use crate::view::telephone::TelephoneView;
use std::collections::HashSet;
use super::name::{NameView};
use super::address::AddressView;
use genpdf::Element as _;
use genpdf::{elements, style, fonts};
use qrcodegen::QrCode;
use qrcodegen::QrCodeEcc;
use yew::prelude::*;
use vcard::{VCard, VCardError};
use crate::viewmodel::utility::*;
use crate::viewmodel::name::Name;
use crate::viewmodel::address::Address;
use crate::viewmodel::telephone::Telephone;
use crate::viewmodel::VCardPropertyInputObject;


pub struct MainView {
    link: ComponentLink<Self>,
    error: Vec<String>,
    name: Name,
    address: Address,
    telephone: Telephone,
    download: Option<Download>,
    selected_option: DownloadOption,
}

pub enum Msg {
    UpdateName(Name),
    UpdateAddress(Address),
    UpdateTelephone(Telephone),
    Generate(DownloadOption),
    Nope,
}

impl Component for MainView {
    type Message = Msg;
    type Properties = ();

    fn create(_props: Self::Properties, link: ComponentLink<Self>) -> Self {
        MainView { 
            link, 
            error: vec![], 
            name: Name::new(), 
            address: Address::new(),
            telephone: Telephone::new(),
            download: None, 
            selected_option: DownloadOption::VCard 
        }
    }

    fn update(&mut self, msg: Self::Message) -> ShouldRender {
        self.error.clear();
        match msg {
            Msg::UpdateName(value) => {
                self.name = value;
                self.link.send_message(Msg::Generate(self.selected_option));
            },
            Msg::UpdateAddress(value) => {
                self.address = value;
                self.link.send_message(Msg::Generate(self.selected_option));
            },
            Msg::UpdateTelephone(value) => {
                self.telephone = value;
                self.link.send_message(Msg::Generate(self.selected_option));
            },
            Msg::Generate(option) => {
                self.selected_option = option;

                let vcard_content = match self.generate_vcard() {
                    Ok(vcard) => Some(vcard.to_string()),
                    Err(VCardError::FormatError(err)) => {
                        self.error.push(err.to_string());
                        None
                    }
                    Err(VCardError::EmptyFormatName) => {
                        self.error.push(String::from("At least one of the name fields should be filled out."));
                        None
                    }
                };

                match option {
                    DownloadOption::VCard => {
                        if vcard_content.is_some() {
                            self.download = Some(
                                Download { 
                                    file_name: format!("{}.vcs", self.name.formatted_name()), 
                                    content: vcard_content.unwrap().to_string(), 
                                    mime_type: MimeType::VCard,
                                }
                            )
                        }
                    }
                    DownloadOption::QrCode => {
                        if vcard_content.is_some() {
                            match QrCode::encode_text(vcard_content.as_ref().unwrap(), QrCodeEcc::Low) {
                                Ok(qr) => self.download = Some(
                                    Download {
                                        file_name: format!("QR-Code VCard {}.svg", self.name.formatted_name()),
                                        content: qr.to_svg_string(4),
                                        mime_type: MimeType::SVG,
                                    }
                                ),
                                Err(_) => self.error.push(String::from("Sorry, VCard is too long!")),
                            };
                        }
                    }
                    DownloadOption::PDF => {
                        match self.generate_pdf() {
                            Ok(pdf) => self.download = Some(
                                Download {
                                    file_name: format!("Visitenkarten {}.pdf", self.name.formatted_name()),
                                    content: pdf,
                                    mime_type: MimeType::PDF,
                                }
                            ),
                            Err(_) => self.error.push(String::from("Unexpected error while generating the PDF. Please contact me about it.")),
                        }
                    }
                }
            }
            Msg::Nope => return false,
        };
        if self.error.len() > 0 {
            self.download = None;
        }
        true
    }

    fn change(&mut self, _props: Self::Properties) -> ShouldRender {
        false
    }

    fn view(&self) -> Html {

        let download_options = self.link.callback(|e: ChangeData|
            match e {
                ChangeData::Select(v) => match v.value().as_str() {
                    "vcard" => Msg::Generate(DownloadOption::VCard),
                    "pdf" => Msg::Generate(DownloadOption::PDF),
                    "qrcode" => Msg::Generate(DownloadOption::QrCode),
                    _ => Msg::Nope,
                },
                _ => Msg::Nope,
            }
        );

        html!{
            <>
                <main>
                    <section class="hero">
                        <div class="hero-body">
                            <div class="container is-max-widescreen">
                                <h1 class="title">{ "A Generator for vCards" }</h1>
                                <h2 class="subtitle">{ "Supports generating vCards (.vcf), print-ready PDF business cards and QR Codes" }</h2>
                            </div>
                        </div>
                    </section>

                    <section class="section">
                        <div class="container is-max-widescreen">

                            { self.render_errors() }

                            <NameView oninput=self.link.callback(|n: Name| Msg::UpdateName(n)) />

                            <AddressView oninput=self.link.callback(|a: Address| Msg::UpdateAddress(a)) />

                            <TelephoneView oninput=self.link.callback(|t: Telephone| Msg::UpdateTelephone(t)) />

