//! [`OrchestratorService`] — dispatches a validated [`OrchestratorCommand`] to the
//! existing agent/terminal use cases (ARCHITECTURE §14.3).
//!
//! The orchestrator agent never spawns a process itself: IdeA is the single source
//! of truth for the agent lifecycle. This service is the application-layer seam
//! that turns a request into the *same* calls the UI makes:
//!
//! - `spawn_agent`     → [`CreateAgentFromScratch`] (if unknown) then [`LaunchAgent`],
//! - `stop_agent`      → resolve the agent's live session, then [`CloseTerminal`],
//! - `update_agent_context` → [`UpdateAgentContext`].
//!
//! It talks **only** to use cases and ports ([`ProfileStore`], [`TerminalSessions`]):
//! no filesystem watching, no JSON, no process spawning here — those are the
//! infrastructure adapter's job. That keeps this fully unit-testable with fakes.

use std::sync::Arc;
use std::time::Duration;

use domain::ports::{EventBus, ProfileStore};
use domain::{DomainEvent, OrchestratorCommand, OrchestratorVisibility, ProfileId, Project};

use crate::agent::{
    send_blocking, CreateAgentFromScratch, CreateAgentInput, LaunchAgent, LaunchAgentInput,
    ListAgents, ListAgentsInput, UpdateAgentContext, UpdateAgentContextInput,
};
use crate::error::AppError;
use crate::skill::{CreateSkill, CreateSkillInput};
use crate::terminal::{CloseTerminal, CloseTerminalInput, StructuredSessions, TerminalSessions};

/// Default terminal geometry for an orchestrator-launched agent cell. The UI
/// resizes the PTY to the real cell size on attach; these are sane starting rows
/// /cols so the spawn never fails on a zero-sized terminal.
const DEFAULT_ROWS: u16 = 24;
/// See [`DEFAULT_ROWS`].
const DEFAULT_COLS: u16 = 80;

/// Bound on the synchronous inter-agent rendezvous (`agent.message` → `AskAgent`).
///
/// A target agent's turn can be long (reasoning + tool use), so the cap is
/// generous; on expiry [`send_blocking`] returns [`domain::ports::AgentSessionError::Timeout`]
/// **without killing the session**, so the requester can retry. Internal and
/// intentionally not yet config-exposed (it may become a per-project setting
/// without changing the contract).
const ASK_AGENT_TIMEOUT: Duration = Duration::from_secs(300);

/// Dispatches validated orchestrator commands to the agent/terminal use cases.
pub struct OrchestratorService {
    create_agent: Arc<CreateAgentFromScratch>,
    launch_agent: Arc<LaunchAgent>,
    list_agents: Arc<ListAgents>,
    close_terminal: Arc<CloseTerminal>,
    update_context: Arc<UpdateAgentContext>,
    create_skill: Arc<CreateSkill>,
    profiles: Arc<dyn ProfileStore>,
    sessions: Arc<TerminalSessions>,
    /// Registre des sessions **structurées** (§17.5) — la cible d'un `agent.message`
    /// y est cherchée pour le rendez-vous synchrone. Injecté au câblage via
    /// [`Self::with_structured`] ; `None` ⇒ `AskAgent` ne peut pas être servi (les
    /// call sites/tests legacy qui n'utilisent pas la messagerie restent verts).
    structured: Option<Arc<StructuredSessions>>,
    /// Bus d'événements pour publier [`DomainEvent::AgentReplied`] à l'issue d'un
    /// `ask` réussi (§17.4). Injecté via [`Self::with_events`] ; `None` ⇒ pas de
    /// publication (l'`ask` fonctionne quand même).
    events: Option<Arc<dyn EventBus>>,
}

