#!/usr/bin/env node
/**
 * Clojure → EmojiScript Bytecode Compiler CLI
 * Phase 2: Terminal tool for backend/batch compilation
 *
 * Usage:
 *   ./clojure-to-bytecode.mjs <file.clj> [--output file.emojis] [--verbose]
 *   ./clojure-to-bytecode.mjs --help
 *   ./clojure-to-bytecode.mjs --version
 */

import fs from 'fs';
import path from 'path';
import { fileURLToPath } from 'url';

const __dirname = path.dirname(fileURLToPath(import.meta.url));

// Inline the compiler (so no dependencies)
class ClojureParser {
  constructor(source) {
    this.source = source;
    this.pos = 0;
    this.line = 1;
    this.col = 1;
  }

  parse() {
    const forms = [];
    while (this.pos < this.source.length) {
      this.skipWhitespaceAndComments();
      if (this.pos >= this.source.length) break;
      forms.push(this.parseForm());
    }
    return forms;
  }

  parseForm() {
    this.skipWhitespaceAndComments();
    const ch = this.peek();

    if (ch === '(') return this.parseList();
    if (ch === '[') return this.parseVector();
    if (ch === '{') return this.parseMap();
    if (ch === "'") return this.parseQuote();
    if (ch === '"') return this.parseString();
    if (ch === ':') return this.parseKeyword();
    if (/[0-9-]/.test(ch)) return this.parseNumber();
    if (/[a-zA-Z_*+?!<>=&|]/.test(ch)) return this.parseSymbol();

    throw new Error(`Unexpected character: ${ch} at line ${this.line}, col ${this.col}`);
  }

  parseList() {
    this.consume('(');
    const elements = [];
    this.skipWhitespaceAndComments();

    while (this.peek() !== ')') {
      elements.push(this.parseForm());
      this.skipWhitespaceAndComments();
    }

    this.consume(')');
    return { type: 'list', elements };
  }

  parseVector() {
    this.consume('[');
    const elements = [];
    this.skipWhitespaceAndComments();

    while (this.peek() !== ']') {
      elements.push(this.parseForm());
      this.skipWhitespaceAndComments();
    }

    this.consume(']');
    return { type: 'vector', elements };
  }

  parseMap() {
    this.consume('{');
    const pairs = [];
    this.skipWhitespaceAndComments();

    while (this.peek() !== '}') {
      const key = this.parseForm();
      this.skipWhitespaceAndComments();
      const value = this.parseForm();
      pairs.push([key, value]);
      this.skipWhitespaceAndComments();
    }

    this.consume('}');
    return { type: 'map', pairs };
  }

  parseQuote() {
    this.consume("'");
    const form = this.parseForm();
    return { type: 'quote', value: form };
  }

  parseString() {
    this.consume('"');
    let str = '';
    while (this.peek() !== '"') {
      if (this.peek() === '\\') {
        this.pos++;
        const escaped = this.source[this.pos];
        str += escaped === 'n' ? '\n' : escaped === 't' ? '\t' : escaped;
      } else {
        str += this.peek();
      }
      this.pos++;
    }
    this.consume('"');
    return { type: 'string', value: str };
  }

  parseKeyword() {
    this.consume(':');
    let kw = '';
    while (this.pos < this.source.length && /[a-zA-Z0-9_-]/.test(this.peek())) {
      kw += this.peek();
      this.pos++;
    }
    return { type: 'keyword', value: kw };
  }

  parseNumber() {
    let num = '';
    if (this.peek() === '-') num += this.consume('-');
    while (this.pos < this.source.length && /[0-9.]/.test(this.peek())) {
      num += this.peek();
      this.pos++;
    }
    return { type: 'number', value: parseFloat(num) };
  }

  parseSymbol() {
    let sym = '';
    while (this.pos < this.source.length && /[a-zA-Z0-9_*+?!<>=&|/-]/.test(this.peek())) {
      sym += this.peek();
      this.pos++;
    }
    return { type: 'symbol', value: sym };
  }

  skipWhitespaceAndComments() {
    while (this.pos < this.source.length) {
      const ch = this.peek();

      if (/\s/.test(ch)) {
        if (ch === '\n') {
          this.line++;
          this.col = 0;
        }
        this.pos++;
        this.col++;
      } else if (ch === ';') {
        while (this.pos < this.source.length && this.peek() !== '\n') {
          this.pos++;
        }
      } else {
        break;
      }
    }
  }

  peek() {
    return this.source[this.pos];
  }

  consume(expected) {
    if (this.peek() !== expected) {
      throw new Error(`Expected '${expected}', got '${this.peek()}' at line ${this.line}`);
    }
    this.pos++;
    this.col++;
    return expected;
  }
}

class ClojureToEmojiScript {
  constructor(verbose = false) {
    this.bytecode = [];
    this.constants = [];
    this.symbolTable = new Map();
    this.labels = new Map();
    this.labelCounter = 0;
    this.verbose = verbose;
  }

  compile(clojureSource) {
    try {
      const parser = new ClojureParser(clojureSource);
      const forms = parser.parse();

      for (const form of forms) {
        this.compileForm(form);
      }

      return {
        success: true,
        bytecode: this.bytecode,
        constants: this.constants,
        symbolTable: Object.fromEntries(this.symbolTable),
        emojiscript: this.generateEmojiscript(),
      };
    } catch (err) {
      return {
        success: false,
        error: err.message,
        phase: 'compile',
      };
    }
  }

