//
//  Bunch_O__DiceTests.swift
//  Bunch O' DiceTests
//
//  Created by Rory Hinnen on 22/2/20.
//

import Testing
@testable import Bunch_O__Dice

// MARK: - Dice Total Calculation

@Suite("Dice Total Calculation")
struct DiceTotalTests {

    // One die showing each face — a clean baseline for cutoff tests.
    func oneEach() -> Dice {
        var d = Dice()
        d.one = 1; d.two = 1; d.three = 1; d.four = 1; d.five = 1; d.six = 1
        return d
    }

    @Test("No modifier counts faces at or above cutoff")
    func totalNoModifier() {
        let d = oneEach()
        #expect(d.total(cutoff: 6, modifier: .none) == 1)
        #expect(d.total(cutoff: 5, modifier: .none) == 2)
        #expect(d.total(cutoff: 4, modifier: .none) == 3)
        #expect(d.total(cutoff: 3, modifier: .none) == 4)
        #expect(d.total(cutoff: 2, modifier: .none) == 5)
    }

    @Test("Negative modifier effectively raises cutoff by 1")
    func totalNegativeModifier() {
        let d = oneEach()
        #expect(d.total(cutoff: 5, modifier: .negative) == 1) // effectively 6+
        #expect(d.total(cutoff: 4, modifier: .negative) == 2) // effectively 5+
        #expect(d.total(cutoff: 3, modifier: .negative) == 3) // effectively 4+
        #expect(d.total(cutoff: 2, modifier: .negative) == 4) // effectively 3+
        #expect(d.total(cutoff: 1, modifier: .negative) == 5) // effectively 2+
    }

    @Test("Positive modifier effectively lowers cutoff by 1")
    func totalPositiveModifier() {
        let d = oneEach()
        #expect(d.total(cutoff: 6, modifier: .positive) == 2) // effectively 5+
        #expect(d.total(cutoff: 5, modifier: .positive) == 3) // effectively 4+
        #expect(d.total(cutoff: 4, modifier: .positive) == 4) // effectively 3+
        #expect(d.total(cutoff: 3, modifier: .positive) == 5) // effectively 2+
        #expect(d.total(cutoff: 2, modifier: .positive) == 5) // already at 2+, no further shift
    }
}

// MARK: - Armour Save Calculation

@Suite("Armour Save Calculation")
struct ArmourSaveTests {

    func oneEach() -> Dice {
        var d = Dice()
        d.one = 1; d.two = 1; d.three = 1; d.four = 1; d.five = 1; d.six = 1
        return d
    }

    @Test("Counts dice that fail the save")
    func normalSaves() {
        let d = oneEach()
        #expect(d.armour(die: 6, invulnerable: false, save: 6, armourPenetration: 0) == 5) // 1-5 fail
        #expect(d.armour(die: 6, invulnerable: false, save: 5, armourPenetration: 0) == 4) // 1-4 fail
        #expect(d.armour(die: 6, invulnerable: false, save: 4, armourPenetration: 0) == 3) // 1-3 fail
        #expect(d.armour(die: 6, invulnerable: false, save: 3, armourPenetration: 0) == 2) // 1-2 fail
        #expect(d.armour(die: 6, invulnerable: false, save: 2, armourPenetration: 0) == 1) // only 1 fails
    }

    @Test("AP reduces effective save value")
    func armourPenetration() {
        let d = oneEach()
        // 3+ save with AP 1 → effective 4+: 1-3 fail
        #expect(d.armour(die: 6, invulnerable: false, save: 3, armourPenetration: 1) == 3)
        // 3+ save with AP 2 → effective 5+: 1-4 fail
        #expect(d.armour(die: 6, invulnerable: false, save: 3, armourPenetration: 2) == 4)
    }

    @Test("Invulnerable save ignores AP")
    func invulnerableSave() {
        let d = oneEach()
        // 4++ invulnerable with heavy AP should match a plain 4+ with no AP
        let withInvuln = d.armour(die: 6, invulnerable: true, save: 4, armourPenetration: 5)
        let noAP       = d.armour(die: 6, invulnerable: false, save: 4, armourPenetration: 0)
        #expect(withInvuln == noAP)
    }
}

// MARK: - Roll Modifiers

@Suite("Roll Modifiers")
struct RollModifierTests {

    @Test("add() clamps at positive")
    func addModifier() {
        #expect(Dice.RollModifiers.negative.add() == .none)
        #expect(Dice.RollModifiers.none.add()     == .positive)
        #expect(Dice.RollModifiers.positive.add() == .positive)
    }

