/*
 * meli - addressbook module
 *
 * Copyright 2019 Manos Pitsidianakis
 *
 * This file is part of meli.
 *
 * meli is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * meli is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with meli. If not, see <http://www.gnu.org/licenses/>.
 */

//! # vCard format
//!
//! This module implements the standards:
//!
//! - Version 3 (read-only) [RFC 2426: vCard MIME Directory Profile](https://datatracker.ietf.org/doc/2426)
//! - Version 4 [RFC 6350: vCard Format Specification](https://datatracker.ietf.org/doc/rfc6350/)
//! - Parameter escaping [RFC 6868 Parameter Value Encoding in iCalendar and vCard](https://datatracker.ietf.org/doc/rfc6868/)

use std::{collections::HashMap, convert::TryInto};

use super::*;
use crate::{
    error::{Error, ErrorKind, Result},
    utils::parsec::{match_literal_anycase, one_or_more, peek, prefix, take_until, Parser},
};

/* Supported vcard versions */
pub trait VCardVersion: std::fmt::Debug {}

#[derive(Debug)]
pub struct VCardVersionUnknown;
impl VCardVersion for VCardVersionUnknown {}

/// Version 4 <https://tools.ietf.org/html/rfc6350>
#[derive(Debug)]
pub struct VCardVersion4;
impl VCardVersion for VCardVersion4 {}

/// <https://tools.ietf.org/html/rfc2426>
#[derive(Debug)]
pub struct VCardVersion3;
impl VCardVersion for VCardVersion3 {}

pub struct CardDeserializer;

const HEADER_CRLF: &str = "BEGIN:VCARD\r\n"; //VERSION:4.0\r\n";
const FOOTER_CRLF: &str = "END:VCARD\r\n";
const HEADER_LF: &str = "BEGIN:VCARD\n"; //VERSION:4.0\n";
const FOOTER_LF: &str = "END:VCARD\n";
const HEADER: &str = "BEGIN:VCARD"; //VERSION:4.0";
const FOOTER: &str = "END:VCARD";

#[derive(Debug)]
pub struct VCard<T: VCardVersion>(
    HashMap<String, ContentLine>,
    std::marker::PhantomData<*const T>,
);

impl<V: VCardVersion> VCard<V> {
    pub fn new_v4() -> VCard<impl VCardVersion> {
        VCard(
            HashMap::default(),
            std::marker::PhantomData::<*const VCardVersion4>,
        )
    }
}

#[derive(Clone, Debug, Default)]
pub struct ContentLine {
    group: Option<String>,
    params: Vec<String>,
    value: String,
}

impl CardDeserializer {
    pub fn try_from_str(mut input: &str) -> Result<VCard<impl VCardVersion>> {
        input = if (!input.starts_with(HEADER_CRLF)
            || (!input.ends_with(FOOTER_CRLF) && !input.ends_with(FOOTER)))
            && (!input.starts_with(HEADER_LF)
                || (!input.ends_with(FOOTER_LF) && !input.ends_with(FOOTER)))
        {
            return Err(Error::new(format!(
                "Error while parsing vcard: input does not start or end with correct header and \
                 footer: {:?}",
                input
            ))
            .set_kind(ErrorKind::ValueError)
            .set_details(
                "vcard file entries are expected to start with a `BEGIN:VCARD` line and end with \
                 a `END:VCARD` line.",
            ));
        } else if input.starts_with(HEADER_CRLF) {
            &input[HEADER_CRLF.len()..input.len() - FOOTER_CRLF.len()]
        } else {
            &input[HEADER_LF.len()..input.len() - FOOTER_LF.len()]
        };

        let mut ret = HashMap::default();

        enum Stage {
            Group,
            Name,
            Param,
            Value,
        }
        let mut stage: Stage;

