// Headless test: verify custom function blocks generate JS correctly.
const Blockly = require('blockly');
const { javascriptGenerator, Order } = require('blockly/javascript');

const FN_COLOR = '#E91E63';
const OVAL_COLOR = '#FF8C1A';

function escXml(s) {
  return String(s).replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;').replace(/'/g, '&apos;');
}

// --- Simulated app blocks (statement blocks return strings; value blocks tuples) ---
javascriptGenerator.forBlock['rb_js_set_var'] = function (block) {
  const name = block.getFieldValue('name') || 'myVar';
  let value = '';
  const t = block.getInputTargetBlock('value');
  if (t) {
    const tuple = javascriptGenerator.blockToCode(t, Order.ATOMIC);
    value = Array.isArray(tuple) ? tuple[0] : tuple || '';
  }
  const code = `myVar${''} = ${value || 'undefined'};`;
  return block.outputConnection ? [code, Order.ATOMIC] : code; // statement -> string
};
javascriptGenerator.forBlock['rb_js_const_number'] = function (block) {
  return [String(block.getFieldValue('value') ?? 0), Order.ATOMIC];
};
javascriptGenerator.forBlock['rb_js_console'] = function (block) {
  let value = '';
  const t = block.getInputTargetBlock('value');
  if (t) {
    const tuple = javascriptGenerator.blockToCode(t, Order.ATOMIC);
    value = Array.isArray(tuple) ? tuple[0] : tuple || '';
  }
  const code = `console.log(${value || "''"});`;
  return block.outputConnection ? [code, Order.ATOMIC] : code;
};

// --- Minimal app block definitions ---
Blockly.Blocks['rb_js_set_var'] = {
  init() {
    this.appendDummyInput().appendField('set var').appendField('myVar', 'name');
    this.appendValueInput('value');
    this.setPreviousStatement(true);
    this.setNextStatement(true);
  },
};
Blockly.Blocks['rb_js_const_number'] = {
  init() {
    this.appendDummyInput().appendField('value').appendField(new Blockly.FieldNumber(0), 'value');
    this.setOutput(true);
  },
};
Blockly.Blocks['rb_js_console'] = {
  init() {
    this.appendDummyInput().appendField('print');
    this.appendValueInput('value');
    this.setPreviousStatement(true);
    this.setNextStatement(true);
  },
};

// --- Register the custom function block types (mirrors customFunctionBlocks.ts) ---
function parseFnData(block) {
  try {
    const d = JSON.parse(String(block.data || '{}'));
    if (d && typeof d === 'object' && typeof d.name === 'string') return d;
  } catch {}
  return null;
}
function paramSegsOf(segments) {
  return (segments || []).filter((s) => s.kind === 'param');
}
function encodeName(name) {
  return String(name).replace(/%/g, '\\u0025').replace(/\s+/g, '_').replace(/\W/g, (ch) => {
    return '%' + ch.codePointAt(0).toString(16).toUpperCase();
  });
}
function fnParamNames(data) {
  return paramSegsOf(data.segments).map((s) => encodeName(s.name));
}

