//! `spectra agent`: agents as their owner's delegates (spec §8.1).

//!

//! `add` makes the agent's key pair in its own home, asks the owner to

//! confirm, signs the owner's successor that delegates to it, and records

//! both. There is no agent without an owner.

use super::identity::owner_home;

use super::{call, marks, ui, Ctx};

use anyhow::{bail, Context, Result};

use spectra_core::ids::now_ms;

use spectra_core::keys::{home_identity, KeyPair};

use spectra_core::ledger::Ledger;

use spectra_core::principals::{identity_payload, signed_event, Principal, Principals, DEFAULT_SCOPES};

use std::path::PathBuf;

pub const KINDS: &[&str] = &["claude-code", "antigravity", "kimi-code", "codex", "other"];

pub struct Add {

    pub name: String,

    pub kind: String,

    pub project: String,

    pub home: PathBuf,

    pub uid: Option<u32>,

    pub learn_uid: bool,

    pub expires: Option<String>,

    pub yes: bool,

    pub owner_home: Option<PathBuf>,

}

/// `30m`, `8h`, `7d` from now, in ms; `never` is none.

pub fn expiry(s: &str) -> Result<Option<u64>> {

    let s = s.trim();

    if s == "never" {

        return Ok(None);

    }

    let (n, unit) = s.split_at(s.find(|c: char| !c.is_ascii_digit()).unwrap_or(s.len()));

    let n: u64 = n.parse().with_context(|| format!("{s} is not a length of time (30m, 8h, 7d)"))?;

    let ms = match unit {

        "s" => n * 1000,

        "m" => n * 60_000,

        "h" => n * 3_600_000,

        "d" | "" => n * 86_400_000,

        _ => bail!("{s} is not a length of time (30m, 8h, 7d)"),

    };

    Ok(Some(now_ms() + ms))

}

/// Ask the owner at the terminal; `yes` answers for scripts.

pub fn confirm(question: &str, yes: bool) -> Result<()> {

    use std::io::IsTerminal;

    if yes {

        return Ok(());

    }

    if !std::io::stdin().is_terminal() {

        bail!("{question}: not asked, since this is not a terminal (--yes answers for a script)");

    }

    print!("{} {} {} ", ui::glyph("?", "?"), question, ui::dim("[y/N]"));

    use std::io::Write;

    std::io::stdout().flush().ok();

    let mut line = String::new();

    std::io::stdin().read_line(&mut line)?;

    if !matches!(line.trim().to_ascii_lowercase().as_str(), "y" | "yes") {

        bail!("not delegated: nothing was changed");

    }

    Ok(())

}

pub async fn add(ctx: &Ctx, a: Add) -> Result<i32> {

    if !valid_name(&a.name) {

        bail!("an agent's name is lower-case letters, digits and dashes, starting with a letter or digit, at most 64");

    }

    if !KINDS.contains(&a.kind.as_str()) {

        bail!("--kind is one of {}", KINDS.join(", "));

    }

    let home = owner_home(ctx, a.owner_home.clone());

    let (exists, known) = match ctx.owner_client(&home).await? {

        Some(c) => {

            let agents = call(&c, "GET", "/api/v1/agents", None).await?;

            let projects = call(&c, "GET", "/api/v1/projects", None).await?;

            let has = |v: &serde_json::Value, n: &str| v.as_array().is_some_and(|l| l.iter().any(|x| x["name"] == n));

            (has(&agents, &a.name), has(&projects, &a.project))

        }

        None => {

            let ledger = Ledger::open_read_only(&ctx.db()?).await?;

            let p = Principals::load(&ledger).await?;

            let known: Option<String> =

                sqlx::query_scalar("SELECT name FROM projects WHERE name = ?").bind(&a.project).fetch_optional(ledger.pool()).await?;

            (p.agent_key(&a.name).is_some(), known.is_some())

        }

    };

    if exists {

        bail!("an agent named {} already exists (spectra agent list)", a.name);

    }

    if !known {

        bail!("no project named {} (spectra project add PATH --name {})", a.project, a.project);

    }

    // The agent's key, made once in its own home and reused if `add` is run again.

    let agent = if a.home.join("keys").exists() {

        KeyPair::load_home(&a.home).with_context(|| format!("reading the agent's key in {}", a.home.display()))?

