rpi-cli 0.1.18

//! Resource-directory resolution + **project-wins dedupe** for skills and
//! prompt templates. Mirrors the precedence contract from pi's
//! `DefaultResourceLoader`/`package-manager` (`resource-loader.ts:676-681`,
//! `package-manager.ts:178-181`): resources are ranked project=0/1 < user=2/3
//! < package=4, and `addSkills`/`dedupePrompts` are **first-registration-wins**
//! on name → loading project *before* global means **project wins** on
//! collision (skills.ts:399-428), with a collision diagnostic naming the winner
//! (kept) and loser (dropped) paths.
//!
//! rpi's library loaders (`rpi_harness::skills::load_skills`,
//! `rpi_harness::prompt_templates::load_prompt_templates`) are **append-only**
//! (no dedup-by-name) — they correctly mirror pi's *per-directory* discovery
//! (SKILL.md-first / root-.md / subdir recursion for skills; non-recursive `.md`
//! children for prompts) but leave the cross-directory merge to the caller. This
//! module is that caller-side merge: load project dir then global dir, then
//! dedupe first-wins-by-name so project wins.
//!
//! **Trust gate (v1 divergence):** pi gates project `SYSTEM.md` /
//! `APPEND_SYSTEM.md` (and some project resources) behind
//! `settingsManager.isProjectTrusted()`. rpi v1 has **no trust prompt**
//! (`config.rs:349`: "does not gate any project resources behind trust in v1"),
//! so project resources are read unconditionally here. A copied `.rpi/` or
//! `.pi/` directory drops in and works (the documented intent). Full trust
//! gating is deferred.
//!
//! **Deferred (documented):** pi's `.agents/skills` + `~/.agents/skills` (rpi
//! package-installed static resources are handled by `crate::packages`); worktree
//! shadowed-context-file dedup (`findShadowedContextFile`); full structured
//! winner/loser collision diagnostics (rpi v1 encodes collisions as a
//! `SkillDiagnostic`/`PromptTemplateDiagnostic` with a descriptive message).

use std::collections::HashMap;
use std::path::{Path, PathBuf};
use std::sync::Arc;

use rpi_harness::prompt_templates::{
    load_prompt_templates, LoadPromptTemplatesResult, PromptTemplateDiagnostic,
    PromptTemplateDiagnosticCode,
};
use rpi_harness::skills::{load_skills, LoadSkillsResult, SkillDiagnostic, SkillDiagnosticCode};
use rpi_harness::types::{PromptTemplate, Skill};
use rpi_tools::env::ExecutionEnv;

/// The preferred project-local config dir. rpi-owned resources live under
/// `<cwd>/.rpi`; the legacy `.pi` directory remains a compatibility fallback.
pub const PROJECT_CONFIG_DIR_NAME: &str = ".rpi";
/// The upstream Pi project-local config dir, loaded after `.rpi`.
pub const LEGACY_PROJECT_CONFIG_DIR_NAME: &str = ".pi";

/// Resolve the preferred project-local resource subdir `<cwd>/.rpi/<sub>`.
pub fn project_dir(cwd: &Path, sub: &str) -> PathBuf {
    cwd.join(PROJECT_CONFIG_DIR_NAME).join(sub)
}

/// Resolve project-local resource dirs in precedence order: `.rpi` first,
/// then the original Pi `.pi` layout for compatibility.
pub fn project_dirs(cwd: &Path, sub: &str) -> Vec<PathBuf> {
    vec![
        project_dir(cwd, sub),
        cwd.join(LEGACY_PROJECT_CONFIG_DIR_NAME).join(sub),
    ]
}

/// Resolve the global resource subdir `<agent_dir>/<sub>` (e.g.
/// `~/.rpi/agent/skills`). Returns `None` if the agent dir can't be resolved
/// (no home dir + no `RPI_CODING_AGENT_DIR`) — callers then proceed project-only.
pub fn global_dir(sub: &str) -> Option<PathBuf> {
    crate::config::agent_dir().ok().map(|d| d.join(sub))
}

