import Foundation
import Testing
import TOML

@testable import phbar

// MARK: - expand

@Test func envExpandDollarBraceForm() {
	let env = PHEnvironment(variables: ["ACCENT": "#ff0000"])
	#expect(env.expand("${ACCENT}") == "#ff0000")
}

@Test func envExpandDollarForm() {
	let env = PHEnvironment(variables: ["FOO": "bar"])
	#expect(env.expand("$FOO") == "bar")
}

@Test func envExpandsEmbeddedReferences() {
	let env = PHEnvironment(variables: ["HOME": "/Users/tom", "BIN": "/opt/bin"])
	#expect(env.expand("$HOME/bin:${BIN}/extra") == "/Users/tom/bin:/opt/bin/extra")
}

@Test func envExpandLeavesUnresolvedIntact() {
	// Unresolved references stay literal instead of being blanked, so a typo
	// remains visible.
	let env = PHEnvironment(variables: [:])
	#expect(env.expand("$MISSING and ${ALSO_MISSING}") == "$MISSING and ${ALSO_MISSING}")
}

@Test func envExpandIgnoresNonIdentifierDollar() {
	let env = PHEnvironment(variables: ["FOO": "bar"])
	// A `$` not followed by an identifier name is left untouched.
	#expect(env.expand("cost: $5 and $FOO") == "cost: $5 and bar")
}

// MARK: - merging

@Test func envMergingOverridesExistingKeys() {
	let env = PHEnvironment(variables: ["PATH": "/usr/bin", "HOME": "/u"])
	let merged = env.merging(["PATH": "/usr/bin:/extra"])
	#expect(merged.variables["PATH"] == "/usr/bin:/extra")
	#expect(merged.variables["HOME"] == "/u")
}

@Test func envMergingNilReturnsSameVariables() {
	let env = PHEnvironment(variables: ["A": "1"])
	#expect(env.merging(nil).variables == ["A": "1"])
}

// MARK: - [env] value expansion (config load)

private func makeConfig(env: [String: String]?) -> PHConfig {
	PHConfig(theme: "default", window: "default", blocks: nil, env: env, monitors: nil)
}

@Test func resolvingEnvExpandsValuesAgainstGivenEnvironment() {
	// `PATH = "$PATH:/extra"` extends an inherited variable.
	let config = makeConfig(env: [
		"PATH": "$PATH:/opt/phbar/bin",
		"WORKDIR": "${TMPDIR}/phbar",
		"PLAIN": "literal",
	])
	let resolved = config.resolvingEnv(in: PHEnvironment(variables: [
		"PATH": "/usr/bin",
		"TMPDIR": "/var/tmp",
	]))

	#expect(resolved.env?["PATH"] == "/usr/bin:/opt/phbar/bin")
	#expect(resolved.env?["WORKDIR"] == "/var/tmp/phbar")
	#expect(resolved.env?["PLAIN"] == "literal")
}

@Test func resolvingEnvDefaultsToProcessEnvironment() {
	// `$TMPDIR` is set in phbar's launch environment, so this also exercises
	// real process-env expansion end to end.
	guard let tmpdir = ProcessInfo.processInfo.environment["TMPDIR"] else { return }
	let config = makeConfig(env: ["OUT": "$TMPDIR"])
	let resolved = config.resolvingEnv()
	#expect(resolved.env?["OUT"] == tmpdir)
}

@Test func resolvingEnvLeavesConfigUntouchedWhenEnvAbsent() {
	let config = makeConfig(env: nil)
	#expect(config.resolvingEnv(in: .process).env == nil)
}

// MARK: - @EnvExpanded wrapper

/// Stand-in Decodable that mirrors how a theme field opts into expansion.
private struct Color: Decodable {
	@EnvExpanded var hex: String
}

@Test func envExpandedResolvesAgainstInjectedEnvironment() throws {
	let decoder = TOMLDecoder()
	decoder.userInfo[PHEnvironment.userInfoKey] = PHEnvironment(variables: ["ACCENT": "#ff0000"])

	let color = try decoder.decode(Color.self, from: #"hex = "$ACCENT""#)

	#expect(color.hex == "#ff0000")
}

@Test func envExpandedFallsBackToLaunchEnvironment() throws {
	// Without injected userInfo the wrapper falls back to phbar's launch
	// environment (`ProcessInfo`), which is a snapshot taken at process start.
	guard let path = ProcessInfo.processInfo.environment["PATH"] else { return }

	let color = try TOMLDecoder().decode(Color.self, from: #"hex = "$PATH""#)

	#expect(color.hex == path)
}

@Test func envExpandedLeavesUnresolvedIntact() throws {
	let color = try TOMLDecoder().decode(Color.self, from: #"hex = "$NEVER_SET""#)

	#expect(color.hex == "$NEVER_SET")
}

// MARK: - Theme integration

@Test func themeStyleColorExpandsEnvReference() throws {
	let decoder = TOMLDecoder()
	decoder.userInfo[PHEnvironment.userInfoKey] = PHEnvironment(variables: ["ACCENT": "#ff0000"])

	let style = try decoder.decode(PHThemeStyleColor.self, from: #"color = "$ACCENT""#)

	#expect(style.color == "#ff0000")
}

@Test func themeTextFontExpandsEnvReference() throws {
	let decoder = TOMLDecoder()
	decoder.userInfo[PHEnvironment.userInfoKey] = PHEnvironment(variables: ["FONT": "Comic Code"])

	let text = try decoder.decode(
		PHThemeText.self,
		from: """
		name   = "default"
		font   = "$FONT"
		size   = 14
		weight = "regular"
		style  = "normal"
		"""
	)

	#expect(text.fontFamily == "Comic Code")
}