        for l in input.lines() {
            let mut el = ContentLine::default();
            let mut value_start = 0;
            let mut has_colon = false;
            stage = Stage::Group;
            let mut name = String::new();
            for i in 0..l.len() {
                let byte = l.as_bytes()[i];
                match (byte, &stage) {
                    (b'.', Stage::Group) if l.as_bytes()[i] != b'\\' => {
                        el.group = Some(l[value_start..i].to_string());
                        value_start = i + 1;
                        stage = Stage::Name;
                    }
                    (b';', Stage::Group) => {
                        name = l[value_start..i].to_string();
                        value_start = i + 1;
                        stage = Stage::Param;
                    }
                    (b';', Stage::Param) => {
                        el.params.push(l[value_start..i].to_string());
                        value_start = i + 1;
                    }
                    (b';', Stage::Name) => {
                        name = l[value_start..i].to_string();
                        value_start = i + 1;
                        stage = Stage::Param;
                    }
                    (b':', Stage::Group) | (b':', Stage::Name) => {
                        name = l[value_start..i].to_string();
                        has_colon = true;
                        value_start = i + 1;
                        stage = Stage::Value;
                    }
                    (b':', Stage::Param) if l.as_bytes()[i.saturating_sub(1)] != b'\\' => {
                        el.params.push(l[value_start..i].to_string());
                        has_colon = true;
                        value_start = i + 1;
                        stage = Stage::Value;
                    }
                    _ => {}
                }
            }
            if !has_colon {
                return Err(Error::new(format!(
                    "Error while parsing vcard: error at line {}, no colon. {:?}",
                    l, el
                ))
                .set_kind(ErrorKind::ValueError));
            }
            if name.is_empty() {
                return Err(Error::new(format!(
                    "Error while parsing vcard: error at line {}, no name for content line. {:?}",
                    l, el
                ))
                .set_kind(ErrorKind::ValueError));
            }
            el.value = l[value_start..].replace("\\:", ":");
            ret.insert(name, el);
        }
        Ok(VCard(ret, std::marker::PhantomData::<*const VCardVersion4>))
    }
}

impl<V: VCardVersion> TryInto<Card> for VCard<V> {
    type Error = crate::error::Error;

    fn try_into(mut self) -> crate::error::Result<Card> {
        let mut card = Card::new();
        card.set_id(CardId::Hash({
            let mut hasher = std::collections::hash_map::DefaultHasher::new();
            if let Some(val) = self.0.get("FN") {
                hasher.write(val.value.as_bytes());
            }
            if let Some(val) = self.0.get("N") {
                hasher.write(val.value.as_bytes());
            }
            if let Some(val) = self.0.get("EMAIL") {
                hasher.write(val.value.as_bytes());
            }
            hasher.finish()
        }));
        if let Some(val) = self.0.remove("FN") {
            card.set_name(val.value);
        } else {
            return Err(Error::new("FN entry missing in VCard.").set_kind(ErrorKind::ValueError));
        }
        if let Some(val) = self.0.remove("NICKNAME") {
            card.set_additionalname(val.value);
        }
        if let Some(val) = self.0.remove("BDAY") {
            /* 4.3.4.  DATE-AND-OR-TIME

            Either a DATE-TIME, a DATE, or a TIME value.  To allow unambiguous
            interpretation, a stand-alone TIME value is always preceded by a "T".

            Examples for "date-and-or-time":

                      19961022T140000
                      --1022T1400
                      ---22T14
                      19850412
                      1985-04
                      1985
                      --0412
                      ---12
                      T102200
                      T1022
                      T10
                      T-2200
                      T--00
                      T102200Z
                      T102200-0800
                      */
            card.birthday =
                crate::utils::datetime::timestamp_from_string(val.value.as_str(), "%Y%m%d\0")
                    .unwrap_or_default();
        }
        if let Some(val) = self.0.remove("EMAIL") {
            card.set_email(val.value);
        }
        if let Some(val) = self.0.remove("URL") {
            card.set_url(val.value);
        }
        if let Some(val) = self.0.remove("KEY") {
            card.set_key(val.value);
        }
        for (k, v) in self.0.into_iter() {
            if k.eq_ignore_ascii_case("VERSION") || k.eq_ignore_ascii_case("N") {
                continue;
            }
            card.set_extra_property(&k, v.value);
        }

        Ok(card)
    }
}

fn parse_card<'a>() -> impl Parser<'a, Vec<&'a str>> {
    move |input| {
        one_or_more(prefix(
            peek(match_literal_anycase(HEADER)),
            take_until(match_literal_anycase(FOOTER)),
        ))
        .parse(input)
    }
}

