//! The weekly menu planner
//!
extern crate cookbook;
extern crate planner;

use self::cookbook::*;
use self::cookbook::models::Recipe;
use self::planner::solver::{Variables, Domain, Problem, Constraint};

/// We want a mapping of the week meals (matin, midi, soir)
///  Breakfast => RecipeCategory::Breakfast
///  Lunch => RecipeCategory::MainCourse
///  Dinner => RecipeCategory::MainCourse
type Day = String;

enum Meals {
    Breakfast(Day),
    Lunch(Day),
    Dinner(Day)
}

impl Into<String> for Meals {
    fn into(self) -> String {
        match self {
            Meals::Breakfast(d) => format!("{}_Breakfast", d),
            Meals::Lunch(d) => format!("{}_Lunch", d),
            Meals::Dinner(d) => format!("{}_Dinner", d),
        }
    }
}
/// associated with filters for Domain, depending on recipes RecipeCategory
enum RecipeCategory {
    Breakfast,
    MainCourse
}
/// It may also contains an initial value for each variable
fn generate_variables<V>(domain: &Domain<V>) -> Vec<(String, &Domain<V>, Option<&V>)> {
    let mut vars = Vec::new();
    for day in &["Lundi", "Mardi", "Mercredi"] {
       vars.push((Meals::Lunch(day.to_string()).into(), domain, None));
       vars.push((Meals::Dinner(day.to_string()).into(), domain, None));
    }
    vars
}

fn ingredients_contains<'a>(assign: &Variables<'a,Recipe>) -> bool {
       assign.get("Lundi_Lunch").unwrap().unwrap().ingredients.contains("Patates")
    && !assign.get("Mardi_Lunch").unwrap().unwrap().ingredients.contains("Patates")
}

fn get_planning_all_results() -> String {
    let conn = establish_connection();
    let possible_values = recipes::load_all(&conn);
    let domain = Domain::new(possible_values);
    let mut problem = Problem::build();
    for (var, dom, ini) in generate_variables(&domain) {
        problem = problem.add_variable(var, dom, ini);
    }
    let mut problem = problem.add_constraint(ingredients_contains)
                             .finish();
    let results = problem.solve_all();
    format!("{:#?}\nTotal = {}", &results.first(), results.len())
}

fn main() {
    println!("{}", get_planning_all_results());
}