//! am roles — the aichat copilot layer (épique v1.1.0, F3).
//!
//! Generates aichat agent definitions that turn `am ai` into a
//! contextual copilot: guide & catalog, secured OS operator, dev helper,
//! raw execution, analyst, orchestrator. Each prompt is bilingual (French
//! by default, English supported) and instructs the model to use the
//! stable `--json` contracts of `am` to inspect the environment.
//!
//! Two layouts are written for compatibility with every aichat version:
//! - aichat >= 0.30 : `functions/agents/<name>/index.yaml` (definition)
//!   + `functions/agents.txt` (registry), under the aichat config dir;
//! - aichat <= 0.29 : legacy markdown agents `agents/<name>.md`.
//!
//! The aichat config file is only created when it does not exist yet —
//! an existing configuration is never touched (respect of the user setup).

use crate::app::App;
use anyhow::Result;
use std::path::{Path, PathBuf};

/// The six copilot roles shipped by `am setup` / `am setup --roles`.
pub const ROLE_NAMES: &[&str] = &[
    "am-copilot",
    "am-operator",
    "am-dev",
    "am-do",
    "am-analyst",
    "am-orchestrator",
];

/// Base config directory of aichat. Candidates are probed in order: an
/// existing aichat config wins, otherwise the platform default (XDG on
/// unix, %APPDATA% on Windows).
pub fn aichat_config_dir() -> PathBuf {
    let mut candidates: Vec<PathBuf> = Vec::new();
    if let Ok(xdg) = std::env::var("XDG_CONFIG_HOME") {
        candidates.push(PathBuf::from(xdg).join("aichat"));
    }
    if let Some(home) = crate::config::home_dir() {
        candidates.push(home.join(".config").join("aichat"));
    }
    if cfg!(windows) {
        if let Ok(appdata) = std::env::var("APPDATA") {
            candidates.push(PathBuf::from(appdata).join("aichat"));
        }
    }
    for c in &candidates {
        if c.exists() {
            return c.clone();
        }
    }
    // No existing aichat config: platform default.
    if cfg!(windows) {
        if let Ok(appdata) = std::env::var("APPDATA") {
            return PathBuf::from(appdata).join("aichat");
        }
    }
    crate::config::home_dir()
        .unwrap_or_else(|| PathBuf::from("."))
        .join(".config")
        .join("aichat")
}

/// Legacy agents directory (aichat <= 0.29): `agents/<name>.md` files
/// with frontmatter. aichat >= 0.30 reads the new definitions instead
/// (see [`aichat_agent_def_dir`]); the .md files are still written so
/// older aichat versions keep working.
pub fn aichat_agents_dir() -> PathBuf {
    aichat_config_dir().join("agents")
}

/// Functions directory (aichat >= 0.30): agent definitions live in
/// `functions/agents/<name>/index.yaml` and the agent registry in
/// `functions/agents.txt`.
pub fn aichat_functions_dir() -> PathBuf {
    aichat_config_dir().join("functions")
}

/// Directory of one agent definition (aichat >= 0.30).
pub fn aichat_agent_def_dir(name: &str) -> PathBuf {
    aichat_functions_dir().join("agents").join(name)
}

/// Path of the aichat configuration file (created only if absent).
pub fn aichat_config_path() -> PathBuf {
    aichat_config_dir().join("config.yaml")
}

/// The list of `am` commands, embedded in the copilot prompt so the model
/// always knows what the CLI can do (kept in sync with `am help commands`).
pub fn command_list() -> String {
    let mut out = String::from(
        "list, status, sessions, stats, top, report, projects, timeline, log, logs, history, ",
    );
    out.push_str(
        "init, alias, secret, open, watch, search, info, install, uninstall, update, start, stop, ",
    );
    out.push_str(
        "restart, run, doctor, config, completion, self-update, self-uninstall, export, import, ",
    );
    out.push_str(
        "shell, theme, lang, tip, dashboard, favorite, unfavorite, note, tag, untag, tags, ",
    );
    out.push_str(
        "profile, man, models, catalog, providers, suggest, ask, ai, registry, audit, service, ",
    );
    out.push_str("schedule, monitor, web, serve, sync, migrate, playbook, lab, plugins, setup");
    out
}

fn frontmatter(name: &str, description: &str, tools: &[&str]) -> String {
    let mut out = String::from("---\n");
    out.push_str(&format!("name: {name}\n"));
    out.push_str(&format!("description: {description}\n"));
    if !tools.is_empty() {
        out.push_str(&format!("tools: [{}]\n", tools.join(", ")));
    }
    out.push_str("---\n");
    out
}

/// The bilingual instruction footer shared by every role.
const LANG_FOOTER: &str = "\n\n## Langue / Language\nRéponds en français par défaut, dans la langue de la demande si une autre est utilisée.\nAnswer in French by default, or in the language of the request when it differs.\n";

