extern crate console_error_panic_hook;
use genpdf::Element as _;
use genpdf::{elements, style, fonts};
use qrcodegen::QrCode;
use qrcodegen::QrCodeEcc;
use wasm_bindgen::prelude::*;
use js_sys;
use yew::prelude::*;
use vcard::{VCard, VCardError};
use std::panic;

fn init() {
    panic::set_hook(Box::new(console_error_panic_hook::hook));
}

struct Download {
    file_name: String,
    content: Box<dyn AsRef<[u8]>>,
    mime_type: MimeType,
}

impl Download {
    fn as_data_link(&self) -> String {
        let data = base64::encode(&*self.content);
        let uri_component: String = js_sys::encode_uri_component(&data).into();

        format!("data:{};base64,{}", self.mime_type.as_text(), uri_component)
    }
}

enum MimeType {
    PDF,
    VCard,
    SVG,
}

impl MimeType {
    fn as_text(&self) -> &str {
        match self {
            MimeType::PDF => "application/pdf",
            MimeType::VCard => "text/vcard",
            MimeType::SVG => "image/svg+xml",
        }
    }
}

pub struct Form {
    link: ComponentLink<Self>,
    error: Vec<String>,
    formatted_name: String,
    download: Option<Download>,
}

pub enum Msg {
    UpdateFormattedName(String),
    GenerateVCard,
    GeneratePdf,
    GenerateQrCode,
    Nope,
}

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

    fn create(_props: Self::Properties, link: ComponentLink<Self>) -> Self {
        Self { link, error: vec![], formatted_name: String::new(), download: None, }
    }

    fn update(&mut self, msg: Self::Message) -> ShouldRender {
        self.error.clear();
        match msg {
            Msg::UpdateFormattedName(value) => self.formatted_name = String::from(value),
            Msg::GenerateVCard => {
                match self.generate_vcard() {
                    Ok(vcard) => self.download = Some(
                        Download { 
                            file_name: format!("{}.vcs",self.formatted_name), 
                            content: Box::new(vcard.to_string()), 
                            mime_type: MimeType::VCard,
                        }
                    ),
                    Err(VCardError::FormatError(err)) => self.error.push(err.to_string()),
                    Err(VCardError::EmptyFormatName) => self.error.push(String::from("A VCard should have at least one formatted name.")),
                };
            }
            Msg::GeneratePdf => {
                match self.generate_pdf() {
                    Ok(pdf) => self.download = Some(
                        Download {
                            file_name: format!("Visitenkarten {}.pdf", self.formatted_name),
                            content: Box::new(pdf),
                            mime_type: MimeType::PDF,
                        }
                    ),
                    Err(_) => self.error.push(String::from("Unexpected error while generating the PDF. Please contact me about it.")),
                }
            }
            Msg::GenerateQrCode => {
                let mut vcard_content = None;
                match self.generate_vcard() {
                    Ok(vcard) => vcard_content = Some(vcard.to_string()),
                    Err(VCardError::FormatError(err)) => self.error.push(err.to_string()),
                    Err(VCardError::EmptyFormatName) => self.error.push(String::from("A VCard should have at least one formatted name.")),
                };
                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.formatted_name),
                                content: Box::new(qr.to_svg_string(4)),
                                mime_type: MimeType::SVG,
                            }
                        ),
                        Err(_) => self.error.push(String::from("Sorry, VCard is too long!")),
                    };
                }
            }
            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 formatted_name_input = self.link.batch_callback(|e: InputData| 
            vec![Msg::UpdateFormattedName(e.value), Msg::GenerateVCard]
        );

        let download_options = self.link.callback(|e: ChangeData|
            match e {
                ChangeData::Select(v) => match v.value().as_str() {
                    "vcard" => Msg::GenerateVCard,
                    "pdf" => Msg::GeneratePdf,
                    "qrcode" => Msg::GenerateQrCode,
                    _ => Msg::Nope,
                },
                _ => Msg::Nope,
            }
        );

        html!{
            <div class="container">
                <div class="banner row">
                    <div class="span twelve">
                        <h4>{ "A Generator for vCards" }</h4>
                        <h5>{ "Supports generating vCards (.vcf), print-ready PDF business cards and QR Codes" }</h5>
                    </div>
                </div>
                { self.render_error() }
                <h4 class="explainer">{ "Name" }</h4>
                <form class="row">
                    <label for="formatted_name">{ "Formatted name: " }</label>
                    <input id="formatted_name" type="text" oninput=formatted_name_input/>
                    <br/>
                    <label for="prefix">{ "Prefix: " }</label>
                    <input id="prefix" type="text"/>
                    <br/>
                    <label for="first_name">{ "First name: " }</label>
                    <input id="first_name" type="text"/>

                    <label for="middle_name">{ "Middle name: " }</label>
                    <input id="middle_name" type="text"/>

                    <label for="last_name">{ "Last name: " }</label>
                    <input id="last_name" type="text"/>
                    <br/>
                    <label for="suffix">{ "Suffix: " }</label>
                    <input id="suffix" type="text"/>
                </form>
                <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>
                
                { self.render_download() }

            </div>
        }
    }
}

impl Form {
    fn generate_vcard(&self) -> Result<VCard, VCardError> {
        match VCard::from_formatted_name_str(&self.formatted_name) {
            Ok(vcard) => Ok(vcard),
            Err(err) => Err(err),
        }
    }
    fn generate_pdf(&self) -> Result<Vec<u8>, ()>{
        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();
        doc.set_margins(10);
        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(buf),
            Err(_) => Err(()),
        }
    }
    fn render_error(&self) -> Html {
        html!{
            <>
                {
                    for self.error.iter().map(|err| 
                        html!{
                            <div class="alert danger">
                                <p>{ err }</p>
                            </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 success small" >
                    { "Download" }
                </a>
            }
        } else {
            html!{}
        }
    }/*
    fn render_qrcode(&self) -> Html {
        if self.qr_code.is_some() {
            let data = base64::encode(self.qr_code.as_ref().unwrap());
            let uri_component: String = js_sys::encode_uri_component(&data).into();
            let src = format!("data:image/svg+xml;base64,{}", uri_component);

            html!{
                <img src=src alt="QR Code" width="200" height="200"/>
            }
        } else {
            html!{}
        }
    }*/
}


#[wasm_bindgen(start)]
pub fn run_app() {
    init();
    App::<Form>::new().mount_to_body();
}