#[derive(Copy, Clone, PartialEq, Debug)]
pub enum Status
{
	Safe,
	Unsafe,
	Unknown,
}

#[derive(Clone, Debug)]
pub struct Report
{
	levels: Vec<i32>,
	status: Status,
	enable_dampener: bool,
	dampen_count: i32,
}

impl Report
{
	pub fn new(lvls: Vec<i32>, enable_dampener: bool) -> Report
	{
		Report { levels: lvls , status: Status::Unknown, enable_dampener, dampen_count: 0 }
	}

	// SAFTY RULES:
    // 		The levels are either all increasing or all decreasing.
    // 		Any two adjacent levels differ by at least one and at most three.

	pub fn analyze(self: &mut Report, enable_debug_prints: bool) -> Status
	{
		let mut prev_direction = 0;
		let mut i = 0;
		while i < self.levels.len() - 1 // Don't process the last level value	
		{
			let diff = self.levels[i] - self.levels[i + 1];
			let this_direction = if diff > 0 { 1 } else if diff < 0 { -1 } else { 0 };

			// diff check
			let diff = diff.abs();
			if diff > 3 || diff < 1
			{
				if self.dampen_level(i + 1, enable_debug_prints)
				{
					i = 0;
					continue;
				}

				if enable_debug_prints
				{
					println!("Day 2 DEBUG: Report ({:#?}) is unsafe due to invalid value gap ({}): {} to {}", self.levels, diff, self.levels[i], self.levels[i + 1])
				}
				self.status = Status::Unsafe;
				return self.status;
			}

			// increase/decrease check
			if 0 == prev_direction
			{
				prev_direction = this_direction
			}		
			else
			{
				if prev_direction != this_direction
				{
					if self.dampen_level(i, enable_debug_prints)
					{
						i = 0;
						continue;
					}

					if enable_debug_prints
					{
						println!("Day 2 DEBUG: Report ({:#?}) is unsafe due to increase/decrease rule violation: {} to {}", self.levels, self.levels[i], self.levels[i + 1])
					}
					self.status = Status::Unsafe;
					return self.status;
				}
			}

			i += 1;
		}
		
		self.status = Status::Safe;
		return self.status;
	}

	fn check_levels(self: &mut Report, enable_debug_prints: bool) -> Status
	{
		Status::Unknown
	}

	fn dampen_level(self: &mut Report, at: usize, do_debug_prints: bool) -> bool
	{
		if !self.enable_dampener
		{
			return false;
		}

		if do_debug_prints
		{
			println!("Day 2 DEBUG: Bad level detected in report ({:#?}), using dampener to remove level: {}", self.levels, self.levels[at]);
		}

		self.levels.remove(at);
		self.enable_dampener = false;
		self.dampen_count += 1;

		if self.dampen_count > 1
		{
			panic!("Day 2 ERROR: Dampener used more than once! usage: {}", self.dampen_count);
		}

		return true;
	}
}