Blockly.Blocks['rb_custom_fn'] = {
  init() {
    this.setColour(FN_COLOR);
    this.appendDummyInput();
    this.setInputsInline(true);
  },
  domToMutation(m) {
    try {
      const data = {
        name: m.getAttribute('name') || '',
        segments: JSON.parse(m.getAttribute('segments') || '[]'),
        asyncFn: m.getAttribute('async') === 'true',
        returns: m.getAttribute('returns') === 'true',
      };
      this.data = JSON.stringify(data);
      // rebuild layout: define + param value inputs + body statement
      for (const input of [...this.inputList]) this.removeInput(input.name);
      const row = this.appendDummyInput();
      row.appendField('define');
      row.appendField(data.name, 'name');
      let pendingText = '';
      let idx = 0;
      for (const seg of data.segments) {
        if (seg.kind === 'text') pendingText += seg.text;
        else {
          const vi = this.appendValueInput('PARAM' + idx);
          if (pendingText) vi.appendField(pendingText);
          pendingText = '';
          if (seg.type === 'boolean') vi.setCheck('Boolean');
          idx++;
        }
      }
      const props = this.appendDummyInput();
      if (pendingText) props.appendField(pendingText);
      props.appendField(data.asyncFn ? 'TRUE' : 'FALSE', 'asyncFn');
      props.appendField('async');
      props.appendField(data.returns ? 'TRUE' : 'FALSE', 'returns');
      props.appendField('return value');
      this.appendStatementInput('body');
      this.setInputsInline(true);
    } catch (e) {
      throw e;
    }
  },
  mutationToDom() {
    const m = Blockly.utils.xml.createElement('mutation');
    const d = parseFnData(this) || { name: '', segments: [] };
    m.setAttribute('name', String(d.name || ''));
    m.setAttribute('segments', JSON.stringify(d.segments || []));
    m.setAttribute('async', d.asyncFn ? 'true' : 'false');
    m.setAttribute('returns', d.returns ? 'true' : 'false');
    return m;
  },
};
Blockly.Blocks['rb_custom_call'] = {
  init() {
    this.setColour(FN_COLOR);
    this.setPreviousStatement(true);
    this.setNextStatement(true);
    this.appendDummyInput();
    this.setInputsInline(true);
  },
  domToMutation(m) {
    const data = {
      name: m.getAttribute('name') || '',
      segments: JSON.parse(m.getAttribute('segments') || '[]'),
      returns: m.getAttribute('returns') === 'true',
    };
    this.data = JSON.stringify(data);
    for (const input of [...this.inputList]) this.removeInput(input.name);
    const head = this.appendDummyInput();
    head.appendField(data.name, 'fnName');
    let pendingText = '';
    let idx = 0;
    for (const seg of data.segments) {
      if (seg.kind === 'text') pendingText += seg.text;
      else {
        const vi = this.appendValueInput('PARAM' + idx);
        if (pendingText) vi.appendField(pendingText);
        pendingText = '';
        if (seg.type === 'boolean') vi.setCheck('Boolean');
        idx++;
      }
    }
    const trail = this.appendDummyInput();
    if (pendingText) trail.appendField(pendingText);
    this.setInputsInline(true);
  },
  mutationToDom() {
    const m = Blockly.utils.xml.createElement('mutation');
    const d = parseFnData(this) || { name: '', segments: [] };
    m.setAttribute('name', String(d.name || ''));
    m.setAttribute('segments', JSON.stringify(d.segments || []));
    return m;
  },
};
Blockly.Blocks['rb_custom_param_var'] = {
  init() {
    this.setColour(OVAL_COLOR);
    this.setOutput(true);
    this.appendDummyInput().appendField('param', 'name');
    this.setInputsInline(true);
  },
};

// generators use second param `gen` (mirrors the fix)
javascriptGenerator.forBlock['rb_custom_fn'] = function (block, gen) {
  const data = parseFnData(block);
  const name = encodeName(block.getFieldValue('name') || (data && data.name) || 'myFunction');
  const asyncFn = block.getFieldValue('asyncFn') === 'TRUE';
  const params = (data ? fnParamNames(data) : []).join(', ');
  const body = gen.statementToCode(block, 'body');
  return `${asyncFn ? 'async ' : ''}function ${name}(${params}) {\n${body}\n}`;
};
function callCode(block, gen, isValue) {
  const data = parseFnData(block);
  const name = encodeName((data && data.name) || 'myFunction');
  const params = paramSegsOf((data && data.segments) || []);
  const args = params
    .map((_, i) => {
      try {
        return gen.valueToCode(block, 'PARAM' + i, Order.ATOMIC) || 'undefined';
      } catch {
        return 'undefined';
      }
    })
    .join(', ');
  return isValue ? `${name}(${args})` : `${name}(${args});`;
}
javascriptGenerator.forBlock['rb_custom_call'] = function (block, gen) {
  return callCode(block, gen, false);
};
javascriptGenerator.forBlock['rb_custom_call_value'] = function (block, gen) {
  return [callCode(block, gen, true), Order.ATOMIC];
};
javascriptGenerator.forBlock['rb_custom_param_var'] = function (block) {
  return [encodeName(String(block.getFieldValue('name') || '')), Order.ATOMIC];
};

