// 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::{self, Client},
    error::Error,
};
use serde::{Serialize, Serializer};
use std::collections::BTreeMap;


/// Data type for values that an Item can hold.
pub enum ItemData<'a> {
    /// A single value, either textual or numeric.
    Value(&'a str),
}

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

impl<'a> Serialize for ItemData<'a> {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: Serializer
    {
        match &self {
            ItemData::Value(s) => s.serialize(serializer),
        }
    }
}

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

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

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

    /// 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
    }

    /// Create the item by poting it to the server
    pub fn create(&self) -> Result<String, Error> {
        if self.files.is_empty() {
            self.client.post_data(client::ZOTAPI_ITEM_UPDATE_PATH, &self.data)
        }
        else {
            self.client.post_multipart(client::ZOTAPI_ITEM_UPDATE_PATH, &self.data, &self.files)
        }
    }
}