use RoaringBitmap;

use super::util;
use super::container::Container;

impl RoaringBitmap {
    /// Creates an empty `RoaringBitmap`.
    ///
    /// # Examples
    ///
    /// ```rust
    /// use roaring::RoaringBitmap;
    /// let mut rb = RoaringBitmap::new();
    /// ```
    pub fn new() -> RoaringBitmap {
        RoaringBitmap { containers: Vec::new() }
    }

    /// Adds a value to the set. Returns `true` if the value was not already present in the set.
    ///
    /// # Examples
    ///
    /// ```rust
    /// use roaring::RoaringBitmap;
    ///
    /// let mut rb = RoaringBitmap::new();
    /// assert_eq!(rb.insert(3), true);
    /// assert_eq!(rb.insert(3), false);
    /// assert_eq!(rb.contains(3), true);
    /// ```
    pub fn insert(&mut self, value: u32) -> bool {
        let (key, index) = util::split(value);
        let container = match self.containers.binary_search_by_key(&key, |c| c.key) {
            Ok(loc) => &mut self.containers[loc],
            Err(loc) => {
                self.containers.insert(loc, Container::new(key));
                &mut self.containers[loc]
            },
        };
        container.insert(index)
    }

    /// Removes a value from the set. Returns `true` if the value was present in the set.
    ///
    /// # Examples
    ///
    /// ```rust
    /// use roaring::RoaringBitmap;
    ///
    /// let mut rb = RoaringBitmap::new();
    /// rb.insert(3);
    /// assert_eq!(rb.remove(3), true);
    /// assert_eq!(rb.remove(3), false);
    /// assert_eq!(rb.contains(3), false);
    /// ```
    pub fn remove(&mut self, value: u32) -> bool {
        let (key, index) = util::split(value);
        match self.containers.binary_search_by_key(&key, |c| c.key) {
            Ok(loc) => {
                if self.containers[loc].remove(index) {
                    if self.containers[loc].len == 0 {
                        self.containers.remove(loc);
                    }
                    true
                } else {
                    false
                }
            }
            _ => false,
        }
    }

    /// Returns `true` if this set contains the specified integer.
    ///
    /// # Examples
    ///
    /// ```rust
    /// use roaring::RoaringBitmap;
    ///
    /// let mut rb = RoaringBitmap::new();
    /// rb.insert(1);
    /// assert_eq!(rb.contains(0), false);
    /// assert_eq!(rb.contains(1), true);
    /// assert_eq!(rb.contains(100), false);
    /// ```
    pub fn contains(&self, value: u32) -> bool {
        let (key, index) = util::split(value);
        match self.containers.binary_search_by_key(&key, |c| c.key) {
            Ok(loc) => self.containers[loc].contains(index),
            Err(_) => false,
        }
    }

    /// Clears all integers in this set.
    ///
    /// # Examples
    ///
    /// ```rust
    /// use roaring::RoaringBitmap;
    ///
    /// let mut rb = RoaringBitmap::new();
    /// rb.insert(1);
    /// assert_eq!(rb.contains(1), true);
    /// rb.clear();
    /// assert_eq!(rb.contains(1), false);
    /// ```
    pub fn clear(&mut self) {
        self.containers.clear();
    }

    /// Returns `true` if there are no integers in this set.
    ///
    /// # Examples
    ///
    /// ```rust
    /// use roaring::RoaringBitmap;
    ///
    /// let mut rb = RoaringBitmap::new();
    /// assert_eq!(rb.is_empty(), true);
    ///
    /// rb.insert(3);
    /// assert_eq!(rb.is_empty(), false);
    /// ```
    pub fn is_empty(&self) -> bool {
        self.containers.is_empty()
    }

    /// Returns the number of distinct integers added to the set.
    ///
    /// # Examples
    ///
    /// ```rust
    /// use roaring::RoaringBitmap;
    ///
    /// let mut rb = RoaringBitmap::new();
    /// assert_eq!(rb.len(), 0);
    ///
    /// rb.insert(3);
    /// assert_eq!(rb.len(), 1);
    ///
    /// rb.insert(3);
    /// rb.insert(4);
    /// assert_eq!(rb.len(), 2);
    /// ```
    pub fn len(&self) -> u64 {
        self.containers
            .iter()
            .map(|container| container.len)
            .sum()
    }

    /// Returns the minimum value in the set (if the set is non-empty).
    ///
    /// # Examples
    ///
    /// ```rust
    /// use roaring::RoaringBitmap;
    ///
    /// let mut rb = RoaringBitmap::new();
    /// assert_eq!(rb.min(), None);
    ///
    /// rb.insert(3);
    /// rb.insert(4);
    /// assert_eq!(rb.min(), Some(3));
    /// ```
    pub fn min(&self) -> Option<u32> {
        self.containers.first()
            .map(|head| util::join(head.key, head.min()))
    }


    /// Returns the maximum value in the set (if the set is non-empty).
    ///
    /// # Examples
    ///
    /// ```rust
    /// use roaring::RoaringBitmap;
    ///
    /// let mut rb = RoaringBitmap::new();
    /// assert_eq!(rb.max(), None);
    ///
    /// rb.insert(3);
    /// rb.insert(4);
    /// assert_eq!(rb.max(), Some(4));
    /// ```
    pub fn max(&self) -> Option<u32> {
        self.containers.last()
            .map(|tail| util::join(tail.key, tail.max()))
    }
}

impl Default for RoaringBitmap {
    fn default() -> RoaringBitmap {
        RoaringBitmap::new()
    }
}