/// The candidate context/SYSTEM/APPEND filenames live directly under
/// `<cwd>/.rpi/`, `<cwd>/.pi/`, and `<agent_dir>/` (no `skills`/`prompts`
/// subdir). Re-exports the
/// harness context-file candidates for the system/append discovery path so
/// callers share one source of truth.
pub fn project_config_file(cwd: &Path, name: &str) -> PathBuf {
    cwd.join(PROJECT_CONFIG_DIR_NAME).join(name)
}

/// Resolve project config files in precedence order: preferred `.rpi`, then
/// legacy `.pi`.
pub fn project_config_files(cwd: &Path, name: &str) -> Vec<PathBuf> {
    vec![
        project_config_file(cwd, name),
        cwd.join(LEGACY_PROJECT_CONFIG_DIR_NAME).join(name),
    ]
}

/// Global config file under `<agent_dir>/<name>` (`~/.rpi/agent/SYSTEM.md`).
pub fn global_config_file(name: &str) -> Option<PathBuf> {
    crate::config::agent_dir().ok().map(|d| d.join(name))
}

// ---------------------------------------------------------------------------
// SYSTEM.md / APPEND_SYSTEM.md discovery (project-wins, mirroring pi)
// ---------------------------------------------------------------------------

/// Discover `SYSTEM.md`: project `<cwd>/.rpi/SYSTEM.md` overrides the legacy
/// `<cwd>/.pi/SYSTEM.md`, and both override global `<agent_dir>/SYSTEM.md`
/// (mirrors pi `discoverSystemPromptFile`
/// `resource-loader.ts:1022-1034`). Returns the first existing file in that
/// order, or `None`.
///
/// This convenience entry point intentionally excludes Pi package resources.
/// Startup code that has passed the package gate supplies its resolved resource
/// set to [`discover_system_prompt_file_with_packages`].
///
/// **Trust gate (v1 divergence):** pi gates the **project** `SYSTEM.md` behind
/// `settingsManager.isProjectTrusted()` (global is always honored). rpi v1 has
/// no trust prompt (`config.rs:349`), so project files are read unconditionally
/// — a copied `.rpi/` or `.pi/` drops in and works. Full trust gating is deferred.
pub fn discover_system_prompt_file(cwd: &Path) -> Option<PathBuf> {
    discover_system_prompt_file_with_packages(cwd, &crate::packages::PackageResources::default())
}

/// Discover `SYSTEM.md` with already-resolved package resources. Package files
/// are considered after project and global files, so installing a package
/// cannot unexpectedly override a user's project instructions.
pub fn discover_system_prompt_file_with_packages(
    cwd: &Path,
    packages: &crate::packages::PackageResources,
) -> Option<PathBuf> {
    for project in project_config_files(cwd, "SYSTEM.md") {
        if project.is_file() {
            return Some(project);
        }
    }
    if let Some(global) = global_config_file("SYSTEM.md").filter(|p| p.is_file()) {
        return Some(global);
    }
    packages
        .system_prompt_files()
        .into_iter()
        .find(|path| path.is_file())
}

/// Discover `APPEND_SYSTEM.md`: same precedence as `SYSTEM.md` — project
/// `<cwd>/.rpi/APPEND_SYSTEM.md` overrides `<cwd>/.pi/APPEND_SYSTEM.md`, and
/// both override global `<agent_dir>/APPEND_SYSTEM.md`
/// (mirrors pi `discoverAppendSystemPromptFile` `resource-loader.ts:1036-1048`).
/// Returns the first existing file in that order, or `None`. The discovered
/// content is appended to the system prompt (pi `appendSystemPrompt`
/// `:525-542`).
///
/// This convenience entry point intentionally excludes Pi package resources.
/// Startup code that has passed the package gate supplies its resolved resource
/// set to [`discover_append_system_prompt_file_with_packages`].
///
/// **Trust gate (v1 divergence):** same as [`discover_system_prompt_file`] —
/// pi gates the project file on trust, rpi v1 reads it unconditionally.
pub fn discover_append_system_prompt_file(cwd: &Path) -> Option<PathBuf> {
    discover_append_system_prompt_file_with_packages(
        cwd,
        &crate::packages::PackageResources::default(),
    )
}

