// zotapi - Rust wrapper for Sot API as implemented by Hubzilla
// Copyright (C) 2018  Harald Eilertsen <haraldei@anduin.net>
//
// This program 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.
//
// This program 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 this program.  If not, see <https://www.gnu.org/licenses/>.

use crate::{client::Client, error::Error};
use reqwest::{
    self,
    header::{CONTENT_TYPE},
};
use serde::{Deserialize, Serialize};
use std::collections::BTreeMap;
use std::fs::File;
use std::io::Read;

/// Data type for values that an Item can hold.
#[derive(Debug, Serialize)]
#[serde(untagged)]
pub enum ItemData<'a> {
    /// A single value, either textual or numeric.
    Value(&'a str),

    /// A list ov values.
    List(Vec<&'a str>),
}

impl<'a> From<&'a str> for ItemData<'a> {
    fn from(orig: &'a str) -> ItemData<'a> {
        ItemData::Value(orig)
    }
}

impl<'a> ToString for ItemData<'a> {
    fn to_string(&self) -> String {
        match &self {
            ItemData::Value(s) => s.to_string(),
            ItemData::List(v) => v.join(","),
        }
    }
}

impl<'a> ItemData<'a> {
    /// Push a new value into
    pub fn push(&mut self, value: &'a str) {
        match self {
            ItemData::Value(_) => std::panic!("Pushing to a simple value is not allowed."),
            ItemData::List(v) => v.push(value),
        };
    }
}

#[test]
fn convert_itemdata_list_to_a_string() {
    let l = ItemData::List(vec!["one", "two", "everything"]);
    assert_eq!(l.to_string(), "one,two,everything");
}

#[test]
fn convert_itemdata_list_with_one_member_to_a_string() {
    let l = ItemData::List(vec!["one"]);
    assert_eq!(l.to_string(), "one");
}

#[derive(Debug, Deserialize)]
pub struct ItemCreatedResponse {
    pub success: bool,
    pub item_id: u32,
}

/// A structure to help you create an item in a declarative way.
///
/// Typical usage:
///
/// ```no_run
/// # async {
/// let client = zotapi::client("https://myhub.com", "mychannel", "mypw");
/// let new_post = zotapi::item()
///     .title("A title")
///     .body("The body of the post")
///     .file("/my/photo.jpg")
///     .create(&client)
///     .await?;
/// # Ok::<(), zotapi::Error>(())
/// # };
/// ```
/// ```
#[derive(Debug)]
pub struct ItemBuilder<'a> {
    data: BTreeMap<&'a str, ItemData<'a>>,
    files: Vec<&'a str>,
}

pub fn item<'a>() -> ItemBuilder<'a> {
    ItemBuilder {
        data: BTreeMap::new(),
        files: vec![],
    }
}

impl<'a> ItemBuilder<'a> {
    /// Add a title to the post
    pub fn title(&mut self, text: &'a str) -> &mut ItemBuilder<'a> {
        self.data.insert("title", ItemData::Value(text));
        self
    }

    /// Add the body of the post
    pub fn body(&mut self, text: &'a str) -> &mut ItemBuilder<'a> {
        self.data.insert("body", ItemData::Value(text));
        self
    }

    /// Add a file attachment to the post
    pub fn file(&mut self, fname: &'a str) -> &mut ItemBuilder<'a> {
        self.files.push(fname);
        self
    }

    /// Set groups allowed to access item
    pub fn group_allow(&mut self, group: &'a str) -> &mut ItemBuilder<'a> {
        let groups_allow = self
            .data
            .entry("groups_allow")
            .or_insert(ItemData::List(Vec::<&str>::new()));

        groups_allow.push(group);
        self
    }

    /// Create the item by poting it to the server
    pub async fn create(&self, client: &Client) -> Result<ItemCreatedResponse, Error> {
        dbg!(self);
        let mut req = client.post("item/update");

        if self.files.is_empty() {
            req = req
                .header(CONTENT_TYPE, "application/x-www-form-urlencoded")
                .body(serde_qs::to_string(&self.data)?)
        } else {
            let mut form = reqwest::multipart::Form::new();

            for (key, value) in self.data.iter() {
                form = form.text(key.to_string(), value.to_string());
            }

            for f in self.files.iter() {
                let mut pdata = vec![];
                let path = std::path::Path::new(f);
                File::open(path)?.read_to_end(&mut pdata)?;

                let filename = String::from(path.file_name().unwrap().to_str().unwrap());
                let p = reqwest::multipart::Part::bytes(pdata)
                    .file_name(filename);
                form = form.part("media", p);
            }

            req = req.multipart(form)
        }

        Ok(serde_json::from_str(&req.send().await?.text().await?)?)
    }
}

#[test]
fn add_group_to_list_of_groups_allowed() {
    let mut item = item();
    item.group_allow("test");
    match item.data.get("groups_allow") {
        Some(ItemData::List(v)) => assert_eq!(v.len(), 1),
        Some(ItemData::Value(s)) => assert!(false, "Expected a list, found value: {}", s),
        None => assert!(false, "List not found!"),
    };
}