/**
 * @fileoverview Rule that warns when identifier names are shorter or longer
 *               than the values provided in configuration.
 * @author Burak Yigit Kaya aka BYK
 * @copyright 2015 Burak Yigit Kaya. All rights reserved.
 * @copyright 2015 Mathieu M-Gosselin. All rights reserved.
 */

"use strict";

//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------

module.exports = {
    meta: {
        docs: {
            description: "enforce minimum and maximum identifier lengths",
            category: "Stylistic Issues",
            recommended: false
        },

        schema: [
            {
                "type": "object",
                "properties": {
                    "min": {
                        "type": "number"
                    },
                    "max": {
                        "type": "number"
                    },
                    "exceptions": {
                        "type": "array",
                        "uniqueItems": true,
                        "items": {
                            "type": "string"
                        }
                    },
                    "properties": {
                        "enum": ["always", "never"]
                    }
                },
                "additionalProperties": false
            }
        ]
    },

    create: function(context) {
        var options = context.options[0] || {};
        var minLength = typeof options.min !== "undefined" ? options.min : 2;
        var maxLength = typeof options.max !== "undefined" ? options.max : Infinity;
        var properties = options.properties !== "never";
        var exceptions = (options.exceptions ? options.exceptions : [])
            .reduce(function(obj, item) {
                obj[item] = true;

                return obj;
            }, {});

        var SUPPORTED_EXPRESSIONS = {
            "MemberExpression": properties && function(parent) {
                return !parent.computed && (

                    // regular property assignment
                    (parent.parent.left === parent || // or the last identifier in an ObjectPattern destructuring
                    parent.parent.type === "Property" && parent.parent.value === parent &&
                    parent.parent.parent.type === "ObjectPattern" && parent.parent.parent.parent.left === parent.parent.parent)
                );
            },
            "AssignmentPattern": function(parent, node) {
                return parent.left === node;
            },
            "VariableDeclarator": function(parent, node) {
                return parent.id === node;
            },
            "Property": properties && function(parent, node) {
                return parent.key === node;
            },
            "ImportDefaultSpecifier": true,
            "RestElement": true,
            "FunctionExpression": true,
            "ArrowFunctionExpression": true,
            "ClassDeclaration": true,
            "FunctionDeclaration": true,
            "MethodDefinition": true,
            "CatchClause": true
        };

        return {
            Identifier: function(node) {
                var name = node.name;
                var parent = node.parent;

                var isShort = name.length < minLength;
                var isLong = name.length > maxLength;

                if (!(isShort || isLong) || exceptions[name]) {
                    return;  // Nothing to report
                }

                var isValidExpression = SUPPORTED_EXPRESSIONS[parent.type];

                if (isValidExpression && (isValidExpression === true || isValidExpression(parent, node))) {
                    context.report(
                        node,
                        isShort ?
                            "Identifier name '{{name}}' is too short. (< {{min}})" :
                            "Identifier name '{{name}}' is too long. (> {{max}})",
                        { name: name, min: minLength, max: maxLength }
                    );
                }
            }
        };
    }
};