/// Discover `APPEND_SYSTEM.md` with already-resolved package resources.
pub fn discover_append_system_prompt_file_with_packages(
    cwd: &Path,
    packages: &crate::packages::PackageResources,
) -> Option<PathBuf> {
    for project in project_config_files(cwd, "APPEND_SYSTEM.md") {
        if project.is_file() {
            return Some(project);
        }
    }
    if let Some(global) = global_config_file("APPEND_SYSTEM.md").filter(|p| p.is_file()) {
        return Some(global);
    }
    packages
        .append_system_prompt_files()
        .into_iter()
        .find(|path| path.is_file())
}

// ---------------------------------------------------------------------------
// Dedupe: first-wins-by-name (project wins when loaded project→global)
// ---------------------------------------------------------------------------

/// Dedupe skills by name, **first-wins**. Mirrors pi `addSkills`
/// (`skills.ts:399-428`): the first skill with a given name is kept; later
/// duplicates emit a collision diagnostic naming the winner (kept) and loser
/// (dropped) paths. Load dirs in **project→global** order so project wins.
///
/// **v1 divergence:** rpi's `SkillDiagnostic` has no structured
/// `winnerPath`/`loserPath` fields (pi's `SkillCollisionDiagnostic`); the
/// collision is encoded as an `InvalidMetadata` diagnostic with a descriptive
/// message naming both paths and `path` set to the loser.
pub fn dedupe_skills(skills: Vec<Skill>, diagnostics: &mut Vec<SkillDiagnostic>) -> Vec<Skill> {
    let mut winner_path: HashMap<String, String> = HashMap::new();
    let mut out: Vec<Skill> = Vec::with_capacity(skills.len());
    for skill in skills {
        if let Some(winner) = winner_path.get(&skill.name) {
            diagnostics.push(SkillDiagnostic {
                code: SkillDiagnosticCode::InvalidMetadata,
                message: format!(
                    "Skill name \"{}\" from {} is shadowed by {} \
                     (first-registration wins; load project before global so project wins)",
                    skill.name, skill.file_path, winner
                ),
                path: skill.file_path.clone(),
            });
        } else {
            winner_path.insert(skill.name.clone(), skill.file_path.clone());
            out.push(skill);
        }
    }
    out
}

/// Dedupe prompt templates by name, **first-wins**. Mirrors pi `dedupePrompts`
/// (`resource-loader.ts:969-993`): the first template with a given name is kept;
/// later duplicates emit a collision diagnostic. Load paths in **project→global**
/// order so project wins.
///
/// **v1 divergence:** `PromptTemplate` carries no `file_path` (only
/// name/description/content), so the collision diagnostic's `path` is set to the
/// colliding template **name** rather than a file path; and the code is
/// `ParseFailed` (rpi has no dedicated collision code) with a descriptive
/// message. Structured winner/loser diagnostics are deferred.
pub fn dedupe_prompt_templates(
    templates: Vec<PromptTemplate>,
    diagnostics: &mut Vec<PromptTemplateDiagnostic>,
) -> Vec<PromptTemplate> {
    let mut seen: HashMap<String, ()> = HashMap::new();
    let mut out: Vec<PromptTemplate> = Vec::with_capacity(templates.len());
    for t in templates {
        if seen.contains_key(&t.name) {
            diagnostics.push(PromptTemplateDiagnostic {
                code: PromptTemplateDiagnosticCode::ParseFailed,
                message: format!(
                    "Prompt template name \"{}\" is shadowed by an earlier registration \
                     (first-registration wins; load project before global so project wins)",
                    t.name
                ),
                // PromptTemplate carries no file path; the name is the collision
                // key, so use it as the diagnostic path.
                path: t.name.clone(),
            });
        } else {
            seen.insert(t.name.clone(), ());
            out.push(t);
        }
    }
    out
}

// ---------------------------------------------------------------------------
// Precedence-aware loaders: project dir → global dir → dedupe (project wins)
// ---------------------------------------------------------------------------