/// The (description, tools, body) of one role.
fn role_parts(name: &str) -> Option<(&'static str, &'static [&'static str], String)> {
    let (desc, tools, body) = match name {
        "am-copilot" => (
            "Copilot de agent-manager : guide, catalogue, dépannage",
            &[][..],
            format!(
                "Tu es le copilot de **agent-manager (am)**, le gestionnaire d'agents IA locaux.\n\
                 Tu aides l'utilisateur à exploiter am : catalogue, agents, installation, REPL.\n\
                 \n\
                 Commandes am disponibles : {}\n\
                 \n\
                 Règles :\n\
                 - Privilégie les sorties --json pour inspecter l'environnement : am list --json, am status --json, am info <agent>, am search <mot>.\n\
                 - Pour comprendre l'état : am doctor, am stats --json, am log --kind error.\n\
                 - Propose TOUJOURS la commande exacte à taper, dans un bloc de code.\n\
                 - Si une commande est incertaine, dis-le et propose am help <cmd>.",
                command_list()
            ),
        ),
        "am-operator" => (
            "Opérateur système sécurisé : commandes shell, fichiers, processus",
            &["shell"][..],
            "Tu es un opérateur système SÉCURISÉ. Tu transformes les demandes en commandes shell précises.\n\
             \n\
             Règles de sécurité (non négociables) :\n\
             - N'exécute jamais directement : propose la commande, laisse l'utilisateur ou am ai --exec l'exécuter après confirmation.\n\
             - Signale clairement les commandes RISKY (rm -rf, dd, mkfs, chmod -R 777, git push --force...) et propose une alternative plus sûre quand elle existe.\n\
             - Adapte-toi à l'OS détecté (Windows/cmd/powershell vs Linux/macOS/bash).\n\
             - Pour lister/trier/compresser des fichiers, propose la commande la plus simple possible.".to_string(),
        ),
        "am-dev" => (
            "Assistant développeur : code, git, tests, revue",
            &[][..],
            "Tu es un assistant développeur qui travaille AVEC am (agent-manager).\n\
             \n\
             Tu aides sur :\n\
             - Refactoring, debugging, écriture de tests, revue de code (diff).\n\
             - Git : am ne gère pas git directement — propose les commandes git exactes.\n\
             - Suivi de projets : am projects --json, am timeline --json pour le contexte d'activité.\n\
             - Choix d'agent : am search <tâche> pour recommander un coding agent du catalogue, puis am install / am run.\n\
             \n\
             Réponds avec du code concret et des commandes exactes.".to_string(),
        ),
        "am-do" => (
            "Exécution pure : génère la commande brute pour am ai --exec",
            &["shell"][..],
            "Tu es le moteur d'exécution de am ai --exec.\n\
             \n\
             Réponds UNIQUEMENT par la commande shell exacte à exécuter, sur une seule ligne si possible.\n\
             - Aucune explication avant/après : seulement la commande.\n\
             - Si la demande est dangereuse, réponds par la commande la plus conservatrice qui satisfait la demande.\n\
             - Adapte-toi à l'OS détecté.".to_string(),
        ),
        "am-analyst" => (
            "Analyste : coûts, logs, statistiques, santé du parc d'agents",
            &[][..],
            "Tu es l'analyste de la flotte d'agents gérée par am.\n\
             \n\
             Sources de données (toujours en --json) :\n\
             - Coûts : am stats --costs --json, am top --json\n\
             - Logs & erreurs : am log --kind error --limit 50 --json, am logs <agent> --lines 50\n\
             - Activité : am timeline --json, am sessions --json, am report --period week\n\
             - Santé : am doctor --json, am status --json\n\
             \n\
             Produis des synthèses courtes avec les chiffres clés, et propose des actions concrètes.".to_string(),
        ),
        "am-orchestrator" => (
            "Orchestrateur : groupes, lab, benchmarks, automatisation",
            &[][..],
            "Tu es l'orchestrateur des agents am.\n\
             \n\
             Tu aides à :\n\
             - Lancer des groupes : am start group:dev, am start group:dev --parallel\n\
             - Benchmarker : am lab --agents a,b --task <fichier> --json\n\
             - Automatiser : am schedule add <cmd...>, am service install <agent>, am playbook <fichier>\n\
             - Planifier des runs et interpréter les résultats (am lab --json).\n\
             \n\
             Propose toujours des commandes exactes et des benchmarks comparables.".to_string(),
        ),
        _ => return None,
    };
    Some((desc, tools, body))
}

/// The aichat >= 0.30 agent definition (`index.yaml`): the subset of
/// aichat's AgentDefinition that am generates.
#[derive(serde::Serialize)]
struct AgentDefinition {
    name: String,
    description: String,
    version: String,
    instructions: String,
}

/// Build the legacy markdown content of one role (aichat <= 0.29).
pub fn role_content(name: &str) -> Option<String> {
    let (desc, tools, body) = role_parts(name)?;
    Some(format!(
        "{}{}{}",
        frontmatter(name, desc, tools),
        body,
        LANG_FOOTER
    ))
}

/// The aichat >= 0.30 `index.yaml` definition of one role.
pub fn role_definition(name: &str) -> Option<String> {
    let (desc, _tools, body) = role_parts(name)?;
    let def = AgentDefinition {
        name: name.to_string(),
        description: desc.to_string(),
        version: "1.0.0".to_string(),
        instructions: format!("{body}{LANG_FOOTER}"),
    };
    serde_yaml::to_string(&def).ok()
}