  compileForm(form) {
    if (form.type === 'number') {
      this.emitPush(form.value);
    } else if (form.type === 'string') {
      this.emitPush(form.value);
    } else if (form.type === 'symbol') {
      this.handleSymbol(form.value);
    } else if (form.type === 'list') {
      this.compileList(form);
    } else if (form.type === 'vector') {
      this.compileVector(form);
    } else if (form.type === 'keyword') {
      this.emitPush(`:${form.value}`);
    } else if (form.type === 'quote') {
      this.emitPush(form.value);
    }
  }

  compileList(form) {
    if (form.elements.length === 0) {
      this.emitPush(null);
      return;
    }

    const [fn, ...args] = form.elements;

    if (fn.type === 'symbol') {
      const op = fn.value;

      if (op === '+') {
        for (const arg of args) this.compileForm(arg);
        for (let i = 1; i < args.length; i++) this.bytecode.push('➕');
        return;
      }

      if (op === '-') {
        for (const arg of args) this.compileForm(arg);
        for (let i = 1; i < args.length; i++) this.bytecode.push('➖');
        return;
      }

      if (op === '*') {
        for (const arg of args) this.compileForm(arg);
        for (let i = 1; i < args.length; i++) this.bytecode.push('✖️');
        return;
      }

      if (op === '/') {
        for (const arg of args) this.compileForm(arg);
        for (let i = 1; i < args.length; i++) this.bytecode.push('➗');
        return;
      }

      if (op === 'and') {
        for (const arg of args) this.compileForm(arg);
        for (let i = 1; i < args.length; i++) this.bytecode.push('🤝');
        return;
      }

      if (op === 'or') {
        for (const arg of args) this.compileForm(arg);
        for (let i = 1; i < args.length; i++) this.bytecode.push('👐');
        return;
      }

      if (op === 'if') {
        const [cond, thenForm, elseForm] = args;
        this.compileForm(cond);
        const jifLabel = this.genLabel();
        this.bytecode.push('❓');
        this.bytecode.push(jifLabel);
        this.compileForm(thenForm);
        const endLabel = this.genLabel();
        this.bytecode.push('➡️');
        this.bytecode.push(endLabel);
        this.labels.set(jifLabel, this.bytecode.length);
        this.compileForm(elseForm || null);
        this.labels.set(endLabel, this.bytecode.length);
        return;
      }

      this.compileForm(fn);
      for (const arg of args) {
        this.compileForm(arg);
      }
      this.bytecode.push('⚡');
      this.bytecode.push(args.length);
      return;
    }

    for (const elem of form.elements) {
      this.compileForm(elem);
    }
  }

  compileVector(form) {
    for (const elem of form.elements) {
      this.compileForm(elem);
    }
    this.bytecode.push('🏗️');
    this.bytecode.push(form.elements.length);
  }

  handleSymbol(sym) {
    if (!this.symbolTable.has(sym)) {
      this.symbolTable.set(sym, this.symbolTable.size);
    }
    this.bytecode.push('📤');
    this.bytecode.push(this.symbolTable.get(sym));
  }

  emitPush(value) {
    this.constants.push(value);
    this.bytecode.push('🔢');
    this.bytecode.push(this.constants.length - 1);
  }

  genLabel() {
    return `__label_${this.labelCounter++}`;
  }

  generateEmojiscript() {
    return this.bytecode.join(' ');
  }
}

// CLI implementation
function main() {
  const args = process.argv.slice(2);

  if (args.length === 0 || args.includes('--help') || args.includes('-h')) {
    console.log(`
Clojure → EmojiScript Bytecode Compiler v1.0.0

Usage:
  clojure-to-bytecode [input.clj] [options]

Options:
  --output, -o FILE    Write bytecode to FILE (default: input.emojis)
  --verbose, -v        Show detailed compilation info
  --help, -h           Show this help message
  --version            Show version

Examples:
  clojure-to-bytecode program.clj
  clojure-to-bytecode program.clj -o output.emojis --verbose
    `);
    process.exit(0);
  }

  if (args.includes('--version')) {
    console.log('Clojure → EmojiScript Bytecode Compiler v1.0.0');
    process.exit(0);
  }

  const inputFile = args[0];
  const verbose = args.includes('--verbose') || args.includes('-v');

  let outputFile = inputFile.replace(/\.clj$/, '.emojis');
  const outputIdx = args.indexOf('--output') + 1 || args.indexOf('-o') + 1;
  if (outputIdx > 0 && outputIdx < args.length) {
    outputFile = args[outputIdx];
  }

  if (!inputFile) {
    console.error('Error: Input file required');
    process.exit(1);
  }

  try {
    if (verbose) console.log(`[*] Reading: ${inputFile}`);
    const source = fs.readFileSync(inputFile, 'utf-8');

    if (verbose) console.log(`[*] Compiling Clojure → EmojiScript...`);
    const compiler = new ClojureToEmojiScript(verbose);
    const result = compiler.compile(source);

    if (!result.success) {
      console.error(`[✗] Compilation failed: ${result.error}`);
      process.exit(1);
    }

    if (verbose) console.log(`[*] Writing bytecode to: ${outputFile}`);
    fs.writeFileSync(outputFile, result.emojiscript, 'utf-8');

    console.log(`✓ Compiled: ${inputFile} → ${outputFile}`);
    console.log(`  Bytecode:   ${result.bytecode.length} operations`);
    console.log(`  Constants:  ${result.constants.length}`);
    console.log(`  Symbols:    ${Object.keys(result.symbolTable).length}`);
    console.log(`  Size:       ${result.emojiscript.length} bytes`);

    if (verbose) {
      console.log(`\nConstants: ${JSON.stringify(result.constants)}`);
      console.log(`Symbols: ${JSON.stringify(result.symbolTable)}`);
    }
  } catch (err) {
    console.error(`[✗] Error: ${err.message}`);
    process.exit(1);
  }
}

main();