import CoreGraphics
import Testing
@testable import Kanban

/// `BoardMetrics` — the board strip's arithmetic. Most of it is a multiple of the body font and
/// needs no assertion beyond the one every figure already carries (it renders what the board always
/// rendered at 13pt); what is worth pinning is the one figure that is *not* font-derived at all.

private let body: CGFloat = 13

@Suite("BoardMetrics · the card replica's width")
struct CardReplicaWidthTests {

    @Test("The measured face's width wins — the replica is the face it was lifted from")
    func measuredWidthWins() {
        // A face in a wide lane, and one in a narrow three-column lane: neither is the nominal
        // figure, and both are what the drag image must be drawn at.
        #expect(BoardMetrics.cardReplicaWidth(measured: 340, bodyPointSize: body) == 340)
        #expect(BoardMetrics.cardReplicaWidth(measured: 148, bodyPointSize: body) == 148)
    }

    @Test("A face that has not laid out yet falls back to the representative width")
    func unmeasuredFallsBack() {
        let fallback = BoardMetrics.cardReplicaWidth(bodyPointSize: body)
        #expect(BoardMetrics.cardReplicaWidth(measured: 0, bodyPointSize: body) == fallback)
        #expect(BoardMetrics.cardReplicaWidth(measured: -20, bodyPointSize: body) == fallback)
        #expect(BoardMetrics.cardReplicaWidth(measured: .nan, bodyPointSize: body) == fallback)
        #expect(BoardMetrics.cardReplicaWidth(measured: .infinity, bodyPointSize: body) == fallback)
    }

    @Test("The fallback scales with the body font, like every other figure here")
    func fallbackScales() {
        #expect(BoardMetrics.cardReplicaWidth(bodyPointSize: 26)
            > BoardMetrics.cardReplicaWidth(bodyPointSize: body))
    }
}