import Foundation
import Testing

@testable import phbar

// MARK: - Per-monitor resolution
//
// `PHConfig` exposes one resolution API: `theme`/`window`/`blocks`/
// `monitorOverride`, each taking a pure `(screenName, screenIndex)` pair.
// Precedence for every field: override-by-name → override-by-index → global.

/// Build a `PHConfig` with sensible defaults so each test only spells out the
/// fields it cares about.
private func makeConfig(
	theme: String = "default",
	window: String = "default",
	blocks: String? = nil,
	monitors: [String: PHConfigMonitorOverride]? = nil
) -> PHConfig {
	PHConfig(theme: theme, window: window, blocks: blocks, env: nil, monitors: monitors)
}

// MARK: window

@Test func windowFallsBackToGlobal() {
	let config = makeConfig(window: "top")
	#expect(config.window(screenName: "Built-in", screenIndex: 0) == "top")
}

@Test func windowMatchesByIndex() {
	let config = makeConfig(monitors: ["1": .init(window: "bottom", layout: nil)])
	#expect(config.window(screenName: "Whatever", screenIndex: 1) == "bottom")
}

@Test func windowMatchesByName() {
	let config = makeConfig(monitors: ["DELL U2723QE": .init(window: "clock", layout: nil)])
	#expect(config.window(screenName: "DELL U2723QE", screenIndex: 0) == "clock")
}

@Test func windowPrefersNameOverIndex() {
	let config = makeConfig(monitors: [
		"0": .init(window: "byIndex", layout: nil),
		"DELL": .init(window: "byName", layout: nil),
	])
	#expect(config.window(screenName: "DELL", screenIndex: 0) == "byName")
}

// MARK: blocks

@Test func blocksDefaultsToDefault() {
	#expect(makeConfig().layout(screenName: "S", screenIndex: 0) == "default")
}

@Test func blocksUsesGlobalWhenNoOverride() {
	let config = makeConfig(blocks: "main")
	#expect(config.layout(screenName: "S", screenIndex: 0) == "main")
}

@Test func blocksOverrideBeatsGlobal() {
	let config = makeConfig(blocks: "main", monitors: ["1": .init(window: nil, layout: "alt")])
	#expect(config.layout(screenName: "S", screenIndex: 1) == "alt")
}

// MARK: theme

@Test func themeFallsBackToGlobal() {
	let config = makeConfig(theme: "voltage")
	#expect(config.theme(screenName: "S", screenIndex: 0) == "voltage")
}

@Test func themeOverrideBeatsGlobal() {
	let config = makeConfig(theme: "voltage", monitors: ["1": .init(theme: "mono", window: nil, blocks: nil)])
	#expect(config.theme(screenName: "S", screenIndex: 1) == "mono")
}

// MARK: independence

@Test func overrideInheritsUnsetFieldsFromGlobal() {
	// An override that sets only `blocks` still inherits the global window/theme.
	let config = makeConfig(theme: "voltage", window: "top", monitors: ["1": .init(window: nil, layout: "laptop")])
	#expect(config.theme(screenName: "S", screenIndex: 1) == "voltage")
	#expect(config.window(screenName: "S", screenIndex: 1) == "top")
	#expect(config.layout(screenName: "S", screenIndex: 1) == "laptop")
}

@Test func themeWindowAndBlocksResolveIndependently() {
	let config = makeConfig(
		theme: "voltage", window: "top", blocks: "main",
		monitors: [
			"DELL": .init(theme: "mono", window: "clock", blocks: nil), // inherits blocks "main"
			"1": .init(theme: nil, window: nil, blocks: "laptop"),       // inherits theme/window
		]
	)
	#expect(config.theme(screenName: "DELL", screenIndex: 0) == "mono")
	#expect(config.window(screenName: "DELL", screenIndex: 0) == "clock")
	#expect(config.blocks(screenName: "DELL", screenIndex: 0) == "main")

	#expect(config.theme(screenName: "S", screenIndex: 1) == "voltage")
	#expect(config.window(screenName: "S", screenIndex: 1) == "top")
	#expect(config.blocks(screenName: "S", screenIndex: 1) == "laptop")
}

// MARK: monitorOverride

@Test func monitorOverrideReturnsNilWhenTableAbsent() {
	#expect(makeConfig().monitorOverride(screenName: "S", screenIndex: 0) == nil)
}

@Test func monitorOverrideReturnsNilForUnmatchedScreen() {
	let config = makeConfig(monitors: ["DELL": .init(window: "clock", layout: nil)])
	#expect(config.monitorOverride(screenName: "Unknown", screenIndex: 99) == nil)
}