/// Outcome of dispatching a command — a short, human-readable success summary the
/// infrastructure adapter folds into the JSON response file.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct OrchestratorOutcome {
    /// One-line description of what IdeA did (e.g. `"launched agent dev-backend"`).
    pub detail: String,
    /// The target agent's **reply content** for a synchronous `agent.message`
    /// (`AskAgent`, §17.4). `Some(content)` carries the turn's `Final`; every other
    /// command leaves it `None`. Additive field ⇒ existing call sites/tests are
    /// untouched (they only read [`Self::detail`]).
    pub reply: Option<String>,
}

impl OrchestratorService {
    /// Builds the service from the use cases and ports it dispatches to.
    #[must_use]
    #[allow(clippy::too_many_arguments)]
    pub fn new(
        create_agent: Arc<CreateAgentFromScratch>,
        launch_agent: Arc<LaunchAgent>,
        list_agents: Arc<ListAgents>,
        close_terminal: Arc<CloseTerminal>,
        update_context: Arc<UpdateAgentContext>,
        create_skill: Arc<CreateSkill>,
        profiles: Arc<dyn ProfileStore>,
        sessions: Arc<TerminalSessions>,
    ) -> Self {
        Self {
            create_agent,
            launch_agent,
            list_agents,
            close_terminal,
            update_context,
            create_skill,
            profiles,
            sessions,
            structured: None,
            events: None,
        }
    }

    /// Branche le registre des sessions **structurées** (§17.5) pour servir
    /// `agent.message`/[`OrchestratorCommand::AskAgent`]. Builder additif façon D3 :
    /// signature de [`Self::new`] **inchangée** (les tests/call sites legacy restent
    /// verts), le câblage fait `OrchestratorService::new(...).with_structured(reg)`.
    #[must_use]
    pub fn with_structured(mut self, structured: Arc<StructuredSessions>) -> Self {
        self.structured = Some(structured);
        self
    }

    /// Branche l'[`EventBus`] pour publier [`DomainEvent::AgentReplied`] après un
    /// `ask` réussi (§17.4). Builder additif (cf. [`Self::with_structured`]).
    #[must_use]
    pub fn with_events(mut self, events: Arc<dyn EventBus>) -> Self {
        self.events = Some(events);
        self
    }

    /// Dispatches a validated command against `project`.
    ///
    /// # Errors
    /// Propagates the underlying use-case [`AppError`] (e.g. unknown profile,
    /// unknown agent, PTY failure). For `spawn_agent` a *known* agent is launched
    /// directly; an *unknown* one is created from scratch first.
    pub async fn dispatch(
        &self,
        project: &Project,
        command: OrchestratorCommand,
    ) -> Result<OrchestratorOutcome, AppError> {
        match command {
            OrchestratorCommand::SpawnAgent {
                name,
                profile,
                context,
                visibility,
            } => {
                self.spawn_agent(project, name, profile, context, visibility)
                    .await
            }
            OrchestratorCommand::AskAgent { target, task } => {
                self.ask_agent(project, target, task).await
            }
            OrchestratorCommand::StopAgent { name } => self.stop_agent(project, name).await,
            OrchestratorCommand::UpdateAgentContext { name, context } => {
                self.update_agent_context(project, name, context).await
            }
            OrchestratorCommand::CreateSkill {
                name,
                content,
                scope,
            } => self.create_skill(project, name, content, scope).await,
        }
    }

    /// `spawn_agent`: create the agent if the manifest doesn't already hold one by
    /// that name, then launch it (which publishes `AgentLaunched` → the UI opens a
    /// cell + the Agents tab).
    async fn spawn_agent(
        &self,
        project: &Project,
        name: String,
        profile: Option<String>,
        context: Option<String>,
        visibility: OrchestratorVisibility,
    ) -> Result<OrchestratorOutcome, AppError> {
        let existing = self.find_agent_id_by_name(project, &name).await?;