#[test]
fn test_load_cards() {
    /*
    let mut contents = String::with_capacity(256);
    let p = &std::path::Path::new("/tmp/contacts.vcf");
    use std::io::Read;
    contents.clear();
    std::fs::File::open(&p)
        .unwrap()
        .read_to_string(&mut contents)
        .unwrap();
    for s in parse_card().parse(contents.as_str()).unwrap().1 {
        println!("");
        println!("{}", s);
        println!("{:?}", CardDeserializer::try_from_str(s));
        println!("");
    }
    */
}

pub fn load_cards(p: &std::path::Path) -> Result<Vec<Card>> {
    let vcf_dir = std::fs::read_dir(p);
    let mut ret: Vec<Result<_>> = Vec::new();
    let mut is_any_valid = false;
    if vcf_dir.is_ok() {
        let mut contents = String::with_capacity(256);
        for f in vcf_dir? {
            if f.is_err() {
                continue;
            }
            let f = f?.path();
            if f.is_file() {
                use std::io::Read;
                contents.clear();
                std::fs::File::open(&f)?.read_to_string(&mut contents)?;
                match parse_card().parse(contents.as_str()) {
                    Ok((_, c)) => {
                        for s in c {
                            ret.push(
                                CardDeserializer::try_from_str(s)
                                    .and_then(TryInto::try_into)
                                    .map(|mut card| {
                                        Card::set_external_resource(&mut card, true);
                                        is_any_valid = true;
                                        card
                                    }),
                            );
                        }
                    }
                    Err(err) => {
                        log::warn!("Could not parse vcard from {}: {}", f.display(), err);
                    }
                }
            }
        }
    }
    for c in &ret {
        if c.is_err() {
            debug!(&c);
        }
    }
    if is_any_valid {
        ret.retain(Result::is_ok);
    }
    ret.into_iter().collect::<Result<Vec<Card>>>()
}

#[test]
fn test_card() {
    let j = "BEGIN:VCARD\r\nVERSION:4.0\r\nN:Gump;Forrest;;Mr.;\r\nFN:Forrest Gump\r\nORG:Bubba Gump Shrimp Co.\r\nTITLE:Shrimp Man\r\nPHOTO;MEDIATYPE=image/gif:http://www.example.com/dir_photos/my_photo.gif\r\nTEL;TYPE=work,voice;VALUE=uri:tel:+1-111-555-1212\r\nTEL;TYPE=home,voice;VALUE=uri:tel:+1-404-555-1212\r\nADR;TYPE=WORK;PREF=1;LABEL=\"100 Waters Edge\\nBaytown\\, LA 30314\\nUnited States of America\":;;100 Waters Edge;Baytown;LA;30314;United States of America\r\nADR;TYPE=HOME;LABEL=\"42 Plantation St.\\nBaytown\\, LA 30314\\nUnited States of America\":;;42 Plantation St.;Baytown;LA;30314;United States of America\r\nEMAIL:forrestgump@example.com\r\nREV:20080424T195243Z\r\nx-qq:21588891\r\nEND:VCARD\r\n";
    println!(
        "results = {:#?}",
        CardDeserializer::try_from_str(j).unwrap()
    );
    let j = "BEGIN:VCARD\nVERSION:4.0\nN:Gump;Forrest;;Mr.;\nFN:Forrest Gump\nORG:Bubba Gump Shrimp Co.\nTITLE:Shrimp Man\nPHOTO;MEDIATYPE=image/gif:http://www.example.com/dir_photos/my_photo.gif\nTEL;TYPE=work,voice;VALUE=uri:tel:+1-111-555-1212\nTEL;TYPE=home,voice;VALUE=uri:tel:+1-404-555-1212\nADR;TYPE=WORK;PREF=1;LABEL=\"100 Waters Edge\\nBaytown\\, LA 30314\\nUnited States of America\":;;100 Waters Edge;Baytown;LA;30314;United States of America\nADR;TYPE=HOME;LABEL=\"42 Plantation St.\\nBaytown\\, LA 30314\\nUnited States of America\":;;42 Plantation St.;Baytown;LA;30314;United States of America\nEMAIL:forrestgump@example.com\nREV:20080424T195243Z\nx-qq:21588891\nEND:VCARD\n";
    println!(
        "results = {:#?}",
        CardDeserializer::try_from_str(j).unwrap()
    );
}