//! [`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 domain::ports::ProfileStore;
use domain::{OrchestratorCommand, Project, ProfileId};

use crate::agent::{
    CreateAgentFromScratch, CreateAgentInput, LaunchAgent, LaunchAgentInput, ListAgents,
    ListAgentsInput, UpdateAgentContext, UpdateAgentContextInput,
};
use crate::error::AppError;
use crate::terminal::{CloseTerminal, CloseTerminalInput, 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;

/// 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>,
    profiles: Arc<dyn ProfileStore>,
    sessions: Arc<TerminalSessions>,
}

/// 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,
}

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>,
        profiles: Arc<dyn ProfileStore>,
        sessions: Arc<TerminalSessions>,
    ) -> Self {
        Self {
            create_agent,
            launch_agent,
            list_agents,
            close_terminal,
            update_context,
            profiles,
            sessions,
        }
    }

    /// 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,
            } => self.spawn_agent(project, name, profile, context).await,
            OrchestratorCommand::StopAgent { name } => self.stop_agent(project, name).await,
            OrchestratorCommand::UpdateAgentContext { name, context } => {
                self.update_agent_context(project, name, context).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: String,
        context: Option<String>,
    ) -> 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_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
            }
        };

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

        Ok(OrchestratorOutcome {
            detail: format!("launched agent {name}"),
        })
    }

    /// `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}"),
        })
    }

    /// `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}"),
        })
    }

    /// 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}",
        )
        .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());
    }
}