const objectPath = require('object-path');
const utils = require('./utils')

const NAME_REGEX = /^[a-z0-9_-]+$/;
const DESCRIPTION_REGEX = /^[A-Z]{1}.+\.$/

function required() {
    return (path, input) => {
        input = input && input.trim()
        if(!input) {
            return `Property '${path}' must be set! value=${input}`
        }
    }
}

function length(opts) {
    return (path, input) => {
        input = input && input.trim() || ''
        if(opts.min && input.length < opts.min) {
            return `Property '${path}' must have at least ${opts.min} characters! actual=${input.length}`
        }
        if(opts.max  && input.length > opts.max) {
            return `Property '${path}' must not have more than ${opts.max} characters! actual=${input.length}`
        }  
    }
}

function regex(regex) {
    return (path, input, msgs) => {
        input = input && input.trim()
        if(!input.match(regex)) {
            return `Property '${path}' must comply to pattern ${regex}! value=${input}`
        }
    }
}


const linterMappings = [
    { 
        path: 'name', 
        linters: [ 
            { label: 'is set', validator: required() }, 
            { label: 'has at least 4 characters', validator: length({ min: 4 }) }, 
            { label: 'format is valid', validator: regex(NAME_REGEX) } 
        ] 
    },
    { 
        path: 'description', 
        linters: [ 
            { label: 'is set', validator: required() }, 
            { label: 'has at least 4 characters', validator: length({ min: 4 }) }, 
            { label: 'format is valid', validator: regex(DESCRIPTION_REGEX) }  
        ] 
    }
] 


module.exports.lint = function(spec) {
    let results = {
        success: true
    }
    linterMappings.forEach(element => {
        let value = objectPath.get(spec, element.path);
        element.linters.forEach(linter => {
            let msg = linter.validator(element.path, value)
            if(msg) {
                results.success = false
            }
            msg = msg || 'OK'
            results[element.path] = msg;
            console.log(utils.formatColumns(utils.formatColumns(element.path, linter.label, 12), msg))
        });
    });
    return results;
}

module.exports.regex = {
    NAME_REGEX,
    DESCRIPTION_REGEX
}

module.exports.validators = {
    required,
    length,
    regex,
}