import * as fs from "node:fs";
import * as path from "node:path";
import { execSync } from "node:child_process";
import { VerificationLayer, VerificationResult, VerificationCheck } from "./types.js";

interface CodeFinding {
  severity: "P0" | "P1" | "P2" | "P3";
  category: string;
  persona: "security" | "performance" | "maintainability";
  message: string;
  file?: string;
}

const SECURITY_REVIEW_PATTERNS: Array<{
  pattern: RegExp;
  severity: "P0" | "P1" | "P2";
  category: string;
  message: string;
}> = [
  {
    pattern: /(?:exec|execSync|spawn|spawnSync)\s*\(\s*[^'"]*[\$`]/g,
    severity: "P0",
    category: "command_injection",
    message: "Command execution with dynamic input — injection risk",
  },
  {
    pattern: /eval\s*\(\s*[^'"]*\$\{/g,
    severity: "P0",
    category: "code_injection",
    message: "eval() with dynamic content — code injection risk",
  },
  {
    pattern: /(?:innerHTML|outerHTML|insertAdjacentHTML)\s*=/g,
    severity: "P0",
    category: "xss",
    message: "Unsanitized HTML assignment — XSS risk",
  },
  {
    pattern: /(?:password|secret|api[_-]?key|token)\s*[:=]\s*['"][^'"]{3,}['"]/gi,
    severity: "P0",
    category: "credential_exposure",
    message: "Hardcoded credential in source",
  },
  {
    pattern: /(?:__proto__|constructor\s*\[|prototype\s*\[)/g,
    severity: "P0",
    category: "prototype_pollution",
    message: "Prototype chain manipulation — privilege escalation risk",
  },
  {
    pattern: /jwt\.decode\s*\(/g,
    severity: "P0",
    category: "auth_bypass",
    message: "JWT decoded without verification — authentication bypass",
  },
  {
    pattern: /(?:md5|sha1|des|rc4)\s*\(/gi,
    severity: "P1",
    category: "weak_crypto",
    message: "Weak cryptographic algorithm",
  },
  {
    pattern: /JSON\.parse\s*\(\s*(?:req|ctx|input|data|body|params)\.\w+/g,
    severity: "P1",
    category: "unsafe_deserialization",
    message: "Unsafe deserialization of untrusted input",
  },
  {
    pattern: /catch\s*\(\w*\)\s*\{\s*\}/g,
    severity: "P0",
    category: "swallowed_errors",
    message: "Empty catch block — errors silently swallowed",
  },
];

const PERFORMANCE_REVIEW_PATTERNS: Array<{
  pattern: RegExp;
  severity: "P1" | "P2";
  category: string;
  message: string;
}> = [
  {
    pattern: /await\s+.*(?:readFileSync|writeFileSync|execSync)/g,
    severity: "P1",
    category: "blocking_io",
    message: "Synchronous I/O in async context — blocks event loop",
  },
  {
    pattern: /(?:execSync|spawnSync)\s*\(\s*['"]/g,
    severity: "P1",
    category: "sync_exec",
    message: "Synchronous process spawn — blocks event loop",
  },
  {
    pattern: /setTimeout\s*\((?![^)]*clearTimeout)/g,
    severity: "P2",
    category: "timer_leak",
    message: "setTimeout without clearTimeout — potential timer leak",
  },
  {
    pattern: /\.(?:on|addEventListener)\s*\(['"]\w+['"]/g,
    severity: "P2",
    category: "listener_leak",
    message: "Event listener registration — verify corresponding .off() exists",
  },
  {
    pattern: /\.map\s*\(\s*(?:async\s+)?\([^)]*\)\s*=>\s*(?!.*(?:filter|slice|take|limit))/g,
    severity: "P2",
    category: "unbounded_iteration",
    message: "Full array traversal without pagination or limit",
  },
  {
    pattern: /express\.json\s*\(\s*\)/g,
    severity: "P1",
    category: "no_body_limit",
    message: "JSON body parser without size limit — DoS risk",
  },
];

