(),
        u.sigs.len(),
        ui::path(path.display()),
        ui::dim(format!("oxy policy sign {}", path.display()))
    );
    Ok(())
}

fn report_rotation(r: &Rotation, verb: &str) -> Result<()> {
    println!(
        "{} identity {} <{}>",
        ui::done(verb),
        ui::author(&r.identity.name),
        r.identity.email
    );
    println!("{}", ui::kv("old key", ui::dim(r.old.to_hex())));
    println!("{}", ui::kv("new key", r.new.to_hex()));
    if !r.identity.delegates.is_empty() {
        println!(
            "{}",
            ui::kv(
                "delegates",
                r.identity
                    .delegates
                    .iter()
                    .map(|d| d.short(12))
                    .collect::<Vec<_>>()
                    .join(" ")
            )
        );
    }
    if let Some(e) = r.identity.expires {
        println!("{}", ui::kv("expires", when(e)));
    }
    match &r.policy {
        Some(u) => report_update(u, None)?,
        None => println!(
            "  {} {}",
            ui::note(),
            ui::dim("no policy names the old key; export the new identity for policy holders")
        ),
    }
    Ok(())
}

pub fn create(
    name: Option<String>,
    email: Option<String>,
    local: bool,
    expires: Option<u64>,
) -> Result<i32> {
    let mut repo = open()?;
    let name = name.unwrap_or_else(|| repo.config.author_name.clone());
    let email = email.unwrap_or_else(|| repo.config.author_email.clone());
    let scope = if local {
        IdentityScope::Repo
    } else {
        IdentityScope::User
    };
    let (key, _) =
        repo.create_identity_with(&name, &email, scope, expires.and_then(expiry_from_days))?;
    println!(
        "{} identity {} <{email}>",
        ui::done("Created"),
        ui::author(&name)
    );
    println!("{}", ui::kv("key", key));
    println!(
        "{}",
        ui::kv("secret", ui::path(repo::default_keys_dir().display()))
    );
    match scope {
        IdentityScope::User => println!(
            "{}",
            ui::kv(
                "scope",
                format!(
                    "default author in {}",
                    ui::path(repo.user_config_path().display())
                )
            )
        ),
        IdentityScope::Repo => {
            println!("{}", ui::kv("scope", "this repository's .oxy/config only"))
        }
    }
    if !repo.config.sign_changes {
        println!("  {} {}", ui::note(), ui::dim("changes will carry this author; run oxy config --user core.sign change to sign each commit"));
    }
    Ok(0)
}

pub fn show() -> Result<i32> {
    let repo = open()?;
    let Some(key) = repo.config.author_key else {
        println!("No identity configured; run `oxy identity create`.");
        return Ok(0);
    };
    let id = repo.identity(&key)?;
    println!(
        "{} {} <{}>",
        ui::section("identity"),
        ui::author(&id.name),
        id.email
    );
    println!("{}", ui::kv("key", key));
    println!(
        "{}",
        ui::kv(
            "created",
            format!(
                "{} {}",
                when(id.created),
                ui::dim(format!("({})", ui::ago(id.created)))
            )
        )
    );
    if let Some(e) = id.expires {
        let expired = id.is_expired_at(Hlc::now().wall_ms);
        println!(
            "{}",
            ui::kv(
                "expires",
                if expired {
                    ui::err(format!("{} EXPIRED", when(e)))
                } else {
                    when(e)
                }
            )
        );
    }
    if let Some(p) = id.previous {
        println!("{}", ui::kv("previous", ui::dim(p.short(12))));
    }
    if !id.delegates.is_empty() {
        println!(
            "{}",
            ui::kv(
                "delegates",
                id.delegates
                    .iter()
                    .map(|d| d.short(12))
                    .collect::<Vec<_>>()
                    .join(" ")
            )
        );
    }
    if repo.is_revoked(&key)? {
        println!(
            "{}",
            ui::kv(
                "status",
                ui::err(format!("{} REVOKED", ui::glyph("✖", "x")))
            )
        );
    }
    println!(
        "{}",
        ui::kv(
            "secret",
            if repo.secret_key()?.is_some() {
                ui::ok(format!("{} available", ui::glyph("✔", "*")))
            } else {
                ui::err(format!(
                    "{} not found in the key directory",
                    ui::glyph("✖", "x")
                ))
            }
        )
    );
    println!(
        "{}",
        ui::kv(
            "signing",
            if repo.config.sign_changes {
                "every change (core.sign = change)"
            } else {
                "at push via seals (core.sign = seal)"
            }
        )
    );
    Ok(0)
}

