import * as fs from "node:fs";
import * as path from "node:path";
import { BaseAgent, AgentContext, AgentResult } from "./base.js";

interface EcosystemSummary {
  frameworks: string[];
  apis: string[];
  patterns: string[];
  tooling: string[];
  technologyDecisions: Array<{ id: string; decision: string; confidence: number }>;
}

const FRAMEWORK_PATTERNS: Record<string, string[]> = {
  react: ["react"],
  vue: ["vue"],
  angular: ["@angular/core"],
  svelte: ["svelte"],
  express: ["express"],
  fastify: ["fastify"],
  nestjs: ["@nestjs/core"],
  next: ["next"],
  nuxt: ["nuxt"],
  koa: ["koa"],
  jest: ["jest"],
  vitest: ["vitest"],
};

const API_PATTERNS: Record<string, string[]> = {
  graphql: ["graphql", "apollo", "@apollo"],
  rest: ["express", "fastify", "restana"],
  grpc: ["grpc", "@grpc"],
  websocket: ["ws", "socket.io"],
};

const PATTERN_PATTERNS: Record<string, string[]> = {
  microservices: ["@nestjs/microservices", "amqplib", "kafkajs"],
  middleware: ["express", "koa", "fastify"],
  cqrs: ["@nestjs/cqrs"],
  dependency_injection: ["inversify", "tsyringe", "@nestjs/core"],
  test_driven: ["jest", "vitest", "mocha"],
};

const TOOLING_PATTERNS: Record<string, string[]> = {
  typescript: ["typescript"],
  eslint: ["eslint"],
  prettier: ["prettier"],
  webpack: ["webpack"],
  vite: ["vite"],
  rollup: ["rollup"],
  esbuild: ["esbuild"],
  docker: [],
  ci_cd: [],
};

export class ProjectResearcherAgent extends BaseAgent {
  readonly name = "project-researcher";
  readonly description = "Researches the domain ecosystem for a new project.";
  readonly workflow = "research";

  async execute(context: AgentContext): Promise<AgentResult> {
    const start = Date.now();
    this.log("Researching project domain ecosystem...");

    if (context.backend) {
      const result = await this.executeViaBackend(
        context,
        `Research the domain ecosystem for: ${context.specification}`
      );
      return { ...result, duration_ms: Date.now() - start };
    }

    const summary = this.mechanicalProjectResearch(context.project_path);
    const output = this.formatSummary(summary);

    return {
      success: true,
      output,
      artifacts_created: [],
      decisions: summary.technologyDecisions.length,
      escalations: 0,
      duration_ms: Date.now() - start,
    };
  }

  mechanicalProjectResearch(projectPath: string): EcosystemSummary {
    const pkg = this.readPackageJson(projectPath);
    const tsconfig = this.readTsconfig(projectPath);
    const techDecisions = this.readTechDecisions(projectPath);
    const summary = this.categorizeFindings(pkg, tsconfig, techDecisions);
    return summary;
  }

  readPackageJson(projectPath: string): Record<string, unknown> {
    const pkgPath = path.join(projectPath, "package.json");
    if (!fs.existsSync(pkgPath)) return {};
    try {
      return JSON.parse(fs.readFileSync(pkgPath, "utf-8"));
    } catch {
      return {};
    }
  }

  readTsconfig(projectPath: string): Record<string, unknown> {
    const tsconfigPath = path.join(projectPath, "tsconfig.json");
    if (!fs.existsSync(tsconfigPath)) return {};
    try {
      return JSON.parse(fs.readFileSync(tsconfigPath, "utf-8"));
    } catch {
      return {};
    }
  }

  readTechDecisions(projectPath: string): Array<{ id: string; decision: string; confidence: number }> {
    const decisions: Array<{ id: string; decision: string; confidence: number }> = [];
    const techCategories = ["technology_choice", "implementation_approach", "architecture"];

    try {
      const { execSync } = require("node:child_process");
      const logContent = execSync(
        `git log --all --format="%B" -100`,
        { cwd: projectPath, encoding: "utf-8", timeout: 5000 }
      );

      const categoryRegex = /category:\s*(\S+)/g;
      const decisionRegex = /decisions:\s*\n((?:\s+-\s+.+\n?)+)/g;
      let catMatch;
      let match;

      const blocks: Array<{ categories: string[]; items: string[] }> = [];
      let currentCategories: string[] = [];

      while ((catMatch = categoryRegex.exec(logContent)) !== null) {
        currentCategories.push(catMatch[1].toLowerCase());
      }