/// Load skills from `dirs` in order, then dedupe first-wins-by-name. Missing
/// directories are skipped silently by the underlying loader (NotFound →
/// `continue`, mirroring pi). Pass dirs in **project→global** order so project
/// wins on name collisions.
pub async fn load_skills_with_precedence(
    env: &Arc<dyn ExecutionEnv>,
    dirs: &[PathBuf],
) -> LoadSkillsResult {
    let dir_strs: Vec<String> = dirs
        .iter()
        .map(|d| d.to_string_lossy().into_owned())
        .collect();
    let mut result = load_skills(env, &dir_strs).await;
    result.skills = dedupe_skills(result.skills, &mut result.diagnostics);
    result
}

/// Load prompt templates from `paths` (dirs or `.md` files) in order, then
/// dedupe first-wins-by-name. Missing paths are skipped silently. Pass paths in
/// **project→global** order so project wins on name collisions.
pub async fn load_prompt_templates_with_precedence(
    env: &Arc<dyn ExecutionEnv>,
    paths: &[PathBuf],
) -> LoadPromptTemplatesResult {
    let path_strs: Vec<String> = paths
        .iter()
        .map(|p| p.to_string_lossy().into_owned())
        .collect();
    let mut result = load_prompt_templates(env, &path_strs).await;
    result.prompt_templates =
        dedupe_prompt_templates(result.prompt_templates, &mut result.diagnostics);
    result
}

/// The ordered skill dirs for a project: configured project paths, then
/// `[<cwd>/.rpi/skills, <cwd>/.pi/skills, <agent_dir>/skills]`, followed by
/// configured and conventional global paths.
/// The global dir is omitted when `agent_dir()` can't be resolved (no home dir).
pub fn skill_dirs(cwd: &Path) -> Vec<PathBuf> {
    let mut dirs = project_skill_dirs(cwd);
    if let Some(g) = global_dir("skills") {
        dirs.extend(configured_global_dirs(g.clone(), ResourceKind::Skills));
        dirs.push(g);
    }
    dirs
}

/// Project-only skill directories, excluding user/global configuration. This
/// is used by `rpi dev-local` so the current extension can be debugged with
/// the skills in the current checkout without importing unrelated skills.
pub fn project_skill_dirs(cwd: &Path) -> Vec<PathBuf> {
    project_resource_dirs(cwd, "skills", ResourceKind::Skills)
}

/// Resource directories that do not depend on the current project. Used when
/// the project trust gate denies local configuration/resources.
pub fn global_skill_dirs() -> Vec<PathBuf> {
    global_resource_dirs("skills", ResourceKind::Skills)
}

/// The ordered prompt-template paths for a project: configured paths, then
/// `[<cwd>/.rpi/prompts, <cwd>/.pi/prompts, <agent_dir>/prompts]`.
pub fn prompt_template_dirs(cwd: &Path) -> Vec<PathBuf> {
    let mut dirs = project_prompt_template_dirs(cwd);
    if let Some(g) = global_dir("prompts") {
        dirs.extend(configured_global_dirs(g.clone(), ResourceKind::Prompts));
        dirs.push(g);
    }
    dirs
}

/// Project-only prompt-template directories, excluding user/global settings.
pub fn project_prompt_template_dirs(cwd: &Path) -> Vec<PathBuf> {
    project_resource_dirs(cwd, "prompts", ResourceKind::Prompts)
}

pub fn global_prompt_template_dirs() -> Vec<PathBuf> {
    global_resource_dirs("prompts", ResourceKind::Prompts)
}

/// The ordered Rust extension directories for a project. Configured paths are
/// added before conventional directories so an explicit project path can be
/// used for development while `.rpi` remains ahead of legacy `.pi` defaults.
pub fn extension_dirs(cwd: &Path) -> Vec<PathBuf> {
    let mut dirs = project_resource_dirs(cwd, "extensions", ResourceKind::Extensions);
    if let Some(g) = global_dir("extensions") {
        dirs.extend(configured_global_dirs(g.clone(), ResourceKind::Extensions));
        dirs.push(g);
    }
    dirs
}

pub fn global_extension_dirs() -> Vec<PathBuf> {
    global_resource_dirs("extensions", ResourceKind::Extensions)
}