pub fn verify(change: Option<&str>, as_json: bool) -> Result<i32> {
    let repo = open()?;
    let hashes: Vec<ChangeHash> = match change {
        Some(c) => vec![repo.resolve_change(c)?],
        None => repo
            .log()?
            .into_iter()
            .filter(|e| !e.is_working_copy)
            .map(|e| e.hash)
            .collect(),
    };
    let mut bad = 0;
    if as_json {
        let mut items = Vec::new();
        for h in &hashes {
            let Ok(c) = repo.store().get_change(h) else {
                continue;
            };
            let (status, key, name, revoked, reason) = match repo.authenticate_change(h)? {
                SignatureStatus::Unsigned => ("unsigned", None, None, false, None),
                SignatureStatus::Valid {
                    key,
                    name,
                    sealed,
                    revoked,
                    ..
                } => (
                    if sealed { "sealed" } else { "signed" },
                    Some(key.to_hex()),
                    Some(name),
                    revoked,
                    None,
                ),
                SignatureStatus::Invalid(why) => {
                    bad += 1;
                    ("invalid", None, None, false, Some(why))
                }
            };
            items.push(json::obj([
                ("hash", json::s(&h.to_hex())),
                ("change_id", json::s(&c.change_id.to_hex())),
                ("status", json::s(status)),
                ("key", json::opt(key.as_deref(), json::s)),
                ("name", json::opt(name.as_deref(), json::s)),
                ("revoked", json::b(revoked)),
                ("reason", json::opt(reason.as_deref(), json::s)),
            ]));
        }
        println!("{}", json::arr(items));
        return Ok(if bad > 0 { 1 } else { 0 });
    }
    for h in hashes {
        let Ok(c) = repo.store().get_change(&h) else {
            println!(
                "{}  {}",
                ui::hash(format!("#{}", h.short(12))),
                ui::dim("not present (shallow)")
            );
            continue;
        };
        let line = signature_line(&repo, &h)?;
        let styled = if line.starts_with("INVALID") {
            bad += 1;
            ui::err(format!("{} {line}", ui::glyph("✖", "x")))
        } else if line == "unsigned" {
            ui::dim(format!("{} {line}", ui::glyph("·", "-")))
        } else {
            ui::ok(format!("{} {line}", ui::glyph("✔", "v")))
        };
        println!(
            "{} {}  {styled}",
            ui::id(short_id(&c)),
            ui::hash(format!("#{}", h.short(12)))
        );
    }
    Ok(if bad > 0 { 1 } else { 0 })
}

pub fn config(key: &str, value: &str, user: bool) -> Result<i32> {
    if user {
        let path = repo::default_user_config();
        repo::Config::set_user(&path, key, value)?;
        println!(
            "{} {key} = {value} {}",
            ui::done("Set"),
            ui::dim(format!("(in {})", path.display()))
        );
    } else {
        let mut repo = open()?;
        repo.config.set(key, value)?;
        repo.save_config()?;
        println!(
            "{} {key} = {value} {}",
            ui::done("Set"),
            ui::dim("(in this repository)")
        );
    }
    Ok(0)
}

