import { Component } from '../../lib/vues6/vues6.js'
import { utility } from '../service/Utility.service.js'
import { location_service } from '../service/Location.service.js'
import { resource_service } from '../service/Resource.service.js'
import { action_service } from '../service/Action.service.js'

const template = `
<div class="card col-12 col-sm-10 offset-sm-1 col-md-8 offset-md-2 col-xl-6 offset-xl-3">
    <h3 class="card-title mb-4 mt-4">
        <button class="btn-lg btn" @click="back"><i class="fa fa-arrow-left"></i></button> {{ title }}
    </h3>
    <form v-on:submit.prevent="do_nothing" v-if="is_ready">
        <div class="form-group" v-for="field of definition.fields">
            <span v-if="field.type.startsWith('select')">
                <label :for="uuid+field.field">{{ field.name }}</label>
                <select
                    :id="uuid+field.field" 
                    class="form-control" 
                    v-model="data[field.field]"
                    :required="field.required"
                    :readonly="mode === 'view'"
                    :multiple="!!field.type.endsWith('.multiple')"
                >
                    <option v-for="option of field.options" :value="option.value">{{ typeof option.display === 'function' ? option.display(option) : option.display }}</option>
                </select>
                <small class="form-text" style="color: darkred;" v-if="field.error">{{ field.error }}</small>
            </span>
            <span v-if="field.type === 'text'">
                <label :for="uuid+field.field">{{ field.name }}</label>
                <input
                    type="text"
                    class="form-control"
                    :id="uuid+field.field"
                    v-model="data[field.field]"
                    :required="field.required"
                    :placeholder="field.placeholder"
                    :readonly="mode === 'view'"
                    ref="input"
                >
                <small class="form-text" style="color: darkred;" v-if="field.error">{{ field.error }}</small>
            </span>
        </div>
    </form>
    <div class="col-12 text-right mb-4 mr-0 mt-2">
        <span style="color: darkred;" class="font-italic mr-3" v-if="error_message">{{ error_message }}</span>
        <span class="font-italic mr-3 text-muted" v-if="other_message">{{ other_message }}</span>
        <button
            class="btn btn-primary"
            type="button"
            v-if="mode !== 'view'"
            @click="save_click"
        >Save</button>                
    </div>
</div>
`

const title_map = {
    insert: 'Create',
    update: 'Edit',
    view: 'View',
}

export default class FormComponent extends Component {
    static get selector() {
        return 'cobalt-form'
    }

    static get template() {
        return template
    }

    static get props() {
        return ['resource', 'form_id', 'initial_mode']
    }

    definition = {}
    data = {}
    uuid = ''
    title = ''
    error_message = ''
    other_message = ''

    is_ready = false
    mode = ''
    id = ''

    reset() {
        this.definition = {}
        this.data = {}
        this.uuid = ''
        this.title = ''
        this.error_message = ''
        this.other_message = ''
        this.is_ready = false
    }

    async vue_on_create(internal = false) {
        if ( !internal ) {
            this.mode = this.initial_mode
            this.id = this.form_id
            this.resource_class = await resource_service.get(this.resource)
        } else {
            this.reset()
        }

        this.uuid = utility.uuid()
        await this.load()
        await this.init()
    }

    async init() {
        for ( const field of this.definition.fields ) {
            if ( field.type.startsWith('select.dynamic') ) {
                field._options = field._options || field.options
                const rsc = await resource_service.get(field._options.resource)

                field.options = (await rsc.list()).map(item => {
                    return {
                        display: typeof field._options.display === 'function' ? field._options.display(item) : item[field._options.display || 'display'],
                        value: typeof field._options.value === 'function' ? field._options.value(item) : item[field._options.value || 'display'],
                    }
                })
            }

            if ( field.type.endsWith('.multiple') ) {
                this.data[field.field] = []
            }
        }

        this.is_ready = true
        this.$nextTick(() => {
            if ( this.mode !== 'view' ) this.$refs.input[0].focus()
        })
    }

    async load() {
        this.definition = this.resource_class.form_definition
        if (this.mode !== 'insert') {
            this.data = await this.resource_class.get(this.id)
        }

        this.title = title_map[this.mode] + ' ' + this.resource_class.item
    }

    async on_create() {
        this.id = this.data.id
        this.mode = 'update'
        await this.vue_on_create(true)
        location_service.set_query(`mode=update&id=${this.id}`)
    }

    async save_click() {
        if ( !this.validate() ) return
        try {
            if (this.mode === 'insert') {
                this.data = await this.resource_class.create(this.data)
                await this.on_create()
            } else if (this.mode === 'update') {
                await this.resource_class.update(this.id, this.data)
            }

            this.error_message = ''
            this.other_message = `The ${this.resource_class.item} was saved.`
        } catch (e) {
            if ( e.response && e.response.data && e.response.data.message )
                this.error_message = e.response.data.message
            else this.error_message = 'An unknown error occurred while saving the form.'
        }
    }

    validate() {
        let valid = true
        for ( const field of this.definition.fields ) {
            if ( field.required && (!(field.field in this.data) || !this.data[field.field]) ) {
                field.error = 'This field is required.'
                valid = false
            } else {
                field.error = ''
            }
        }

        this.$forceUpdate()

        return valid
    }

    back() {
        return action_service.perform({
            text: '',
            type: 'resource',
            resource: this.resource,
            action: 'list',
        })
    }

    do_nothing() {}
}