        let agent_id = match existing {
            Some(id) => id,
            None => {
                let profile = profile.as_deref().ok_or_else(|| {
                    AppError::Invalid("profile is required to create an agent".to_owned())
                })?;
                let profile_id = self.resolve_profile(profile).await?;
                let created = self
                    .create_agent
                    .execute(CreateAgentInput {
                        project: project.clone(),
                        name: name.clone(),
                        profile_id,
                        initial_content: context,
                    })
                    .await?;
                created.agent.id
            }
        };

        if let Some(session_id) = self.sessions.session_for_agent(&agent_id) {
            match visibility {
                OrchestratorVisibility::Background => {
                    return Ok(OrchestratorOutcome {
                        detail: format!("agent {name} already running in background"),
                        reply: None,
                    });
                }
                OrchestratorVisibility::Visible { node_id } => {
                    let session = self
                        .sessions
                        .rebind_agent_node(&agent_id, node_id)
                        .ok_or_else(|| {
                            AppError::NotFound(format!(
                                "running session {session_id} for agent {name}"
                            ))
                        })?;
                    return Ok(OrchestratorOutcome {
                        detail: format!("attached agent {name} to cell {}", session.node_id),
                        reply: None,
                    });
                }
            }
        }

        let node_id = match visibility {
            OrchestratorVisibility::Background => None,
            OrchestratorVisibility::Visible { node_id } => Some(node_id),
        };

        self.launch_agent
            .execute(LaunchAgentInput {
                project: project.clone(),
                agent_id,
                rows: DEFAULT_ROWS,
                cols: DEFAULT_COLS,
                node_id,
                conversation_id: None,
            })
            .await?;

        Ok(OrchestratorOutcome {
            detail: match visibility {
                OrchestratorVisibility::Background => {
                    format!("launched agent {name} in background")
                }
                OrchestratorVisibility::Visible { node_id } => {
                    format!("launched agent {name} in cell {node_id}")
                }
            },
            reply: None,
        })
    }

    /// `agent.message`: the **synchronous inter-agent rendezvous** (§17.4).
    ///
    /// Resolves the target by name, ensures it has a **live structured session**
    /// (launching it in structured mode if needed), sends `task` and **waits for the
    /// turn's `Final`** via [`send_blocking`], then returns its content as
    /// [`OrchestratorOutcome::reply`] and publishes [`DomainEvent::AgentReplied`].
    ///
    /// Invariants:
    /// - **1 session vivante/agent** : on réutilise la session structurée vivante si
    ///   elle existe ; sinon `LaunchAgent` (gardé sur les deux registres) la crée.
    /// - **Timeout ne tue pas la session** : [`send_blocking`] remonte
    ///   [`AppError::Process`] (via [`domain::ports::AgentSessionError::Timeout`]) en
    ///   laissant la session vivante dans le registre (retry possible).
    /// - **Cible PTY-only** (profil sans `structured_adapter`, ou agent déjà vivant en
    ///   PTY) ⇒ [`AppError::Invalid`] explicite, **jamais** un ACK trompeur.
    ///
    /// # Errors
    /// - [`AppError::NotFound`] si l'agent cible est inconnu ;
    /// - [`AppError::Invalid`] si la messagerie structurée n'est pas câblée, ou si la
    ///   cible n'est pas pilotable en mode structuré ;
    /// - [`AppError::Process`] sur échec/timeout du tour structuré.
    async fn ask_agent(
        &self,
        project: &Project,
        target: String,
        task: String,
    ) -> Result<OrchestratorOutcome, AppError> {
        let structured = self.structured.as_ref().ok_or_else(|| {
            AppError::Invalid(
                "la messagerie inter-agents (agent.message) n'est pas disponible : \
                 registre des sessions structurées non câblé"
                    .to_owned(),
            )
        })?;

        let agent_id = self
            .find_agent_id_by_name(project, &target)
            .await?
            .ok_or_else(|| AppError::NotFound(format!("agent {target}")))?;

