"use strict";

module.exports = CommonJSFormatter;

var DefaultFormatter = require("./_default");
var traverse         = require("../../traverse");
var util             = require("../../util");
var t                = require("../../types");
var _                = require("lodash");

function CommonJSFormatter(file) {
  DefaultFormatter.apply(this, arguments);

  var hasNonDefaultExports = false;
  traverse(file.ast, {
    enter: function (node) {
      if (t.isExportDeclaration(node) && !node.default) hasNonDefaultExports = true;
    }
  });
  this.hasNonDefaultExports = hasNonDefaultExports;
}

util.inherits(CommonJSFormatter, DefaultFormatter);

CommonJSFormatter.prototype.importSpecifier = function (specifier, node, nodes) {
  var variableName = t.getSpecifierName(specifier);

  // import foo from "foo";
  if (t.isSpecifierDefault(specifier)) {
    var ref = util.template("require", {
      MODULE_NAME: node.source
    });
    if (!_.contains(this.file.dynamicImports, node)) {
      ref = t.callExpression(this.file.addHelper("interop-require"), [ref]);
    }
    nodes.push(t.variableDeclaration("var", [t.variableDeclarator(variableName, ref)]));
  } else {
    if (specifier.type === "ImportBatchSpecifier") {
      // import * as bar from "foo";
      nodes.push(t.variableDeclaration("var", [
        t.variableDeclarator(
          variableName,
          t.callExpression(this.file.addHelper("interop-require-wildcard"), [
            t.callExpression(t.identifier("require"), [node.source])
          ])
        )
      ]));
    } else {
      // import foo from "foo";
      nodes.push(util.template("require-assign-key", {
        VARIABLE_NAME: variableName,
        MODULE_NAME:   node.source,
        KEY:           specifier.id
      }));
    }
  }
};

CommonJSFormatter.prototype.importDeclaration = function (node, nodes) {
  // import "foo";
  nodes.push(util.template("require", {
    MODULE_NAME: node.source
  }, true));
};

CommonJSFormatter.prototype.exportDeclaration = function (node, nodes) {
  if (node.default && !this.noInteropRequire && !this.noInteropExport) {
    var declar = node.declaration;
    var assign;

    // module.exports = VALUE;
    var templateName = "exports-default-module";

    // exports = module.exports = VALUE;
    if (this.hasNonDefaultExports) templateName = "exports-default-module-override";

    if (t.isFunctionDeclaration(declar) || !this.hasNonDefaultExports) {
      assign = util.template(templateName, {
        VALUE: this._pushStatement(declar, nodes)
      }, true);

      // hoist to the top if this default is a function
      nodes.push(this._hoistExport(declar, assign, 3));
      return;
    } else {
      // this export isn't a function so we can't hoist it to the top so we need to set it
      // at the very end of the file with something like:
      //
      //   module.exports = _extends(exports["default"], exports)
      //

      assign = util.template("common-export-default-assign", {
        EXTENDS_HELPER: this.file.addHelper("extends")
      }, true);
      assign._blockHoist = 0;

      nodes.push(assign);
    }
  }

  DefaultFormatter.prototype.exportDeclaration.apply(this, arguments);
};

CommonJSFormatter.prototype.exportSpecifier = function (specifier, node, nodes) {
  this._exportSpecifier(function () {
    return t.callExpression(t.identifier("require"), [node.source]);
  }, specifier, node, nodes);
};