      while ((match = decisionRegex.exec(logContent)) !== null) {
        const items = match[1].split("\n").filter((l: string) => l.trim().startsWith("-"));
        blocks.push({
          categories: [...currentCategories],
          items: items.map((i: string) => i.replace(/^\s*-\s*/, "").trim()),
        });
      }

      for (const block of blocks) {
        const isTech = block.categories.some((c) => techCategories.includes(c));
        if (!isTech && block.categories.length > 0) continue;

        for (const item of block.items) {
          const idMatch = item.match(/D-(\d+)/);
          const id = idMatch ? `D-${idMatch[1]}` : `D-${decisions.length + 1}`;
          const confMatch = item.match(/confidence[:\s]+(\d+\.?\d*)/);
          const confidence = confMatch ? parseFloat(confMatch[1]) : 0.5;
          decisions.push({ id, decision: item, confidence });
        }
      }
    } catch {
      // git not available or no commits
    }

    return decisions;
  }

  categorizeFindings(
    pkg: Record<string, unknown>,
    tsconfig: Record<string, unknown>,
    techDecisions: Array<{ id: string; decision: string; confidence: number }>
  ): EcosystemSummary {
    const allDeps: string[] = [];
    const deps = pkg.dependencies as Record<string, string> | undefined;
    const devDeps = pkg.devDependencies as Record<string, string> | undefined;
    if (deps) allDeps.push(...Object.keys(deps));
    if (devDeps) allDeps.push(...Object.keys(devDeps));

    const frameworks: string[] = [];
    for (const [name, depPatterns] of Object.entries(FRAMEWORK_PATTERNS)) {
      if (depPatterns.some((p) => allDeps.includes(p))) {
        frameworks.push(name);
      }
    }

    const apis: string[] = [];
    for (const [name, depPatterns] of Object.entries(API_PATTERNS)) {
      if (depPatterns.some((p) => allDeps.includes(p))) {
        apis.push(name);
      }
    }

    const patterns: string[] = [];
    for (const [name, depPatterns] of Object.entries(PATTERN_PATTERNS)) {
      if (depPatterns.some((p) => allDeps.includes(p))) {
        patterns.push(name);
      }
    }

    const tooling: string[] = [];
    for (const [name, depPatterns] of Object.entries(TOOLING_PATTERNS)) {
      if (depPatterns.some((p) => allDeps.includes(p))) {
        tooling.push(name);
      }
    }

    const compilerOptions = tsconfig.compilerOptions as Record<string, unknown> | undefined;
    if (compilerOptions) {
      const target = compilerOptions.target as string | undefined;
      if (target) tooling.push(`es_target:${target.toLowerCase()}`);
      const module = compilerOptions.module as string | undefined;
      if (module) tooling.push(`module_system:${module.toLowerCase()}`);
    }

    const scripts = pkg.scripts as Record<string, string> | undefined;
    if (scripts) {
      if (scripts.build) tooling.push("build_script");
      if (scripts.test) tooling.push("test_script");
      if (scripts.lint) tooling.push("lint_script");
    }

    const engines = pkg.engines as Record<string, string> | undefined;
    if (engines && engines.node) {
      tooling.push(`node:${engines.node}`);
    }

    return {
      frameworks,
      apis,
      patterns,
      tooling,
      technologyDecisions: techDecisions,
    };
  }

  private formatSummary(summary: EcosystemSummary): string {
    const lines: string[] = ["Ecosystem Summary:", ""];

    lines.push("Frameworks:");
    for (const f of summary.frameworks) {
      lines.push(`  - ${f}`);
    }
    if (summary.frameworks.length === 0) lines.push("  (none detected)");

    lines.push("");
    lines.push("APIs:");
    for (const a of summary.apis) {
      lines.push(`  - ${a}`);
    }
    if (summary.apis.length === 0) lines.push("  (none detected)");

    lines.push("");
    lines.push("Patterns:");
    for (const p of summary.patterns) {
      lines.push(`  - ${p}`);
    }
    if (summary.patterns.length === 0) lines.push("  (none detected)");

    lines.push("");
    lines.push("Tooling:");
    for (const t of summary.tooling) {
      lines.push(`  - ${t}`);
    }
    if (summary.tooling.length === 0) lines.push("  (none detected)");

    lines.push("");
    lines.push("Technology Decisions:");
    for (const d of summary.technologyDecisions) {
      lines.push(`  [${d.id}|conf=${d.confidence.toFixed(2)}] ${d.decision}`);
    }
    if (summary.technologyDecisions.length === 0) lines.push("  (none found)");

    return lines.join("\n");
  }
}