pub fn export(path: Option<PathBuf>) -> Result<i32> {
    let repo = open()?;
    let Some(key) = repo.config.author_key else {
        anyhow::bail!("no identity configured; run `oxy identity create`");
    };
    let id = repo.identity(&key)?;
    let path = path.unwrap_or_else(|| PathBuf::from(format!("{}.identity", key.short(16))));
    std::fs::write(&path, id.encode())?;
    println!(
        "{} identity {} <{}> ({}) to {}",
        ui::done("Wrote"),
        ui::author(&id.name),
        id.email,
        key.short(12),
        ui::path(path.display())
    );
    Ok(0)
}

pub fn rotate() -> Result<i32> {
    let mut repo = open()?;
    let r = repo.rotate_identity()?;
    report_rotation(&r, "Rotated")?;
    Ok(0)
}

pub fn renew(expires: u64) -> Result<i32> {
    let mut repo = open()?;
    let r = repo.renew_identity(expiry_from_days(expires))?;
    report_rotation(&r, "Renewed")?;
    Ok(0)
}

pub fn revoke(key: Option<&str>, reason: &str) -> Result<i32> {
    let repo = open()?;
    let key = match key {
        Some(k) => resolve_key(&repo, k)?,
        None => repo
            .config
            .author_key
            .ok_or_else(|| anyhow::anyhow!("no identity configured"))?,
    };
    let update = repo.revoke_identity(&key, reason)?;
    println!(
        "{} key {}{}",
        ui::done("Revoked"),
        ui::hash(key.short(12)),
        if reason.is_empty() {
            String::new()
        } else {
            format!(": {reason}")
        }
    );
    match update {
        Some(u) => report_update(&u, None)?,
        None => println!(
            "  {} {}",
            ui::note(),
            ui::dim("recorded locally; no policy named the key")
        ),
    }
    if repo.config.author_key == Some(key) {
        println!(
            "  {} {}",
            ui::caution(),
            ui::warn("this was your configured key; run oxy identity create or rotate")
        );
    }
    Ok(0)
}

pub fn delegate_add(identity_file: &Path) -> Result<i32> {
    let mut repo = open()?;
    let id = Identity::decode(&std::fs::read(identity_file)?)?;
    let r = repo.delegate_add(id)?;
    report_rotation(&r, "Delegated")?;
    Ok(0)
}

pub fn delegate_remove(key: &str) -> Result<i32> {
    let mut repo = open()?;
    let k = resolve_key(&repo, key)?;
    let r = repo.delegate_remove(&k)?;
    report_rotation(&r, "Undelegated")?;
    Ok(0)
}

pub fn delegate_list() -> Result<i32> {
    let repo = open()?;
    let Some(key) = repo.config.author_key else {
        println!("No identity configured; run `oxy identity create`.");
        return Ok(0);
    };
    let id = repo.identity(&key)?;
    if id.delegates.is_empty() {
        println!("{}", ui::dim("No delegates."));
    }
    for d in &id.delegates {
        let who = repo
            .identity(d)
            .map(|i| format!("{} <{}>", i.name, i.email))
            .unwrap_or_else(|_| "(unknown identity)".into());
        println!(
            "  {} {}  {}",
            ui::ok(ui::glyph("🔑", "*")),
            ui::hash(d.short(12)),
            ui::author(who)
        );
    }
    Ok(0)
}

pub fn policy_root_add(identity_file: &Path, out: Option<PathBuf>) -> Result<i32> {
    let repo = open()?;
    let id = Identity::decode(&std::fs::read(identity_file)?)?;
    let key = id.hash();
    let u = repo.policy_root_add(id.clone())?;
    println!(
        "{} root {} <{}> ({})",
        ui::done("Added"),
        ui::author(&id.name),
        id.email,
        key.short(12)
    );
    report_update(&u, out)?;
    Ok(0)
}

pub fn policy_root_remove(key: &str, out: Option<PathBuf>) -> Result<i32> {
    let repo = open()?;
    let k = resolve_key(&repo, key)?;
    let u = repo.policy_root_remove(&k)?;
    println!("{} root {}", ui::done("Removed"), ui::hash(k.short(12)));
    report_update(&u, out)?;
    Ok(0)
}