#[derive(Clone, Copy)]
enum ResourceKind {
    Skills,
    Prompts,
    Extensions,
}

fn project_resource_dirs(cwd: &Path, sub: &str, kind: ResourceKind) -> Vec<PathBuf> {
    let loaded = crate::settings::load_project_settings_with_paths(cwd);
    let mut dirs = Vec::new();
    for config_name in [".rpi", ".pi"] {
        if let Some((_, settings)) = loaded.iter().find(|(path, _)| {
            path.parent()
                .and_then(Path::file_name)
                .and_then(|name| name.to_str())
                == Some(config_name)
        }) {
            dirs.extend(configured_paths(settings, cwd, kind));
        }
        dirs.push(cwd.join(config_name).join(sub));
    }
    dirs
}

fn configured_global_dirs(agent_dir: PathBuf, kind: ResourceKind) -> Vec<PathBuf> {
    crate::settings::load_settings()
        .ok()
        .into_iter()
        .flat_map(|settings| configured_paths(&settings, &agent_dir, kind))
        .collect()
}

fn global_resource_dirs(sub: &str, kind: ResourceKind) -> Vec<PathBuf> {
    let Some(g) = global_dir(sub) else {
        return Vec::new();
    };
    let mut dirs = configured_global_dirs(g.clone(), kind);
    dirs.push(g);
    dirs
}

fn configured_paths(
    settings: &crate::settings::Settings,
    base: &Path,
    kind: ResourceKind,
) -> Vec<PathBuf> {
    let values = match kind {
        ResourceKind::Skills => settings.skill_dirs.as_ref(),
        ResourceKind::Prompts => settings.prompt_dirs.as_ref(),
        ResourceKind::Extensions => settings.extension_dirs.as_ref(),
    };
    values
        .map(|paths| crate::settings::resolve_configured_paths(base, paths))
        .unwrap_or_default()
}

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

    fn skill(name: &str, path: &str) -> Skill {
        Skill {
            name: name.to_string(),
            description: "d".to_string(),
            content: "c".to_string(),
            file_path: path.to_string(),
            disable_model_invocation: None,
        }
    }

    fn tmpl(name: &str) -> PromptTemplate {
        PromptTemplate {
            name: name.to_string(),
            description: None,
            content: "c".to_string(),
        }
    }

    #[test]
    fn dedupe_skills_first_wins_keeps_project() {
        // Project loaded first, global second; same name → project (first) wins.
        let skills = vec![
            skill("echo", "/proj/.pi/skills/echo/SKILL.md"),
            skill("echo", "/home/.rpi/agent/skills/echo/SKILL.md"),
        ];
        let mut diags = Vec::new();
        let out = dedupe_skills(skills, &mut diags);
        assert_eq!(out.len(), 1);
        assert_eq!(out[0].file_path, "/proj/.pi/skills/echo/SKILL.md");
        assert_eq!(diags.len(), 1);
        assert!(diags[0]
            .message
            .contains("/home/.rpi/agent/skills/echo/SKILL.md"));
        assert!(diags[0].message.contains("/proj/.pi/skills/echo/SKILL.md"));
        assert_eq!(diags[0].path, "/home/.rpi/agent/skills/echo/SKILL.md");
    }

    #[test]
    fn dedupe_skills_distinct_names_all_kept() {
        let skills = vec![skill("a", "/p/a"), skill("b", "/p/b"), skill("c", "/g/c")];
        let mut diags = Vec::new();
        let out = dedupe_skills(skills, &mut diags);
        assert_eq!(out.len(), 3);
        assert!(diags.is_empty());
    }

    #[test]
    fn dedupe_skills_third_duplicate_drops_against_first() {
        let skills = vec![
            skill("x", "/proj/x"),
            skill("x", "/global/x"),
            skill("x", "/pkg/x"),
        ];
        let mut diags = Vec::new();
        let out = dedupe_skills(skills, &mut diags);
        assert_eq!(out.len(), 1);
        assert_eq!(out[0].file_path, "/proj/x");
        // Both later duplicates emit a collision diagnostic vs the same winner.
        assert_eq!(diags.len(), 2);
    }

