/**
 * Best-practice engine — embedded skills, Conventional Commits validation,
 * and lightweight architecture/quality scans. Mirrors `crate::best_practice`.
 */
import * as fs from "node:fs";
import * as path from "node:path";

interface Skill {
  name: string;
  description: string;
  content: string;
}

const SKILLS: Skill[] = [
  {
    name: "clean-code",
    description: "Clean Code principles and naming conventions",
    content:
      "Clean Code:\n- Use meaningful, intention-revealing names.\n- Functions should do one thing and be short.\n- Avoid duplication (DRY).\n- Comments should explain 'why', not 'what'.\n- Favor composition over deep inheritance.",
  },
  {
    name: "commit-convention",
    description: "Conventional Commits (Bahasa Indonesia) rules",
    content:
      "Conventional Commits:\n- Format: <type>(<scope>): <subject>\n- Types: feat, fix, chore, docs, refactor, test, style, perf, ci, build, revert\n- Subject: imperative, lowercase, no trailing period.\n- Example: 'feat(auth): tambah login PKCE'",
  },
  {
    name: "layering",
    description: "Clean Architecture layering rules (domain → application → infrastructure → interfaces)",
    content:
      "Clean Architecture:\n- domain: pure types, zero I/O.\n- application: ports + use cases.\n- infrastructure: concrete adapters.\n- interfaces: presentation.\n- Dependencies point inward; domain depends on nothing.",
  },
];

const COMMIT_TYPES = ["feat", "fix", "chore", "docs", "refactor", "test", "style", "perf", "ci", "build", "revert"];

export class BestPracticeEngine {
  listSkills(): string[] {
    return SKILLS.map((s) => s.name);
  }
  skillSummaries(): Array<[string, string]> {
    return SKILLS.map((s) => [s.name, s.description] as [string, string]);
  }
  getSkill(name: string): string | undefined {
    return SKILLS.find((s) => s.name === name)?.content;
  }

  parseCommit(msg: string): { type_: string; scope: string | null; breaking: boolean; description: string } | null {
    const m = /^([a-z]+)(?:\(([^)]+)\))?(!)?:\s*(.+)$/.exec(msg.trim().split("\n")[0] ?? "");
    if (!m) return null;
    return { type_: m[1]!, scope: m[2] ?? null, breaking: m[3] === "!", description: (m[4] ?? "").trim() };
  }

  validateCommit(msg: string): string[] {
    const errors: string[] = [];
    const first = (msg.trim().split("\n")[0] ?? "").trim();
    if (first === "") { errors.push("Commit message is empty."); return errors; }
    const parsed = this.parseCommit(first);
    if (!parsed) {
      errors.push("Does not match Conventional Commits: <type>(<scope>): <subject>");
      return errors;
    }
    if (!COMMIT_TYPES.includes(parsed.type_)) {
      errors.push(`Unknown type '${parsed.type_}'. Valid types: ${COMMIT_TYPES.join(", ")}`);
    }
    if (parsed.description === "") {
      errors.push("Subject is empty.");
    } else if (!/^[a-z]/.test(parsed.description)) {
      errors.push("Subject should start with a lowercase letter.");
    }
    if (parsed.description.endsWith(".")) {
      errors.push("Subject should not end with a period.");
    }
    if (first.length > 72) {
      errors.push("Subject is longer than 72 characters.");
    }
    return errors;
  }

  suggestCommitTemplate(type_: string, scope: string | null): string {
    if (!COMMIT_TYPES.includes(type_)) type_ = "feat";
    return `${type_}${scope ? `(${scope})` : ""}: <imperative description>`;
  }

  auditLayering(ws: string): { filesScanned: number; violations: Array<{ severity: string; file: string; line: number; message: string }> } {
    const violations: Array<{ severity: string; file: string; line: number; message: string }> = [];
    let filesScanned = 0;
    const scan = (dir: string) => {
      let entries: fs.Dirent[];
      try { entries = fs.readdirSync(dir, { withFileTypes: true }); } catch { return; }
      for (const e of entries) {
        if (e.name === ".git" || e.name === "node_modules" || e.name === "target") continue;
        const full = path.join(dir, e.name);
        if (e.isDirectory()) scan(full);
        else if (e.name.endsWith(".ts") || e.name.endsWith(".tsx")) {
          filesScanned++;
          const lines = fs.readFileSync(full, "utf8").split("\n");
          lines.forEach((line, i) => {
            if (line.includes("@zesdex/infrastructure") && full.includes("/domain/")) {
              violations.push({ severity: "error", file: full, line: i + 1, message: "domain must not depend on infrastructure" });
            }
          });
        }
      }
    };
    scan(ws);
    return { filesScanned, violations };
  }
}