/// Write every am-* role into the aichat agent stores (creates the
/// directories when missing). Two layouts are written so any aichat
/// version works:
/// - aichat >= 0.30 : `functions/agents/<name>/index.yaml` (definition)
///   + `functions/agents.txt` (registry);
/// - aichat <= 0.29 : legacy markdown `agents/<name>.md`.
/// Existing files with the same name are overwritten — they are generated
/// artifacts of am.
pub fn generate_all(_app: &App) -> Result<Vec<PathBuf>> {
    let mut written = Vec::new();

    // New layout (aichat >= 0.30): index.yaml definitions + agents.txt.
    let funcs_dir = aichat_functions_dir();
    let agents_dir = funcs_dir.join("agents");
    std::fs::create_dir_all(&agents_dir)?;
    for name in ROLE_NAMES {
        let def = role_definition(name).expect("known role");
        let def_path = agents_dir.join(name).join("index.yaml");
        std::fs::create_dir_all(def_path.parent().expect("parent dir"))?;
        std::fs::write(&def_path, def)?;
        written.push(def_path);
    }
    let list_path = funcs_dir.join("agents.txt");
    let mut list = String::from("# generated by `am setup` — aichat >= 0.30 agent registry\n");
    list.push_str(&format!("{}\n", ROLE_NAMES.join("\n")));
    std::fs::write(&list_path, list)?;
    written.push(list_path);

    // Legacy layout (aichat <= 0.29): markdown agents in agents/.
    let legacy_dir = aichat_agents_dir();
    std::fs::create_dir_all(&legacy_dir)?;
    for name in ROLE_NAMES {
        let content = role_content(name).expect("known role");
        let path = legacy_dir.join(format!("{name}.md"));
        std::fs::write(&path, content)?;
        written.push(path);
    }
    Ok(written)
}

/// Create the aichat config file (provider + default model) ONLY when it
/// does not exist. An existing configuration is left untouched.
pub fn ensure_config_file(app: &App) -> Result<bool> {
    let path = aichat_config_path();
    if path.exists() {
        return Ok(false);
    }
    let provider = crate::providers::default_name(&app.config);
    let model = provider.and_then(|p| crate::providers::get(&app.config, p))
        .and_then(|def| def.default_model.clone());
    let mut body = String::from("# generated by `am setup` — first run only\n");
    if let Some(p) = provider {
        body.push_str(&format!("model_provider: {p}\n"));
    }
    if let Some(m) = model {
        body.push_str(&format!("model: {m}\n"));
    }
    if let Some(dir) = path.parent() {
        std::fs::create_dir_all(dir)?;
    }
    std::fs::write(&path, body)?;
    Ok(true)
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn generates_all_six_roles_with_frontmatter() {
        for name in ROLE_NAMES {
            let content = role_content(name).expect("role");
            assert!(content.starts_with("---\n"), "{name}");
            assert!(content.contains(&format!("name: {name}")), "{name}");
            assert!(content.contains("description:"), "{name}");
            // Bilingual footer present.
            assert!(content.contains("Réponds en français"), "{name}");
        }
    }

    #[test]
    fn shell_tools_only_on_execution_roles() {
        let operator = role_content("am-operator").unwrap();
        assert!(operator.contains("tools: [shell]"));
        let copilot = role_content("am-copilot").unwrap();
        assert!(!copilot.contains("tools:"), "copilot must not have tools");
    }

    #[test]
    fn unknown_role_returns_none() {
        assert!(role_content("am-inconnu").is_none());
    }

    #[test]
    fn copilot_prompt_embeds_the_command_list() {
        let copilot = role_content("am-copilot").unwrap();
        assert!(copilot.contains("am list --json"));
        assert!(copilot.contains("setup"), "command list must include setup");
    }

    #[test]
    fn role_definition_is_valid_index_yaml() {
        for name in ROLE_NAMES {
            let def = role_definition(name).expect("role");
            assert!(def.starts_with("name:"), "{name}:\n{def}");
            assert!(def.contains("description:"), "{name}");
            assert!(def.contains("instructions:"), "{name}");
            assert!(def.contains("Tu es"), "{name}");
        }
    }

    #[test]
    fn agent_def_dir_targets_functions_layout() {
        let s = aichat_agent_def_dir("am-copilot")
            .to_string_lossy()
            .to_string();
        assert!(s.contains("functions"), "{s}");
        assert!(s.ends_with("am-copilot"), "{s}");
        // The registry lives next to the definitions.
        let registry = aichat_functions_dir().join("agents.txt");
        assert!(registry.to_string_lossy().ends_with("agents.txt"));
    }

    #[test]
    fn agents_dir_prefers_existing_aichat_config() {
        // With a home dir, the unix candidate is ~/.config/aichat/agents.
        let dir = aichat_agents_dir();
        assert!(dir.ends_with("agents"), "{dir:?}");
    }
}