const MAINTAINABILITY_REVIEW_PATTERNS: Array<{
  pattern: RegExp;
  severity: "P1" | "P2" | "P3";
  category: string;
  message: string;
}> = [
  {
    pattern: /(?:as\s+any\b|:\s*any\b|<any>|any\[\s*\])/g,
    severity: "P1",
    category: "type_safety",
    message: "Use of 'any' type — loses type safety",
  },
  {
    pattern: /\bvar\s+/g,
    severity: "P1",
    category: "modern_js",
    message: "Use of 'var' — prefer 'const' or 'let'",
  },
  {
    pattern: /\b(?:TODO|FIXME|HACK|XXX)\b/g,
    severity: "P2",
    category: "tech_debt",
    message: "Technical debt marker found",
  },
  {
    pattern: /console\.(log|warn|error)\s*\(/g,
    severity: "P2",
    category: "logging",
    message: "Direct console.log usage — consider structured logging",
  },
  {
    pattern: /(?:return|throw)\s+[^;]+;\s*\n\s*(?:return|throw|const|let|var|function)/g,
    severity: "P1",
    category: "dead_code",
    message: "Code after return/throw — unreachable dead code",
  },
];

export class QualityVerification extends VerificationLayer {
  readonly layer = 4;
  readonly name = "Code Quality";

  async verify(projectPath: string, phase: number): Promise<VerificationResult> {
    const start = Date.now();
    const checks: VerificationCheck[] = [];

    const securityFindings = this.scanWithPersona(projectPath, SECURITY_REVIEW_PATTERNS, "security");
    const perfFindings = this.scanWithPersona(projectPath, PERFORMANCE_REVIEW_PATTERNS, "performance");
    const maintFindings = this.scanWithPersona(projectPath, MAINTAINABILITY_REVIEW_PATTERNS, "maintainability");
    const allFindings = [...securityFindings, ...perfFindings, ...maintFindings];

    const p0Findings = allFindings.filter((f) => f.severity === "P0");
    const p1Findings = allFindings.filter((f) => f.severity === "P1");
    const p2p3Findings = allFindings.filter((f) => f.severity === "P2" || f.severity === "P3");

    checks.push(this.checkP0Findings(p0Findings));
    checks.push(this.checkP1Findings(p1Findings));
    checks.push(this.checkP2P3Findings(p2p3Findings));
    checks.push(this.checkSecurityReview(securityFindings));
    checks.push(this.checkPerformanceReview(perfFindings));
    checks.push(this.checkMaintainabilityReview(maintFindings));
    checks.push(this.checkTypeScriptStrictness(projectPath));
    checks.push(this.checkConsistentNaming(projectPath));
    checks.push(this.checkTypeScriptCompilation(projectPath));

    const hasP0Fail = p0Findings.length > 0;
    const passed = !hasP0Fail;

    return {
      layer: this.layer,
      name: this.name,
      passed,
      checks,
      summary: `${allFindings.length} findings across 3 personas (P0: ${p0Findings.length}, P1: ${p1Findings.length}, P2/P3: ${p2p3Findings.length})`,
      duration_ms: Date.now() - start,
    };
  }

  private scanWithPersona(
    projectPath: string,
    patterns: Array<{ pattern: RegExp; severity: "P0" | "P1" | "P2" | "P3"; category: string; message: string }>,
    persona: CodeFinding["persona"]
  ): CodeFinding[] {
    const findings: CodeFinding[] = [];
    const srcDir = path.join(projectPath, "src");

    if (!fs.existsSync(srcDir)) {
      return findings;
    }

    this.scanDirectory(srcDir, projectPath, patterns, persona, findings);
    return findings;
  }