    } else {

        let pair = KeyPair::create_home(&a.home, &a.name, "")?;

        println!("{} {}  {}", ui::done("Created"), ui::subject(format!("{}'s key", a.name)), ui::path(a.home.display()));

        pair

    };

    let expires = a.expires.as_deref().map(expiry).transpose()?.flatten();

    let current = home_identity(&home)?;

    if current.delegate(&agent.key).map(|d| d.expires) != Some(expires) {

        let until = expires.map(|e| format!("until {}", super::format::when(e))).unwrap_or_else(|| "until you disable it".into());

        println!("{}", ui::kv("agent", format!("{}{}{}", ui::subject(&a.name), ui::sep(), ui::hash(agent.key.short(12)))));

        println!("{}", ui::kv("acts for", format!("{}{}{until}", ui::author(&current.name), ui::sep())));

        confirm(&format!("Let {} act for you", a.name), a.yes)?;

        spectra_core::keys::delegate(&home, agent.key, expires)?;

    }

    let w = ctx.owner_writer(&home).await?;

    let mut events: Vec<_> = w.refresh_event(&home).await?.into_iter().collect();

    let owner = KeyPair::load_home(&home)?;

    let mut p = identity_payload(&agent.identity);

    p["name"] = a.name.clone().into();

    p["kind"] = a.kind.into();

    p["project"] = a.project.into();

    p["home"] = a.home.display().to_string().into();

    p["owner"] = owner.key.to_hex().into();

    p["owner_name"] = owner.identity.name.clone().into();

    p["scopes"] = DEFAULT_SCOPES.into();

    if let Some(u) = a.uid {

        p["uid"] = u.into();

    }

    p["learn_uid"] = a.learn_uid.into();

    let d = owner.identity.delegate(&agent.key).context("the delegation vanished")?;

    p["delegation"] = serde_json::json!({ "expires": d.expires });

    events.push(signed_event(&owner, "human", "agent.added", p));

    w.append(events).await?;

    println!("{} {}{}{}", ui::done("Added"), ui::subject(&a.name), ui::sep(), ui::author(format!("{}'s agent", owner.identity.name)));

    println!("{}", ui::kv("key", ui::hash(agent.key.to_hex())));

    let until = d.expires.map(|e| format!("until {}", super::format::when(e))).unwrap_or_else(|| "until you disable it".into());

    println!("{}", ui::kv("delegated", until));

    // With Spectra on another machine the shim cannot look the home up.

    let shim = if ctx.remote()?.is_some() {

        format!("spectra mcp --agent {} --home {}", a.name, a.home.display())

    } else {

        format!("spectra mcp --agent {}", a.name)

    };

    println!("  {} {} {}", ui::note(), ui::dim("connect its client with"), ui::id(shim));

    Ok(0)

}

/// An agent as `agent list` reads it, with its presence.

#[derive(sqlx::FromRow)]

struct AgentRow {

    name: String,

    key: String,

    kind: String,

    project: String,

    disabled_ms: Option<i64>,

    presence: Option<String>,

    status: Option<String>,

}

pub async fn list(ctx: &Ctx, json: bool) -> Result<i32> {

    let out = match ctx.owner_client(&owner_home(ctx, None)).await? {

        Some(c) => call(&c, "GET", "/api/v1/agents", None).await?.as_array().cloned().unwrap_or_default(),

        None => list_local(ctx).await?,

    };

    print_list(out, json)

}

async fn list_local(ctx: &Ctx) -> Result<Vec<serde_json::Value>> {

    let ledger = Ledger::open_read_only(&ctx.db()?).await?;

    let p = Principals::load(&ledger).await?;

    let rows: Vec<AgentRow> = sqlx::query_as(

        "SELECT a.name, a.key, a.kind, a.project, a.disabled_ms, p.state AS presence, p.status_text AS status FROM agents a LEFT JOIN presence p ON p.agent = a.name ORDER BY a.name",

    )

    .fetch_all(ledger.pool())

    .await?;

    let owner = p.owner();

    let now = now_ms();

    let mut out = Vec::new();

    for AgentRow { name, key, kind, project, disabled_ms: disabled, presence, status } in rows {

        let k = spectra_core::identity::KeyId::from_hex(&key).context("a stored key")?;

        let state = match p.principal(&k, now) {

            Ok(_) => "ok".to_string(),

            Err(why) => why,

        };

        let expires = owner.and_then(|o| o.delegate(&k)).and_then(|d| d.expires);

        let who = match p.principal(&k, now) {

            Ok(pr @ Principal::Agent { .. }) => pr.display(),

            _ => format!("{name} · {}'s agent", owner.map(|o| o.name.as_str()).unwrap_or("?")),

        };

        let presence = if disabled.is_some() { "offline".to_string() } else { presence.unwrap_or_else(|| "offline".into()) };

        out.push(serde_json::json!({ "name": name, "display": who, "key": key, "kind": kind, "project": project, "state": state, "presence": presence, "status": status, "delegation_expires": expires, "disabled": disabled.is_some() }));

    }

    Ok(out)