    @Test("remove() clamps at negative")
    func removeModifier() {
        #expect(Dice.RollModifiers.positive.remove() == .none)
        #expect(Dice.RollModifiers.none.remove()     == .negative)
        #expect(Dice.RollModifiers.negative.remove() == .negative)
    }
}

// MARK: - Wound Cutoff

@Suite("Wound Cutoff")
struct WoundCutoffTests {

    @Test("S double or more T: wound on 2+")
    func doubleStrength() {
        let roll = Roll()
        roll.strength = 10; roll.toughness = 5
        #expect(roll.woundCutoff == 2)
        roll.strength = 6; roll.toughness = 3
        #expect(roll.woundCutoff == 2)
    }

    @Test("S greater than T but less than double: wound on 3+")
    func strengthHigher() {
        let roll = Roll()
        roll.strength = 7; roll.toughness = 5
        #expect(roll.woundCutoff == 3)
        roll.strength = 4; roll.toughness = 3
        #expect(roll.woundCutoff == 3)
    }

    @Test("S equals T: wound on 4+")
    func equal() {
        let roll = Roll()
        roll.strength = 5; roll.toughness = 5
        #expect(roll.woundCutoff == 4)
        roll.strength = 3; roll.toughness = 3
        #expect(roll.woundCutoff == 4)
    }

    @Test("T greater than S but less than double: wound on 5+")
    func toughnessHigher() {
        let roll = Roll()
        roll.strength = 3; roll.toughness = 5
        #expect(roll.woundCutoff == 5)
        roll.strength = 4; roll.toughness = 5
        #expect(roll.woundCutoff == 5)
    }

    @Test("T double or more S: wound on 6+")
    func doubleToughness() {
        let roll = Roll()
        roll.strength = 2; roll.toughness = 5
        #expect(roll.woundCutoff == 6)
        roll.strength = 1; roll.toughness = 3
        #expect(roll.woundCutoff == 6)
    }
}

// MARK: - Reroll Logic

@Suite("Reroll Logic")
struct RerollTests {

    @Test("rerollBelow: no-op when no dice fall below cutoff")
    func rerollBelowNoop() {
        var d = Dice()
        d.four = 2; d.five = 3; d.six = 1
        d.rerollBelow(cutoff: 4)
        #expect(d.one   == 0)
        #expect(d.two   == 0)
        #expect(d.three == 0)
        #expect(d.four  == 2)
        #expect(d.five  == 3)
        #expect(d.six   == 1)
    }

    @Test("rerollBelow: preserves total dice count")
    func rerollBelowPreservesCount() {
        var d = Dice()
        d.one = 3; d.two = 2; d.three = 1; d.four = 1; d.five = 1; d.six = 1
        d.rerollBelow(cutoff: 4)
        let total = d.one + d.two + d.three + d.four + d.five + d.six
        #expect(total == 9)
    }

    @Test("rerollBelow: cutoff 1 is a no-op (empty range)")
    func rerollBelowCutoffOne() {
        var d = Dice()
        d.one = 3; d.six = 2
        d.rerollBelow(cutoff: 1)
        #expect(d.one == 3)
        #expect(d.six == 2)
    }

    @Test("rerollBelow: dice above cutoff are untouched")
    func rerollBelowPreservesHighFaces() {
        var d = Dice()
        d.one = 2; d.two = 2; d.three = 2; d.six = 4
        d.rerollBelow(cutoff: 4)
        // The 4 sixes were not in the reroll range and should be unchanged
        #expect(d.six == 4)
    }

    @Test("applyReroll: none mode leaves hasRerolled false")
    func applyRerollNoneMode() {
        let roll = Roll()
        roll.state = .hit
        roll.hitRerollMode = .none
        roll.applyReroll()
        #expect(roll.hitHasRerolled == false)
    }

    @Test("applyReroll: sets hasRerolled flag after use")
    func applyRerollSetsFlag() {
        let roll = Roll()
        roll.state = .hit
        roll.hitRerollMode = .ones
        roll.dice.one = 3; roll.dice.six = 2
        roll.total = 5
        roll.applyReroll()
        #expect(roll.hitHasRerolled == true)
    }

    @Test("applyReroll: guard blocks second call")
    func applyRerollRespectsFlagAlreadySet() {
        let roll = Roll()
        roll.state = .hit
        roll.hitRerollMode = .all
        roll.hitHasRerolled = true  // simulate already used
        roll.dice.one = 5           // known state
        roll.applyReroll()          // should be blocked by guard
        #expect(roll.dice.one   == 5)
        #expect(roll.dice.two   == 0)
        #expect(roll.dice.three == 0)
        #expect(roll.dice.four  == 0)
        #expect(roll.dice.five  == 0)
        #expect(roll.dice.six   == 0)
    }

