//! ## Store
//!
//! `Store` is the module which provides the Context Storage.
//! The context storage is a storage indeed which is shared between the activities thanks to the context
//! The storage can be used to store any values which should be cached or shared between activities

/*
*
*   Copyright (C) 2020-2021 Christian Visintin - christian.visintin1997@gmail.com
*
* 	This file is part of "TermSCP"
*
*   TermSCP 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.
*
*   TermSCP 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 TermSCP.  If not, see <http://www.gnu.org/licenses/>.
*
*/

use std::collections::HashMap;

// -- store state

/// ## StoreState
///
/// Store state describes a value in the store
#[allow(dead_code)]
enum StoreState {
    Str(String),     // String
    Signed(isize),   // Signed number
    Unsigned(usize), // Unsigned number
    Float(f64),      // Floating point number
    Boolean(bool),   // Boolean value
    Flag,            // Empty value; used to work as a Flag (set unset)
}

// -- store

/// ## Store
///
/// Store represent the context store
/// The store is a key-value hash map. Each key must be unique
/// To each key a `StoreState` is assigned
pub(crate) struct Store {
    store: HashMap<String, StoreState>,
}

#[allow(dead_code)]
impl Store {
    /// ### init
    ///
    /// Initialize a new Store
    pub fn init() -> Self {
        Store {
            store: HashMap::new(),
        }
    }

    // -- getters
    /// ### get_string
    ///
    /// Get string from store
    pub fn get_string(&self, key: &str) -> Option<&str> {
        match self.store.get(key) {
            Some(StoreState::Str(s)) => Some(s.as_str()),
            _ => None,
        }
    }

    /// ### get_signed
    ///
    /// Get signed from store
    pub fn get_signed(&self, key: &str) -> Option<isize> {
        match self.store.get(key) {
            Some(StoreState::Signed(i)) => Some(*i),
            _ => None,
        }
    }

    /// ### get_unsigned
    ///
    /// Get unsigned from store
    pub fn get_unsigned(&self, key: &str) -> Option<usize> {
        match self.store.get(key) {
            Some(StoreState::Unsigned(u)) => Some(*u),
            _ => None,
        }
    }

    /// ### get_float
    ///
    /// get float from store
    pub fn get_float(&self, key: &str) -> Option<f64> {
        match self.store.get(key) {
            Some(StoreState::Float(f)) => Some(*f),
            _ => None,
        }
    }

    /// ### get_boolean
    ///
    /// get boolean from store
    pub fn get_boolean(&self, key: &str) -> Option<bool> {
        match self.store.get(key) {
            Some(StoreState::Boolean(b)) => Some(*b),
            _ => None,
        }
    }

    /// ### isset
    ///
    /// Check if a state is set in the store
    pub fn isset(&self, key: &str) -> bool {
        self.store.get(key).is_some()
    }

    // -- setters

    /// ### set_string
    ///
    /// Set string into the store
    pub fn set_string(&mut self, key: &str, val: String) {
        self.store.insert(key.to_string(), StoreState::Str(val));
    }

    /// ### set_signed
    ///
    /// Set signed number
    pub fn set_signed(&mut self, key: &str, val: isize) {
        self.store.insert(key.to_string(), StoreState::Signed(val));
    }

    /// ### set_signed
    ///
    /// Set unsigned number
    pub fn set_unsigned(&mut self, key: &str, val: usize) {
        self.store
            .insert(key.to_string(), StoreState::Unsigned(val));
    }

    /// ### set_float
    ///
    /// Set floating point number
    pub fn set_float(&mut self, key: &str, val: f64) {
        self.store.insert(key.to_string(), StoreState::Float(val));
    }

    /// ### set_boolean
    ///
    /// Set boolean
    pub fn set_boolean(&mut self, key: &str, val: bool) {
        self.store.insert(key.to_string(), StoreState::Boolean(val));
    }

    /// ### set
    ///
    /// Set a key as a flag; has no value
    pub fn set(&mut self, key: &str) {
        self.store.insert(key.to_string(), StoreState::Flag);
    }
}

#[cfg(test)]
mod tests {

    use super::*;

    #[test]
    fn test_ui_store() {
        // Create store
        let mut store: Store = Store::init();
        // Test string
        store.set_string("test", String::from("hello"));
        assert_eq!(*store.get_string("test").as_ref().unwrap(), "hello");
        // Test isize
        store.set_signed("number", 3005);
        assert_eq!(store.get_signed("number").unwrap(), 3005);
        store.set_signed("number", -123);
        assert_eq!(store.get_signed("number").unwrap(), -123);
        // Test usize
        store.set_unsigned("unumber", 1024);
        assert_eq!(store.get_unsigned("unumber").unwrap(), 1024);
        // Test float
        store.set_float("float", 3.33);
        assert_eq!(store.get_float("float").unwrap(), 3.33);
        // Test boolean
        store.set_boolean("bool", true);
        assert_eq!(store.get_boolean("bool").unwrap(), true);
        // Test flag
        store.set("myflag");
        assert_eq!(store.isset("myflag"), true);
        // Test unexisting
        assert!(store.get_boolean("unexisting-key").is_none());
        assert!(store.get_float("unexisting-key").is_none());
        assert!(store.get_signed("unexisting-key").is_none());
        assert!(store.get_signed("unexisting-key").is_none());
        assert!(store.get_string("unexisting-key").is_none());
        assert!(store.get_unsigned("unexisting-key").is_none());
    }
}