}

fn print_list(out: Vec<serde_json::Value>, json: bool) -> Result<i32> {

    if json {

        println!("{}", serde_json::Value::Array(out));

        return Ok(0);

    }

    if out.is_empty() {

        println!("{} {}", ui::note(), ui::dim("no agents yet: spectra agent add NAME --kind KIND --project PROJECT --home DIR"));

    }

    for a in out {

        let state = a["state"].as_str().unwrap_or("");

        let until = a["delegation_expires"].as_u64().map(|e| format!("{}until {}", ui::sep(), super::format::when(e))).unwrap_or_default();

        let display = a["display"].as_str().unwrap_or("");

        let (name, owner) = display.split_once(" · ").unwrap_or((display, ""));

        println!(

            "{} {} {}{}{}",

            marks::health(state),

            marks::presence(a["presence"].as_str().unwrap_or("offline")),

            ui::subject(name),

            ui::sep(),

            ui::author(owner)

        );

        if let Some(st) = a["status"].as_str() {

            println!("  {} {}", ui::note(), st);

        }

        println!(

            "  {}",

            ui::dim(format!(

                "{}{}{}{}{}{until}",

                a["kind"].as_str().unwrap_or(""),

                ui::sep(),

                a["project"].as_str().unwrap_or(""),

                ui::sep(),

                &a["key"].as_str().unwrap_or("")[..12]

            ))

        );

        if state != "ok" {

            println!("  {} {}", ui::caution(), ui::warn(state));

        }

    }

    Ok(0)

}

pub async fn disable(ctx: &Ctx, name: &str, owner_home_flag: Option<PathBuf>) -> Result<i32> {

    let home = owner_home(ctx, owner_home_flag);

    let w = ctx.owner_writer(&home).await?;

    let known = match (w.ledger(), w.client()) {

        (_, Some(c)) => call(c, "GET", "/api/v1/agents", None).await?.as_array().is_some_and(|l| l.iter().any(|x| x["name"] == name)),

        (Some(l), None) => Principals::load(l).await?.agent_key(name).is_some(),

        (None, None) => false,

    };

    if !known {

        bail!("no agent named {name}");

    }

    // Stop delegating to its key too, where the owner's identity names it.

    if let Some(key) = agent_key(&w, name).await? {

        if home_identity(&home)?.delegate(&key).is_some() {

            spectra_core::keys::undelegate(&home, key)?;

        }

    }

    let mut events: Vec<_> = w.refresh_event(&home).await?.into_iter().collect();

    let owner = KeyPair::load_home(&home)?;

    events.push(signed_event(&owner, "human", "agent.disabled", serde_json::json!({ "name": name })));

    w.append(events).await?;

    println!("{} {}", ui::done("Disabled"), ui::subject(name));

    println!("  {} {}", ui::note(), ui::dim("its key is refused from now on; earlier events keep their signatures"));

    Ok(0)

}

/// An agent's key by name, from the daemon or the ledger here.

async fn agent_key(w: &super::Writer, name: &str) -> Result<Option<spectra_core::identity::KeyId>> {

    Ok(match (w.client(), w.ledger()) {

        (Some(c), _) => call(c, "GET", "/api/v1/agents", None).await?.as_array().and_then(|l| {

            l.iter().find(|x| x["name"] == name).and_then(|x| x["key"].as_str().and_then(spectra_core::identity::KeyId::from_hex))

        }),

        (None, Some(l)) => Principals::load(l).await?.agent_key(name),

        (None, None) => None,

    })

}

/// `spectra agent renew NAME --expires 8h`: the owner's successor with a

/// new expiry for the agent's key, recorded.

pub async fn renew(ctx: &Ctx, name: &str, expires: &str, owner_home_flag: Option<PathBuf>) -> Result<i32> {

    let home = owner_home(ctx, owner_home_flag);

    let w = ctx.owner_writer(&home).await?;

    let key = agent_key(&w, name).await?.with_context(|| format!("no agent named {name}"))?;

    let expires = expiry(expires)?;

    spectra_core::keys::delegate(&home, key, expires)?;

    let events: Vec<_> = w.refresh_event(&home).await?.into_iter().collect();

    w.append(events).await?;

    let until = expires.map(|e| format!("until {}", super::format::when(e))).unwrap_or_else(|| "until you disable it".into());

    println!("{} {}{}{}", ui::done("Renewed"), ui::subject(name), ui::sep(), until);

    Ok(0)

}

pub fn valid_name(n: &str) -> bool {

    !n.is_empty()

        && n.len() <= 64

        && n.bytes().next().is_some_and(|b| b.is_ascii_lowercase() || b.is_ascii_digit())

        && n.bytes().all(|b| b.is_ascii_lowercase() || b.is_ascii_digit() || b == b'-')

}