    @Test("applyReroll: only sets flag for the active phase")
    func applyRerollPerPhaseIsolation() {
        let roll = Roll()
        roll.state = .wound
        roll.woundRerollMode = .ones
        roll.applyReroll()
        #expect(roll.woundHasRerolled == true)
        #expect(roll.hitHasRerolled   == false)
        #expect(roll.saveHasRerolled  == false)
    }

    @Test("applyReroll: failed mode preserves total dice count")
    func applyRerollFailedModeCount() {
        let roll = Roll()
        roll.state = .hit
        roll.hitCutoff = .four
        roll.hitRerollMode = .failed
        roll.dice.one = 1; roll.dice.two = 1; roll.dice.three = 1; roll.dice.six = 2
        roll.total = 5
        roll.applyReroll()
        let total = roll.dice.one + roll.dice.two + roll.dice.three +
                    roll.dice.four + roll.dice.five + roll.dice.six
        #expect(total == 5)
        #expect(roll.dice.six == 2) // dice above cutoff are untouched
    }

    @Test("resetPool: clears hitHasRerolled flag")
    func resetPoolClearsFlag() {
        let roll = Roll()
        roll.total = 5
        roll.hitHasRerolled = true
        roll.resetPool()
        #expect(roll.hitHasRerolled == false)
    }

    @Test("resetPool: rolls dice equal to total count")
    func resetPoolRollsCorrectCount() {
        let roll = Roll()
        roll.total = 10
        roll.resetPool()
        let total = roll.dice.one + roll.dice.two + roll.dice.three +
                    roll.dice.four + roll.dice.five + roll.dice.six
        #expect(total == 10)
    }
}

// MARK: - Blowup Logic

@Suite("Blowup Logic")
struct BlowupTests {

    @Test("blowup six: total increases by the original six count")
    func blowupSixIncreasesCount() {
        var d = Dice()
        d.one = 1; d.two = 1; d.six = 3
        let originalTotal = 5
        let originalSix   = 3
        d.blowup(dice: .six)
        let newTotal = d.one + d.two + d.three + d.four + d.five + d.six
        #expect(newTotal == originalTotal + originalSix)
    }

    @Test("blowup five: total increases by the original five and six count")
    func blowupFiveIncreasesCount() {
        var d = Dice()
        d.one = 1; d.five = 2; d.six = 3
        let originalTotal   = 6
        let originalFiveSix = 5
        d.blowup(dice: .five)
        let newTotal = d.one + d.two + d.three + d.four + d.five + d.six
        #expect(newTotal == originalTotal + originalFiveSix)
    }

    @Test("blowup six: no-op when no sixes in pool")
    func blowupSixNoop() {
        var d = Dice()
        d.one = 3; d.two = 2
        d.blowup(dice: .six)
        let total = d.one + d.two + d.three + d.four + d.five + d.six
        #expect(total == 5)
    }

    @Test("applyBlowup: sets blowupUsed flag")
    func applyBlowupSetsFlag() {
        let roll = Roll()
        roll.dice.six = 3
        roll.applyBlowup(face: .six)
        #expect(roll.blowupUsed == true)
    }

    @Test("applyBlowup: guard blocks second call")
    func applyBlowupGuard() {
        let roll = Roll()
        roll.dice.six = 2
        roll.blowupUsed = true  // already used
        let totalBefore = roll.dice.one + roll.dice.two + roll.dice.three +
                          roll.dice.four + roll.dice.five + roll.dice.six
        roll.applyBlowup(face: .six)
        let totalAfter = roll.dice.one + roll.dice.two + roll.dice.three +
                         roll.dice.four + roll.dice.five + roll.dice.six
        #expect(totalAfter == totalBefore)
    }

    @Test("applyBlowup: using any face disables both")
    func blowupAnyFaceDisablesBoth() {
        let roll = Roll()
        roll.dice.six = 2; roll.dice.five = 2
        roll.applyBlowup(face: .six)
        #expect(roll.blowupUsed == true)
        // Five blowup should now be blocked
        let totalBefore = roll.dice.one + roll.dice.two + roll.dice.three +
                          roll.dice.four + roll.dice.five + roll.dice.six
        roll.applyBlowup(face: .five)
        let totalAfter = roll.dice.one + roll.dice.two + roll.dice.three +
                         roll.dice.four + roll.dice.five + roll.dice.six
        #expect(totalAfter == totalBefore)
    }
}