        // 1. Session structurée déjà vivante ? ⇒ rendez-vous direct.
        if let Some(session) = structured.session_for_agent(&agent_id) {
            let content = send_blocking(session.as_ref(), &task, Some(ASK_AGENT_TIMEOUT)).await?;
            return Ok(self.reply_outcome(agent_id, &target, content));
        }

        // 2. Pas de session structurée. Si l'agent est vivant en **PTY** (terminal
        //    brut), il n'est pas adressable en `ask` ⇒ erreur typée explicite (pas
        //    d'ACK « launched »).
        if self.sessions.session_for_agent(&agent_id).is_some() {
            return Err(AppError::Invalid(format!(
                "agent {target} n'est pas pilotable en mode structuré \
                 (session terminal brut, pas de canal de réponse)"
            )));
        }

        // 3. Cible morte : on la lance en mode structuré (background) puis on envoie.
        let launched = self
            .launch_agent
            .execute(LaunchAgentInput {
                project: project.clone(),
                agent_id,
                rows: DEFAULT_ROWS,
                cols: DEFAULT_COLS,
                node_id: None,
                conversation_id: None,
            })
            .await?;

        // Si le lancement n'a pas produit de session structurée, le profil de la cible
        // est PTY-only (pas de `structured_adapter`) ⇒ non adressable en `ask`.
        if launched.structured.is_none() {
            return Err(AppError::Invalid(format!(
                "agent {target} n'est pas pilotable en mode structuré \
                 (profil sans adaptateur structuré)"
            )));
        }

        // La session vient d'être enregistrée par LaunchAgent : on la récupère par
        // agent (invariant « 1 session/agent » ⇒ non ambigu).
        let session = structured.session_for_agent(&agent_id).ok_or_else(|| {
            AppError::Process(format!(
                "session structurée de l'agent {target} introuvable après lancement"
            ))
        })?;
        let content = send_blocking(session.as_ref(), &task, Some(ASK_AGENT_TIMEOUT)).await?;
        Ok(self.reply_outcome(agent_id, &target, content))
    }

    /// Builds the success outcome of an `ask` and publishes [`DomainEvent::AgentReplied`]
    /// (best-effort: a missing event bus never fails the rendezvous).
    fn reply_outcome(
        &self,
        agent_id: domain::AgentId,
        target: &str,
        content: String,
    ) -> OrchestratorOutcome {
        if let Some(events) = &self.events {
            events.publish(DomainEvent::AgentReplied {
                agent_id,
                reply_len: content.len(),
            });
        }
        OrchestratorOutcome {
            detail: format!("agent {target} replied ({} bytes)", content.len()),
            reply: Some(content),
        }
    }

    /// `stop_agent`: translate the agent name → its live session → `CloseTerminal`.
    async fn stop_agent(
        &self,
        project: &Project,
        name: String,
    ) -> Result<OrchestratorOutcome, AppError> {
        let agent_id = self
            .find_agent_id_by_name(project, &name)
            .await?
            .ok_or_else(|| AppError::NotFound(format!("agent {name}")))?;

        let session_id = self
            .sessions
            .session_for_agent(&agent_id)
            .ok_or_else(|| AppError::NotFound(format!("running session for agent {name}")))?;

        self.close_terminal
            .execute(CloseTerminalInput { session_id })
            .await?;

        Ok(OrchestratorOutcome {
            detail: format!("stopped agent {name}"),
            reply: None,
        })
    }

    /// `update_agent_context`: overwrite the agent's `.md` body.
    async fn update_agent_context(
        &self,
        project: &Project,
        name: String,
        context: String,
    ) -> Result<OrchestratorOutcome, AppError> {
        let agent_id = self
            .find_agent_id_by_name(project, &name)
            .await?
            .ok_or_else(|| AppError::NotFound(format!("agent {name}")))?;

        self.update_context
            .execute(UpdateAgentContextInput {
                project: project.clone(),
                agent_id,
                content: context,
            })
            .await?;

        Ok(OrchestratorOutcome {
            detail: format!("updated context for agent {name}"),
            reply: None,
        })
    }

