import XCTest
@testable import MealMood

final class AutocompleteEngineTests: XCTestCase {

    func testValidateDropRejectsConsecutiveTag() {
        let tag = Tag(
            name: "Carne",
            nameEN: "Meat",
            color: "#E74C3C",
            maxPerWeek: nil,
            noConsecutive: true,
            noDuplicateInDay: false
        )

        let dishA = Dish(name: "Pollo", tagIds: [tag.id])
        let dishB = Dish(name: "Ternera", tagIds: [tag.id])

        let plan = WeekPlan(weekStartDate: Date().startOfWeek())
        let mondayDinner = MealSlot(dayOfWeek: 0, mealType: MealType.dinner.rawValue, dishId: dishA.id)
        let tuesdayDinner = MealSlot(dayOfWeek: 1, mealType: MealType.dinner.rawValue, dishId: nil)
        plan.slotList = [mondayDinner, tuesdayDinner]

        let isValid = AutocompleteEngine.validateDrop(
            dish: dishB,
            slot: tuesdayDinner,
            plan: plan,
            allTags: [tag],
            allDishes: [dishA, dishB]
        )

        XCTAssertFalse(isValid)
    }

    func testAutocompleteLeavesSlotEmptyWhenMaxPerWeekReached() {
        let tag = Tag(
            name: "Pescado",
            nameEN: "Fish",
            color: "#3498DB",
            maxPerWeek: 1,
            noConsecutive: false,
            noDuplicateInDay: false
        )

        let fishDish = Dish(name: "Salmon", tagIds: [tag.id])
        let plan = WeekPlan(weekStartDate: Date().startOfWeek())

        let mondayDinner = MealSlot(dayOfWeek: 0, mealType: MealType.dinner.rawValue, dishId: fishDish.id)
        let tuesdayDinner = MealSlot(dayOfWeek: 1, mealType: MealType.dinner.rawValue, dishId: nil)
        plan.slotList = [mondayDinner, tuesdayDinner]

        let result = AutocompleteEngine.autocomplete(
            emptySlots: [tuesdayDinner],
            currentPlan: plan,
            allDishes: [fishDish],
            allTags: [tag]
        )

        XCTAssertEqual(result.unfilledCount, 1)
        XCTAssertNil(tuesdayDinner.dishId)
    }

    func testDishStableSortRemainsConsistentAfterDeletion() {
        let base = Date()
        let oldest = Dish(id: UUID(uuidString: "00000000-0000-0000-0000-000000000001")!, name: "Old", createdAt: base.addingTimeInterval(-60))
        let newest = Dish(id: UUID(uuidString: "00000000-0000-0000-0000-000000000002")!, name: "New", createdAt: base)
        let middle = Dish(id: UUID(uuidString: "00000000-0000-0000-0000-000000000003")!, name: "Middle", createdAt: base.addingTimeInterval(-30))

        let initial = Dish.stableSortedForDisplay([oldest, newest, middle]).map(\.id)
        XCTAssertEqual(initial, [newest.id, middle.id, oldest.id])

        let afterDeletion = Dish.stableSortedForDisplay([newest, oldest]).map(\.id)
        XCTAssertEqual(afterDeletion, [newest.id, oldest.id])
    }

    func testPreferredDuplicateSlotKeepsAssignedDish() {
        let duplicateWithDish = MealSlot(dayOfWeek: 0, mealType: MealType.dinner.rawValue, dishId: UUID())
        let duplicateWithoutDish = MealSlot(dayOfWeek: 0, mealType: MealType.dinner.rawValue, dishId: nil)

        let preferred = MealSlot.preferredForDuplicateResolution([duplicateWithoutDish, duplicateWithDish])
        XCTAssertEqual(preferred.id, duplicateWithDish.id)
    }
}

/// The violations panel explains *which* rule is broken; these cover the
/// reason detection that feeds it.
final class ViolationReasonsTests: XCTestCase {

    private func makePlan(slots: [(day: Int, meal: String, dishId: UUID?)]) -> WeekPlan {
        let plan = WeekPlan(weekStartDate: Date().startOfWeek())
        for s in slots {
            let slot = MealSlot(dayOfWeek: s.day, mealType: s.meal, dishId: s.dishId)
            slot.weekPlan = plan
            plan.slotList.append(slot)
        }
        return plan
    }

    func testMaxPerWeekExceededIsReported() {
        let tag = Tag(name: "Pasta", color: "#FF0000", maxPerWeek: 1)
        let dish = Dish(name: "Espaguetis", tagIds: [tag.id])
        let other = Dish(name: "Macarrones", tagIds: [tag.id])
        let plan = makePlan(slots: [(0, "dinner", dish.id), (1, "dinner", other.id)])
        let slot = plan.slotList[0]

