//! # Built-in Kana Engineering Best Practices Engine
//!
//! This module provides compile-time embedded skills, architecture audit,
//! code-quality scanning, and commit-message validation as **built-in**
//! features of the zesdex binary — not external configuration files.
//!
//! ## Modules
//!
//! | Module | Purpose |
//! |--------|---------|
//! | [`skills`] | Compile-time embedded skill markdown files via `include_dir!` |
//! | [`arch_audit`] | Clean-architecture layering violation scanner |
//! | [`code_quality`] | Clean-code rule checker (unwrap, missing docs, etc.) |
//! | [`commit`] | Conventional Commits message validator |
//!
//! ## Usage
//!
//! The [`BestPracticeEngine`] struct provides a unified API that tools call.
//! New tool implementations in `crate::tools::best_practice` delegate to this
//! engine.

pub mod arch_audit;
pub mod code_quality;
pub mod commit;
pub mod explore;
pub mod skills;

use anyhow::Result;
use std::path::Path;

/// Unified engine for all best-practice operations.
///
/// Wraps the individual audit, quality, and commit modules behind a single
/// struct that tools and subagents can call without knowing the module layout.
#[derive(Default)]
pub struct BestPracticeEngine {
    /// Compile-time embedded skills, lazy-loaded.
    embedded_skills: std::sync::OnceLock<skills::EmbeddedSkills>,
}

impl BestPracticeEngine {
    /// Create a new engine (skills index is built lazily on first access).
    pub fn new() -> Self {
        BestPracticeEngine {
            embedded_skills: std::sync::OnceLock::new(),
        }
    }

    // ── Skills ─────────────────────────────────────────────────────────

    /// Access the embedded skills index.
    pub fn skills(&self) -> &skills::EmbeddedSkills {
        self.embedded_skills
            .get_or_init(skills::EmbeddedSkills::load)
    }

    /// List all available embedded-skills names.
    pub fn list_skills(&self) -> Vec<&'static str> {
        self.skills().list()
    }

    /// Get the full content of a skill by name.
    pub fn get_skill(&self, name: &str) -> Option<&'static str> {
        self.skills().get(name)
    }

    /// Get skill summaries (name + description).
    pub fn skill_summaries(&self) -> Vec<(&'static str, &'static str)> {
        self.skills().summaries()
    }

    // ── Architecture Audit ─────────────────────────────────────────────

    /// Run a full architecture layering audit on a workspace directory.
    pub fn audit_layering(&self, workspace_root: &Path) -> Result<arch_audit::AuditReport> {
        arch_audit::audit_layering(workspace_root)
    }

    // ── Code Quality ───────────────────────────────────────────────────

    /// Run a full code-quality scan on a workspace directory.
    pub fn scan_quality(&self, workspace_root: &Path) -> Result<code_quality::CodeQualityReport> {
        code_quality::scan_quality(workspace_root)
    }

    // ── Commit Convention ──────────────────────────────────────────────

    /// Validate a commit message against Conventional Commits.
    pub fn validate_commit(&self, message: &str) -> Result<(), Vec<String>> {
        commit::validate_commit_message(message)
    }

    /// Parse a commit message into its structured fields.
    pub fn parse_commit(&self, message: &str) -> Option<commit::CommitInfo> {
        commit::parse_commit_message(message)
    }

    /// Get a commit template suggestion.
    pub fn suggest_commit_template(&self, type_: &str, scope: Option<&str>) -> String {
        commit::suggest_template(type_, scope)
    }

    // ── Combined Audit ─────────────────────────────────────────────────

    /// Run all audits (layering + code quality) and return combined results.
    pub fn audit_all(&self, workspace_root: &Path) -> Result<CombinedAuditReport> {
        let layering = self.audit_layering(workspace_root)?;
        let quality = self.scan_quality(workspace_root)?;

        Ok(CombinedAuditReport { layering, quality })
    }
}

/// Combined report from all audits.
#[derive(Debug, Clone)]
pub struct CombinedAuditReport {
    pub layering: arch_audit::AuditReport,
    pub quality: code_quality::CodeQualityReport,
}

impl CombinedAuditReport {
    /// Format the full report as a human-readable string.
    pub fn format(&self) -> String {
        let mut out = String::new();

        // ── Layering ──
        out.push_str(&format!(
            "=== Architecture Layering Audit ===\n\
             Files scanned: {}\n",
            self.layering.files_scanned
        ));
        if self.layering.violations.is_empty() {
            out.push_str("  ✅ No layering violations found.\n");
        } else {
            for v in &self.layering.violations {
                out.push_str(&format!(
                    "  [{}] {}:{} — {}\n",
                    v.severity, v.file, v.line, v.message
                ));
            }
        }

        // ── Code Quality ──
        out.push_str(&format!(
            "\n=== Code Quality Scan ===\n\
             Files scanned: {}\n",
            self.quality.files_scanned
        ));
        if self.quality.findings.is_empty() {
            out.push_str("  ✅ No code-quality issues found.\n");
        } else {
            let by_rule = self.quality.count_by_rule();
            out.push_str("  By rule:\n");
            for (rule, count) in &by_rule {
                out.push_str(&format!("    {rule}: {count}\n"));
            }
            out.push_str("  Top findings:\n");
            for f in self.quality.findings.iter().take(20) {
                out.push_str(&format!(
                    "    [{}] {}:{} — {}: {}\n",
                    f.severity, f.file, f.line, f.rule, f.message
                ));
            }
            if self.quality.findings.len() > 20 {
                out.push_str(&format!(
                    "    ... and {} more findings.\n",
                    self.quality.findings.len() - 20
                ));
            }
        }

        out
    }
}

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

    #[test]
    fn engine_lists_skills() {
        let engine = BestPracticeEngine::new();
        let names = engine.list_skills();
        assert!(names.contains(&"clean-code"));
    }
}