    /// `create_skill`: create a reusable skill in the requested scope — the same
    /// path the UI's "New skill" action takes. For [`SkillScope::Project`] the
    /// skill lands under `<root>/.ideai/skills/`; for [`SkillScope::Global`] the
    /// project root is ignored by the store.
    async fn create_skill(
        &self,
        project: &Project,
        name: String,
        content: String,
        scope: domain::SkillScope,
    ) -> Result<OrchestratorOutcome, AppError> {
        let created = self
            .create_skill
            .execute(CreateSkillInput {
                name: name.clone(),
                content,
                scope,
                project_root: project.root.clone(),
            })
            .await?;

        Ok(OrchestratorOutcome {
            detail: format!("created skill {} ({:?})", created.skill.name, scope),
            reply: None,
        })
    }

    /// Finds an agent id by display name (case-insensitive) in the project manifest.
    async fn find_agent_id_by_name(
        &self,
        project: &Project,
        name: &str,
    ) -> Result<Option<domain::AgentId>, AppError> {
        let listed = self
            .list_agents
            .execute(ListAgentsInput {
                project: project.clone(),
            })
            .await?;
        Ok(listed
            .agents
            .into_iter()
            .find(|a| a.name.eq_ignore_ascii_case(name))
            .map(|a| a.id))
    }

    /// Resolves a human-friendly profile reference (slug like `claude-code`,
    /// command like `claude`, or display name like `Claude Code`) to a configured
    /// [`ProfileId`]. Matching is universal — never hard-coded to one AI — by
    /// scanning the configured profiles' command and name.
    ///
    /// # Errors
    /// [`AppError::NotFound`] when no configured profile matches.
    async fn resolve_profile(&self, reference: &str) -> Result<ProfileId, AppError> {
        let needle = normalise(reference);
        let profiles = self.profiles.list().await?;
        profiles
            .into_iter()
            .find(|p| {
                normalise(&p.command) == needle
                    || normalise(&p.name) == needle
                    || p.id.to_string() == reference
            })
            .map(|p| p.id)
            .ok_or_else(|| AppError::NotFound(format!("profile matching '{reference}'")))
    }
}

/// Normalises a profile reference for tolerant matching: lowercased, with spaces,
/// dashes and underscores stripped (`"Claude Code"`, `"claude-code"`, `"claude"`
/// → comparable forms; `claude` ⊂ ... handled by the command match above).
fn normalise(s: &str) -> String {
    s.chars()
        .filter(|c| c.is_ascii_alphanumeric())
        .map(|c| c.to_ascii_lowercase())
        .collect()
}

#[cfg(test)]
mod tests {
    use super::*;
    use domain::profile::{AgentProfile, ContextInjection};
    use domain::ProfileId;

    fn profile(id: u128, name: &str, command: &str) -> AgentProfile {
        AgentProfile::new(
            ProfileId::from_uuid(uuid::Uuid::from_u128(id)),
            name,
            command,
            Vec::new(),
            ContextInjection::convention_file("CLAUDE.md").unwrap(),
            None,
            "{agentRunDir}",
            None,
        )
        .unwrap()
    }

    #[test]
    fn normalise_makes_slug_command_and_name_comparable() {
        assert_eq!(normalise("Claude Code"), "claudecode");
        assert_eq!(normalise("claude-code"), "claudecode");
        assert_eq!(normalise("claude_code"), "claudecode");
    }

    #[test]
    fn resolve_matches_by_command_name_or_id() {
        // We exercise the pure matching predicate the same way `resolve_profile`
        // does, without standing up the whole service/ports.
        let p = profile(1, "Claude Code", "claude");
        let by_command = normalise("claude") == normalise(&p.command);
        let by_name = normalise("claude-code") == normalise(&p.name);
        assert!(by_command);
        assert!(by_name);
        assert_eq!(p.id.to_string(), p.id.to_string());
    }
}