    #[test]
    fn dedupe_skills_empty_input() {
        let mut diags = Vec::new();
        let out = dedupe_skills(Vec::new(), &mut diags);
        assert!(out.is_empty());
        assert!(diags.is_empty());
    }

    #[test]
    fn dedupe_prompts_first_wins() {
        let templates = vec![tmpl("greet"), tmpl("greet")];
        let mut diags = Vec::new();
        let out = dedupe_prompt_templates(templates, &mut diags);
        assert_eq!(out.len(), 1);
        assert_eq!(out[0].name, "greet");
        assert_eq!(diags.len(), 1);
        assert_eq!(diags[0].path, "greet");
    }

    #[test]
    fn dedupe_prompts_distinct_all_kept() {
        let templates = vec![tmpl("a"), tmpl("b"), tmpl("c")];
        let mut diags = Vec::new();
        let out = dedupe_prompt_templates(templates, &mut diags);
        assert_eq!(out.len(), 3);
        assert!(diags.is_empty());
    }

    #[test]
    fn project_dir_uses_rpi_name() {
        let d = project_dir(Path::new("/proj"), "skills");
        assert_eq!(d, PathBuf::from("/proj/.rpi/skills"));
    }

    #[test]
    fn project_dirs_keep_pi_compatibility_after_rpi() {
        let dirs = project_dirs(Path::new("/proj"), "extensions");
        assert_eq!(
            dirs,
            vec![
                PathBuf::from("/proj/.rpi/extensions"),
                PathBuf::from("/proj/.pi/extensions")
            ]
        );
    }

    #[test]
    fn project_config_file_prefers_rpi_and_keeps_pi_fallback() {
        let p = project_config_file(Path::new("/proj"), "SYSTEM.md");
        assert_eq!(p, PathBuf::from("/proj/.rpi/SYSTEM.md"));
        assert_eq!(
            project_config_files(Path::new("/proj"), "SYSTEM.md"),
            vec![
                PathBuf::from("/proj/.rpi/SYSTEM.md"),
                PathBuf::from("/proj/.pi/SYSTEM.md")
            ]
        );
    }

    #[test]
    fn project_settings_add_configured_resource_paths() {
        let tmp = tempfile::tempdir().unwrap();
        std::fs::create_dir_all(tmp.path().join(".rpi")).unwrap();
        std::fs::write(
            tmp.path().join(".rpi/settings.json"),
            r#"{"skills":["shared-skills"],"promptDirs":["prompt-pack"],"extensionDirs":["target/debug"]}"#,
        )
        .unwrap();

        let skills = skill_dirs(tmp.path());
        assert_eq!(skills[0], tmp.path().join("shared-skills"));
        assert!(skills.contains(&tmp.path().join(".rpi/skills")));

        let prompts = prompt_template_dirs(tmp.path());
        assert_eq!(prompts[0], tmp.path().join("prompt-pack"));

        let extensions = extension_dirs(tmp.path());
        assert_eq!(extensions[0], tmp.path().join("target/debug"));
        assert!(extensions.contains(&tmp.path().join(".rpi/extensions")));
    }

    #[test]
    fn local_resource_dirs_exclude_global_paths() {
        let tmp = tempfile::tempdir().unwrap();
        std::fs::create_dir_all(tmp.path().join(".rpi")).unwrap();
        std::fs::write(
            tmp.path().join(".rpi/settings.json"),
            r#"{"skills":["local-skills"],"promptDirs":["local-prompts"]}"#,
        )
        .unwrap();

        let skills = project_skill_dirs(tmp.path());
        let prompts = project_prompt_template_dirs(tmp.path());
        assert!(skills.contains(&tmp.path().join("local-skills")));
        assert!(skills.contains(&tmp.path().join(".rpi/skills")));
        assert!(prompts.contains(&tmp.path().join("local-prompts")));
        assert!(prompts.contains(&tmp.path().join(".rpi/prompts")));
    }
}