// --- Build a workspace with a function hat containing body blocks + a caller ---
const xml = `
<xml>
  <block type="rb_custom_fn">
    <mutation name="greet" segments='[{"kind":"text","text":"Say hi to "},{"kind":"param","name":"who","type":"variable"}]' async="false" returns="false"></mutation>
    <field name="name">greet</field>
    <field name="asyncFn">FALSE</field>
    <field name="returns">FALSE</field>
    <statement name="body">
      <block type="rb_js_console">
        <value name="value">
          <block type="rb_custom_param_var">
            <field name="name">who</field>
            <data>greet</data>
          </block>
        </value>
      </block>
    </statement>
    <value name="PARAM0">
      <block type="rb_custom_param_var">
        <field name="name">who</field>
        <data>greet</data>
      </block>
    </value>
  </block>
  <block type="rb_custom_call">
    <mutation name="greet" segments='[{"kind":"text","text":"Say hi to "},{"kind":"param","name":"who","type":"variable"}]' returns="false"></mutation>
    <value name="PARAM0">
      <block type="rb_js_const_number"><field name="value">42</field></block>
    </value>
  </block>
</xml>`;

const ws = new Blockly.Workspace();
Blockly.Xml.domToWorkspace(Blockly.utils.xml.textToDom(xml), ws);

let ok = true;
function check(label, actual, expected) {
  const pass = actual === expected;
  if (!pass) ok = false;
  console.log((pass ? 'PASS' : 'FAIL') + ' ' + label);
  if (!pass) {
    console.log('  expected: ' + JSON.stringify(expected));
    console.log('  actual:   ' + JSON.stringify(actual));
  }
}

// Generate from the whole workspace
javascriptGenerator.init(ws);
const whole = javascriptGenerator.workspaceToCode(ws);
const expectedWhole = `function greet(who) {
  console.log(who);
}
greet(42);`;
check('workspaceToCode', whole, expectedWhole);

// Generate the fn hat alone via blockToCode (as generateCodeFromBlock does)
const fnBlock = ws.getTopBlocks(true).find((b) => b.type === 'rb_custom_fn');
const fnTuple = javascriptGenerator.blockToCode(fnBlock);
check('fn blockToCode is string', typeof fnTuple === 'string', true);
check('fn blockToCode', fnTuple, `function greet(who) {
  console.log(who);
}`);

// Caller alone
const callBlock = ws.getTopBlocks(true).find((b) => b.type === 'rb_custom_call');
const callStr = javascriptGenerator.blockToCode(callBlock);
check('call blockToCode is string', typeof callStr === 'string', true);
check('call blockToCode', callStr, 'greet(42);');

// Caller with an empty param socket must not emit `greet(, )` (syntax error);
// the empty arg falls back to `undefined`.
const emptyXml = `<xml><block type="rb_custom_call">` +
  `<mutation name="greet" segments='[{"kind":"text","text":"Say hi to "},{"kind":"param","name":"who","type":"variable"}]' returns="false"></mutation>` +
  `</block></xml>`;
const ws2 = new Blockly.Workspace();
Blockly.Xml.domToWorkspace(Blockly.utils.xml.textToDom(emptyXml), ws2);
javascriptGenerator.init(ws2);
const emptyCall = javascriptGenerator.workspaceToCode(ws2);
check('empty-arg caller -> undefined', emptyCall, 'greet(undefined);');

process.exit(ok ? 0 : 1);