  private scanDirectory(
    dir: string,
    projectPath: string,
    patterns: Array<{ pattern: RegExp; severity: "P0" | "P1" | "P2" | "P3"; category: string; message: string }>,
    persona: CodeFinding["persona"],
    findings: CodeFinding[]
  ): void {
    const entries = fs.readdirSync(dir, { withFileTypes: true });
    for (const entry of entries) {
      const fullPath = path.join(dir, entry.name);
      if (entry.isDirectory() && entry.name !== "node_modules") {
        this.scanDirectory(fullPath, projectPath, patterns, persona, findings);
      } else if (
        entry.isFile() &&
        entry.name.endsWith(".ts") &&
        !entry.name.endsWith(".test.ts") &&
        !entry.name.endsWith(".d.ts")
      ) {
        const content = fs.readFileSync(fullPath, "utf-8");
        for (const { pattern, severity, category, message } of patterns) {
          pattern.lastIndex = 0;
          if (pattern.test(content)) {
            findings.push({
              severity,
              category,
              persona,
              message: `${message} (${path.relative(projectPath, fullPath)})`,
              file: path.relative(projectPath, fullPath),
            });
          }
        }
      }
    }
  }

  private checkP0Findings(p0Findings: CodeFinding[]): VerificationCheck {
    if (p0Findings.length === 0) {
      return this.check(
        "P0 findings (auto-fix)",
        "pass",
        "No critical code quality issues found"
      );
    }
    return this.check(
      "P0 findings (auto-fix)",
      "fail",
      `${p0Findings.length} P0 finding(s) — must be fixed`,
      p0Findings.map((f) => `[${f.persona}|${f.category}] ${f.message}`).join("\n")
    );
  }

  private checkP1Findings(p1Findings: CodeFinding[]): VerificationCheck {
    if (p1Findings.length === 0) {
      return this.check(
        "P1 findings (review)",
        "pass",
        "No P1 findings"
      );
    }
    return this.check(
      "P1 findings (review)",
      "warning",
      `${p1Findings.length} P1 finding(s) flagged for post-hoc review`,
      p1Findings.map((f) => `[${f.persona}|${f.category}] ${f.message}`).join("\n")
    );
  }

  private checkP2P3Findings(findings: CodeFinding[]): VerificationCheck {
    if (findings.length === 0) {
      return this.check(
        "P2/P3 findings (informational)",
        "pass",
        "No P2/P3 findings"
      );
    }
    return this.check(
      "P2/P3 findings (informational)",
      "pass",
      `${findings.length} informational finding(s)`,
      findings.map((f) => `[${f.persona}|${f.category}] ${f.message}`).join("\n")
    );
  }

  private checkSecurityReview(findings: CodeFinding[]): VerificationCheck {
    if (findings.length === 0) {
      return this.check("Security persona review", "pass", "No security review findings");
    }
    const p0 = findings.filter((f) => f.severity === "P0").length;
    return this.check(
      "Security persona review",
      p0 > 0 ? "fail" : "warning",
      `${findings.length} finding(s) from security reviewer (P0: ${p0})`,
      findings.map((f) => `[${f.category}] ${f.message}`).join("\n")
    );
  }

  private checkPerformanceReview(findings: CodeFinding[]): VerificationCheck {
    if (findings.length === 0) {
      return this.check("Performance persona review", "pass", "No performance review findings");
    }
    return this.check(
      "Performance persona review",
      "warning",
      `${findings.length} finding(s) from performance reviewer`,
      findings.map((f) => `[${f.category}] ${f.message}`).join("\n")
    );
  }

  private checkMaintainabilityReview(findings: CodeFinding[]): VerificationCheck {
    if (findings.length === 0) {
      return this.check("Maintainability persona review", "pass", "No maintainability review findings");
    }
    return this.check(
      "Maintainability persona review",
      "pass",
      `${findings.length} finding(s) from maintainability reviewer`,
      findings.map((f) => `[${f.category}] ${f.message}`).join("\n")
    );
  }

