#[derive(Clone, Debug, Default)]
pub struct Passport {
	// "byr": birth_year
	pub birth_year: Option<String>,
	// "iyr": issue_year
	pub issue_year: Option<String>,
	// "eyr": expiration_year
	pub expiration_year: Option<String>,
	// "hgt": height
	pub height: Option<String>,
	// "hcl": hair_color
	pub hair_color: Option<String>,
	// "ecl": eye_color
	pub eye_color: Option<String>,
	// "pid": passport_id
	pub passport_id: Option<String>,
	// "cid": country_id
	pub country_id: Option<String>,
}

impl Passport {
	pub fn parse(text: &str) -> Self {
		let mut result = Self::default();
		for token in text.split_whitespace() {
			let colon = token.find(':').expect("missing separator");
			let key = &token[..colon];
			let value = &token[colon+1..];
			match key {
				"byr" => result.birth_year = Some(value.into()),
				"iyr" => result.issue_year = Some(value.into()),
				"eyr" => result.expiration_year = Some(value.into()),
				"hgt" => result.height = Some(value.into()),
				"hcl" => result.hair_color = Some(value.into()),
				"ecl" => result.eye_color = Some(value.into()),
				"pid" => result.passport_id = Some(value.into()),
				"cid" => result.country_id = Some(value.into()),
				_ => panic!("unknown field {:?}", key),
			}
		}
		result
	}

	pub fn parse_list(text: &str) -> Vec<Self> {
		text.split("\n\n").map(Self::parse).collect()
	}

	pub fn require_all_but_country_id(&self) -> bool {
		self.birth_year.is_some() &
		self.issue_year.is_some() &
		self.expiration_year.is_some() &
		self.height.is_some() &
		self.hair_color.is_some() &
		self.eye_color.is_some() &
		self.passport_id.is_some()
	}

	fn _valid(&self) -> Option<()> {
		let birth_year = self.birth_year.as_ref()?.parse::<u16>().ok()?;
		if birth_year < 1920 || birth_year > 2002 {
			return None;
		}
		let issue_year = self.issue_year.as_ref()?.parse::<u16>().ok()?;
		if issue_year < 2010 || issue_year > 2020 {
			return None;
		}
		let expiration_year = self.expiration_year.as_ref()?.parse::<u16>().ok()?;
		if expiration_year < 2020 || expiration_year > 2030 {
			return None;
		}
		let height = self.height.as_ref()?;
		if height.ends_with("cm") {
			let height = height[..height.len() - 2].parse::<u16>().ok()?;
			if height < 150 || height > 193 {
				return None;
			}
		} else if height.ends_with("in") {
			let height = height[..height.len() - 2].parse::<u16>().ok()?;
			if height < 59 || height > 76 {
				return None;
			}
		} else {
			return None;
		}
		let hair_color = self.hair_color.as_ref()?;
		if !hair_color.starts_with("#") || hair_color.len() != 7 {
			return None;
		}
		if !hair_color[1..].chars().all(|c| (c >= '0' && c <= '9') || (c >= 'a' && c <= 'f')) {
			return None;
		}
		let eye_color = self.eye_color.as_ref()?;
		match eye_color.as_str() {
			"amb"|"blu"|"brn"|"gry"|"grn"|"hzl"|"oth" => (),
			_ => return None,
		}
		let passport_id = self.passport_id.as_ref()?;
		if passport_id.len() != 9 || !passport_id.chars().all(|c| c.is_ascii_digit()) {
			return None;
		}
		Some(())
	}

	pub fn valid(&self) -> bool {
		self._valid().is_some()
	}
}