pub fn policy_threshold(n: u32, out: Option<PathBuf>) -> Result<i32> {
    let repo = open()?;
    let u = repo.policy_set_threshold(n)?;
    println!("{} root threshold to {n}", ui::done("Set"));
    report_update(&u, out)?;
    Ok(0)
}

pub fn policy_sign(proposal: &Path, out: Option<PathBuf>) -> Result<i32> {
    let repo = open()?;
    let sp = SignedPolicy::decode(&std::fs::read(proposal)?)?;
    let u = repo.policy_sign(sp)?;
    println!("{} policy serial {}", ui::done("Signed"), u.policy.serial);
    report_update(&u, Some(out.unwrap_or_else(|| proposal.to_path_buf())))?;
    Ok(0)
}

pub fn policy_init() -> Result<i32> {
    let repo = open()?;
    let sp = repo.policy_init()?;
    println!(
        "{} policy with root key {}",
        ui::done("Created"),
        sp.policy.roots[0].short(12)
    );
    report_update(&sp, None)?;
    Ok(0)
}

pub fn policy_show(as_json: bool) -> Result<i32> {
    let repo = open()?;
    let Some((r, sp)) = repo.current_policy()? else {
        if as_json {
            println!("null");
        } else {
            println!(
                "No policy: this repository is unverified. Run `oxy policy init` to create one."
            );
        }
        return Ok(0);
    };
    let p = &sp.policy;
    if as_json {
        let ident = |k: &oxy_core::hash::KeyId| {
            let (name, email) = p
                .identity(k)
                .map(|i| (i.name.clone(), i.email.clone()))
                .unwrap_or_default();
            json::obj([
                ("key", json::s(&k.to_hex())),
                ("name", json::s(&name)),
                ("email", json::s(&email)),
            ])
        };
        println!(
            "{}",
            json::obj([
                ("hash", json::s(&r.to_hex())),
                ("serial", json::n(p.serial)),
                ("expires_ms", json::n(p.expires)),
                (
                    "expired",
                    json::b(p.is_expired(oxy_core::objects::Hlc::now().wall_ms))
                ),
                ("root_threshold", json::n(p.root_threshold)),
                ("roots", json::arr(p.roots.iter().map(ident))),
                (
                    "rules",
                    json::arr(p.rules.iter().map(|rule| {
                        json::obj([
                            ("pattern", json::s(&rule.pattern)),
                            ("keys", json::arr(rule.keys.iter().map(ident))),
                            ("threshold", json::n(rule.threshold)),
                            ("require", json::s(rule.require.name())),
                            ("allow_conflicts", json::b(rule.allow_conflicts)),
                        ])
                    })),
                ),
                ("revoked", json::arr(p.revoked.iter().map(ident))),
            ])
        );
        return Ok(0);
    }
    let name = |k: &oxy_core::hash::KeyId| {
        p.identity(k)
            .map(|i| format!("{} <{}>", i.name, i.email))
            .unwrap_or_else(|| "(unknown identity)".into())
    };
    let expired = p.is_expired(oxy_core::objects::Hlc::now().wall_ms);
    println!(
        "{} {}{}serial {}{}expires {}{}",
        ui::section("policy"),
        ui::hash(format!("#{}", r.short(12))),
        ui::sep(),
        p.serial,
        ui::sep(),
        when(p.expires),
        if expired {
            ui::err(format!("  {} EXPIRED", ui::glyph("✖", "x")))
        } else {
            String::new()
        }
    );
    println!(
        "{}",
        ui::section(format!(
            "roots {}",
            ui::dim(format!("(threshold {})", p.root_threshold))
        ))
    );
    for k in &p.roots {
        println!(
            "  {} {}  {}",
            ui::ok(ui::glyph("🔑", "*")),
            ui::hash(k.short(12)),
            ui::author(name(k))
        );
    }
    println!("{}", ui::section("rules"));
    for rule in &p.rules {
        println!(
            "  {} {:12} {}",
            ui::ok(ui::glyph("▸", ">")),
            ui::bookmark(&rule.pattern),
            ui::dim(format!(
                "threshold {}, require {}, conflicts {}",
                rule.threshold,
                rule.require.name(),
                if rule.allow_conflicts {
                    "allowed"
                } else {
                    "refused"
                }
            ))
        );
        for k in &rule.keys {
            println!("      {}  {}", ui::hash(k.short(12)), ui::author(name(k)));
        }
    }
    if !p.revoked.is_empty() {
        println!("{}", ui::section("revoked"));
        for k in &p.revoked {
            println!(
                "  {} {}  {}",
                ui::err(ui::glyph("✖", "x")),
                ui::hash(k.short(12)),
                ui::author(name(k))
            );
        }
    }
    Ok(0)
}