        let reasons = AutocompleteEngine.reasons(
            dish: dish, slot: slot, plan: plan,
            tagMap: [tag.id: tag], dishMap: [dish.id: dish, other.id: other]
        )
        XCTAssertTrue(reasons.contains { $0.kind == .maxPerWeek && $0.limit == 1 },
                      "Two pasta dishes with max 1/week must report maxPerWeek")
    }

    func testMealTypeRestrictionIsReported() {
        let tag = Tag(name: "Ligero", color: "#00FF00", mealTypeRestriction: "dinner")
        let dish = Dish(name: "Ensalada", tagIds: [tag.id])
        let plan = makePlan(slots: [(0, "lunch", dish.id)])

        let reasons = AutocompleteEngine.reasons(
            dish: dish, slot: plan.slotList[0], plan: plan,
            tagMap: [tag.id: tag], dishMap: [dish.id: dish]
        )
        XCTAssertTrue(reasons.contains { $0.kind == .mealTypeOnly && $0.restriction == "dinner" },
                      "A dinner-only tag placed at lunch must report mealTypeOnly")
    }

    func testRepeatedDishInWeekIsReported() {
        let dish = Dish(name: "Tortilla")
        let plan = makePlan(slots: [(0, "dinner", dish.id), (3, "dinner", dish.id)])

        let reasons = AutocompleteEngine.reasons(
            dish: dish, slot: plan.slotList[0], plan: plan,
            tagMap: [:], dishMap: [dish.id: dish]
        )
        XCTAssertTrue(reasons.contains { $0.kind == .repeatedInWeek })
    }

    func testCompliantDishHasNoReasons() {
        let tag = Tag(name: "Pescado", color: "#0000FF", maxPerWeek: 2)
        let dish = Dish(name: "Merluza", tagIds: [tag.id])
        let plan = makePlan(slots: [(0, "dinner", dish.id)])

        let reasons = AutocompleteEngine.reasons(
            dish: dish, slot: plan.slotList[0], plan: plan,
            tagMap: [tag.id: tag], dishMap: [dish.id: dish]
        )
        XCTAssertTrue(reasons.isEmpty, "A dish within its limits must not report violations")
    }
}

/// Violations come from the current plan, not from a stored flag.
final class ViolationFreshnessTests: XCTestCase {

    private func plan(_ slots: [MealSlot]) -> WeekPlan {
        let p = WeekPlan(weekStartDate: Date().startOfWeek())
        slots.forEach { $0.weekPlan = p; p.slotList.append($0) }
        return p
    }

    /// The bug from the screenshot: a meal flagged long ago, whose conflict is
    /// already gone, was still listed — with nothing to explain.
    func testStaleFlagIsNotReported() {
        let dish = Dish(name: "Ensalada campera")
        let slot = MealSlot(dayOfWeek: 0, mealType: "dinner", dishId: dish.id)
        slot.isRuleOverridden = true          // marca antigua
        let week = plan([slot])

        let violations = AutocompleteEngine.findViolations(plan: week, allDishes: [dish], allTags: [])
        XCTAssertTrue(violations.isEmpty, "A stale flag with no current conflict must not be listed")
    }

    /// And the opposite: a rule tightened after planning must be caught even
    /// though no flag was ever set.
    func testRuleEditedAfterPlanningIsCaught() {
        let tag = Tag(name: "Pasta", color: "#FF0000", maxPerWeek: 1)
        let a = Dish(name: "Espaguetis", tagIds: [tag.id])
        let b = Dish(name: "Macarrones", tagIds: [tag.id])
        let week = plan([
            MealSlot(dayOfWeek: 0, mealType: "dinner", dishId: a.id),
            MealSlot(dayOfWeek: 1, mealType: "dinner", dishId: b.id)
        ])

        let violations = AutocompleteEngine.findViolations(plan: week, allDishes: [a, b], allTags: [tag])
        XCTAssertEqual(violations.count, 2, "Both pasta meals exceed max 1/week")
        XCTAssertTrue(violations.allSatisfy { !$0.reasons.isEmpty }, "Every listed violation must explain itself")
    }

    func testIgnoredSlotStaysHidden() {
        let dish = Dish(name: "Tortilla")
        let s1 = MealSlot(dayOfWeek: 0, mealType: "dinner", dishId: dish.id)
        let s2 = MealSlot(dayOfWeek: 3, mealType: "dinner", dishId: dish.id)
        s1.isRuleIgnored = true
        let week = plan([s1, s2])

        let violations = AutocompleteEngine.findViolations(plan: week, allDishes: [dish], allTags: [])
        XCTAssertEqual(violations.map(\.slotId), [s2.id], "The dismissed slot must not come back")
    }
}