                            <div class="block level-left">
                                <div class="select level-item">
                                    <select id="download_options" onchange=download_options>
                                        <option value="vcard">{ "VCard (.vcf)" }</option>
                                        <option value="pdf">{ "Print-ready PDF" }</option>
                                        <option value="qrcode">{ "QR Code" }</option>
                                    </select>
                                </div>
                                
                                { self.render_download() }
                            </div>

                            <div class="block">
                                { self.render_preview() }
                            </div>

                        </div>
                    </section>
                </main>

                <footer class="footer">
                    <div class="content has-text-centered">
                        <p>
                            <strong>{ "VCard Generator" }</strong> { " by " } <a href="https://jelemux.dev">{ "Jeremias Weber" }</a>{ ". "}
                            { "The source code is licenced " } <a href="http://opensource.org/licenses/mit-license.php">{ "MIT" }</a>{"."}
                        </p>
                    </div>
                </footer>
            </>
        }
    }
}

impl MainView {
    fn render_errors(&self) -> Html {
        html!{
            <>
                {
                    for self.error.iter().map(|err| 
                        html!{
                            <div class="notification is-danger is-light">
                                { err }
                            </div>
                        }
                    ) 
                }
            </>
        }
    }
    fn render_download(&self) -> Html {
        if self.download.is_some() {
            let download = self.download.as_ref().unwrap();

            html!{
                <a href=download.as_data_link() download=download.file_name class="button is-primary level-item" >
                    { "Download" }
                </a>
            }
        } else {
            html!{}
        }
    }
    fn render_preview(&self) -> Html {
        if self.download.is_some() {
            let download = self.download.as_ref().unwrap();

            match download.mime_type {
                MimeType::PDF => html!{
                    <iframe src=download.as_data_link() alt="PDF Preview" width="400" height="550"/>
                },
                MimeType::VCard => {
                    html!{
                        <pre>
                            <code> { download.content.clone() } </code>
                        </pre>
                    }
                }
                MimeType::SVG => html!{
                    <img src=download.as_data_link() alt="Image Preview" class="image is-square" width="300" height="300"/>
                },
            }
        } else {
            html!{}
        }
    }
    fn generate_vcard(&self) -> Result<VCard, VCardError> {
        match VCard::from_formatted_name_str(&self.name.formatted_name()) {
            Ok(vcard) => {
                let mut vcard = vcard;

                let names = {
                    let mut names = HashSet::new();
                    names.insert(self.name.to_vcard_property().unwrap());

                    names
                };

                let addresses = {
                    let mut addresses = HashSet::new();
                    addresses.insert(self.address.to_vcard_property().unwrap());

                    addresses
                };

                let telephones = {
                    let mut telephones = HashSet::new();
                    telephones.insert(self.telephone.to_vcard_property().unwrap());
                    
                    telephones
                };

                vcard.names = Some(vcard::Set::from_hash_set(names).unwrap());
                vcard.addresses = Some(vcard::Set::from_hash_set(addresses).unwrap());
                vcard.telephones = Some(vcard::Set::from_hash_set(telephones).unwrap());

                Ok(vcard)
            }
            Err(err) => Err(err),
        }
    }
    fn generate_pdf(&self) -> Result<String, ()>{
        let regular_bytes = include_bytes!("/usr/share/fonts/liberation/LiberationSans-Regular.ttf");
        let regular_font_data = fonts::FontData::new(regular_bytes.to_vec(), Some(printpdf::BuiltinFont::Helvetica)).expect("font data should be correct");

        let bold_bytes = include_bytes!("/usr/share/fonts/liberation/LiberationSans-Bold.ttf");
        let bold_font_data = fonts::FontData::new(bold_bytes.to_vec(), Some(printpdf::BuiltinFont::HelveticaBold)).expect("font data should be correct");

        let italic_bytes = include_bytes!("/usr/share/fonts/liberation/LiberationSans-Italic.ttf");
        let italic_font_data = fonts::FontData::new(italic_bytes.to_vec(), Some(printpdf::BuiltinFont::HelveticaOblique)).expect("font data should be correct");

        let bold_italic_bytes = include_bytes!("/usr/share/fonts/liberation/LiberationSans-BoldItalic.ttf");
        let bold_italic_font_data = fonts::FontData::new(bold_italic_bytes.to_vec(), Some(printpdf::BuiltinFont::HelveticaBoldOblique)).expect("font data should be correct");

        let font_family = fonts::FontFamily{ 
            regular: regular_font_data, 
            bold: bold_font_data, 
            italic: italic_font_data, 
            bold_italic: bold_italic_font_data 
        };

        let mut doc = genpdf::Document::new(font_family);

        doc.set_title("BCard test");
        doc.set_minimal_conformance();
        
        let mut decorator = genpdf::SimplePageDecorator::new();
        decorator.set_margins(10);
        doc.set_page_decorator(decorator);
        
        doc.set_line_spacing(1.25);

        doc.push(
            elements::Paragraph::new("genpdf Demo Document")
                .aligned(elements::Alignment::Center)
                .styled(style::Style::new().bold().with_font_size(20)),
        );

        // TODO fill doc with real data

        let mut buf: Vec<u8> = Vec::new();
        match doc.render(&mut buf) {
            Ok(_) => Ok(match String::from_utf8(buf) {
                Ok(s) => s,
                Err(_) => return Err(()),
            }),
            Err(_) => Err(()),
        }
    }
}