  private checkTypeScriptStrictness(projectPath: string): VerificationCheck {
    const tsconfigPath = path.join(projectPath, "tsconfig.json");
    if (!fs.existsSync(tsconfigPath)) {
      return this.check("TypeScript strictness", "warning", "No tsconfig.json found");
    }

    const content = fs.readFileSync(tsconfigPath, "utf-8");
    const jsonContent = content.replace(/\/\/.*$/gm, "").replace(/\/\*[\s\S]*?\*\//g, "");

    try {
      const tsconfig = JSON.parse(jsonContent);
      const strict = tsconfig.compilerOptions?.strict;
      const noImplicitAny = tsconfig.compilerOptions?.noImplicitAny;

      if (strict) {
        return this.check("TypeScript strictness", "pass", "TypeScript strict mode is enabled");
      }
      if (noImplicitAny) {
        return this.check("TypeScript strictness", "pass", "noImplicitAny is enabled");
      }
      return this.check(
        "TypeScript strictness",
        "warning",
        "TypeScript strict mode is not enabled — consider enabling for better type safety"
      );
    } catch {
      return this.check("TypeScript strictness", "warning", "Could not parse tsconfig.json");
    }
  }

  private checkConsistentNaming(projectPath: string): VerificationCheck {
    const srcDir = path.join(projectPath, "src");
    if (!fs.existsSync(srcDir)) {
      return this.check("Consistent naming", "skipped", "No src/ directory found");
    }

    const tsFiles: string[] = [];
    this.collectFiles(srcDir, tsFiles);

    const kebabCaseFiles = tsFiles.filter((f) => path.basename(f).includes("-") && !path.basename(f).includes(".test."));
    const camelCaseFiles = tsFiles.filter((f) => /^[a-z][a-zA-Z0-9]*\.ts$/.test(path.basename(f)) && !path.basename(f).includes("-"));
    const pascalCaseFiles = tsFiles.filter((f) => /^[A-Z]/.test(path.basename(f)));

    const conventions: string[] = [];
    if (kebabCaseFiles.length > camelCaseFiles.length && kebabCaseFiles.length > pascalCaseFiles.length) {
      conventions.push("kebab-case dominant");
    } else if (camelCaseFiles.length > 0) {
      conventions.push("camelCase files present");
    }

    return this.check(
      "Consistent naming",
      "pass",
      `${tsFiles.length} source files, naming conventions: ${conventions.join(", ") || "mixed"}`
    );
  }

  private checkTypeScriptCompilation(projectPath: string): VerificationCheck {
    const tsconfigPath = path.join(projectPath, "tsconfig.json");
    if (!fs.existsSync(tsconfigPath)) {
      return this.check("TypeScript compilation", "skipped", "No tsconfig.json found");
    }

    try {
      execSync("npx tsc --noEmit 2>&1", {
        cwd: projectPath,
        encoding: "utf-8",
        timeout: 60000,
        stdio: ["pipe", "pipe", "pipe"],
      });
      return this.check("TypeScript compilation", "pass", "TypeScript compiles without errors");
    } catch (err) {
      const execErr = err as { stdout?: string };
      const output = execErr.stdout || "";
      const errorCount = (output.match(/error TS/g) || []).length;
      return this.check(
        "TypeScript compilation",
        errorCount > 5 ? "fail" : "warning",
        `${errorCount} TypeScript compilation error(s)`
      );
    }
  }

  private collectFiles(dir: string, files: string[]): void {
    const entries = fs.readdirSync(dir, { withFileTypes: true });
    for (const entry of entries) {
      const fullPath = path.join(dir, entry.name);
      if (entry.isDirectory() && entry.name !== "node_modules") {
        this.collectFiles(fullPath, files);
      } else if (entry.name.endsWith(".ts") && !entry.name.endsWith(".d.ts")) {
        files.push(fullPath);
      }
    }
  }
}