pub fn policy_grant(
    identity_file: &Path,
    pattern: Option<&str>,
    out: Option<PathBuf>,
) -> Result<i32> {
    let repo = open()?;
    let id = Identity::decode(&std::fs::read(identity_file)?)?;
    let key = id.hash();
    let u = repo.policy_grant(id.clone(), pattern)?;
    println!(
        "{} {} <{}> ({}) on {}",
        ui::done("Granted"),
        ui::author(&id.name),
        id.email,
        key.short(12),
        ui::bookmark(pattern.unwrap_or("*"))
    );
    report_update(&u, out)?;
    Ok(0)
}

pub fn policy_revoke(key: &str, out: Option<PathBuf>) -> Result<i32> {
    let repo = open()?;
    if repo.current_policy()?.is_none() {
        anyhow::bail!("this repository has no policy");
    }
    let full = resolve_key(&repo, key)?;
    let u = repo.policy_revoke(&full)?;
    println!("{} {}", ui::done("Revoked"), ui::hash(full.short(12)));
    report_update(&u, out)?;
    Ok(0)
}

/// `oxy seal [CHANGE..]`: seal the named changes, or every sealable one.
pub fn seal(specs: &[String], as_json: bool) -> Result<i32> {
    let repo = Repo::open(&std::env::current_dir()?)?;
    let hashes: Vec<_> = if specs.is_empty() {
        repo.sealable()?
    } else {
        specs
            .iter()
            .map(|s| repo.resolve_change(s))
            .collect::<std::result::Result<_, _>>()?
    };
    if hashes.is_empty() {
        if as_json {
            println!("{{\"sealed\":[]}}");
        } else {
            println!(
                "{} nothing to seal: every change you can authenticate already is",
                ui::done("Sealed")
            );
        }
        return Ok(0);
    }
    let mut refs = Vec::new();
    for chunk in hashes.chunks(oxy_core::attest::MAX_SEAL_HASHES) {
        refs.push(repo.seal(chunk)?);
    }
    if as_json {
        let list: Vec<String> = hashes
            .iter()
            .map(|h| format!("\"{}\"", h.to_hex()))
            .collect();
        let seals: Vec<String> = refs.iter().map(|r| format!("\"{}\"", r.to_hex())).collect();
        println!(
            "{{\"sealed\":[{}],\"seals\":[{}]}}",
            list.join(","),
            seals.join(",")
        );
    } else {
        println!(
            "{} {} change{} in {} seal{}; they travel with your next push",
            ui::done("Sealed"),
            hashes.len(),
            if hashes.len() == 1 { "" } else { "s" },
            refs.len(),
            if refs.len() == 1 { "" } else { "s" }
        );
        for h in &hashes {
            let title = repo
                .store()
                .get_change(h)
                .map(|c| c.message.lines().next().unwrap_or("").to_string())
                .unwrap_or_default();
            println!("  {} {}", ui::hash(h.short(12)), title);
        }
    }
    Ok(0)
}