Added support for generating SwiftUI Text concatenation variants

Sources/owowgenerate-ios/Writers/SwiftUICodeWriter.swift

@@ -10,7 +10,7 @@ func makeSwiftUICode(strings: StringsCollection) -> String {
     return writer.output
 }
 
-private func writeStrings(strings: StringsCollection, writer: inout SwiftCodeWriter) {
+fileprivate func writeStrings(strings: StringsCollection, writer: inout SwiftCodeWriter) {
     for (name, collection) in strings.subCollections.sorted(by: { $0.key < $1.key }) {
         writer.addLine()
 
@@ -25,8 +25,6 @@ private func writeStrings(strings: StringsCollection, writer: inout SwiftCodeWri
     }
 
     for key in strings.keys {
-        writer.addDocComment(key.comment)
-
         let memberName = (key.key.split(separator: ".").last ?? "").camelCase(delimiter: "-", upper: false)
 
         if key.placeholders.isEmpty {
@@ -37,6 +35,7 @@ private func writeStrings(strings: StringsCollection, writer: inout SwiftCodeWri
                 additionalArguments = ""
             }
 
+            writer.addDocComment(key.comment)
             writer.addLine("static var \(memberName): Text { Text(\"\(key.key)\"\(additionalArguments)) }")
         } else {
             let parameters = key.placeholders.enumerated().map { index, type in
@@ -45,11 +44,78 @@ private func writeStrings(strings: StringsCollection, writer: inout SwiftCodeWri
 
             let parameterUsage = key.placeholders.indices.map { "placeholder\($0)" }.joined(separator: ", ")
 
+            writer.addDocComment(key.comment)
             writer.inBlock("static func \(memberName)(\(parameters)) -> Text") { writer in
                 writer.addLine("let format = NSLocalizedString(\"\(key.key)\", comment: \(SwiftCodeWriter.makeStringLiteral(key.comment)))")
                 writer.addLine("let string = String(format: format, \(parameterUsage))")
                 writer.addLine("return Text(verbatim: string)")
             }
+
+            if key.placeholders.contains(.object) {
+                // Generate a variant that works with text concatenation
+                writeTextConcatenationFunction(writer: &writer, key: key, memberName: memberName)
+            }
         }
     }
 }
+
+fileprivate func writeTextConcatenationFunction(writer: inout SwiftCodeWriter, key: StringsEntry, memberName: String) {
+    func makePlaceholder(index: Int) -> String {
+        "⚠️OWOWGENERATE PLACEHOLDER \(index)⚠️"
+    }
+
+    let parameters = key.placeholders.enumerated().map { index, type in
+        let parameterType: String
+        if type == .object {
+            parameterType = "Text"
+        } else {
+            parameterType = type.rawValue
+        }
+
+        return "_ placeholder\(index): \(parameterType)"
+    }.joined(separator: ", ")
+
+    let parameterUsage = key.placeholders.enumerated().map { index, type in
+        if type == .object {
+            return SwiftCodeWriter.makeStringLiteral(makePlaceholder(index: index))
+        } else {
+            return "placeholder\(index)"
+        }
+    }.joined(separator: ", ")
+
+    guard let firstTextPlaceholderIndex = key.placeholders.firstIndex(of: .object), let lastTextPlaceholderIndex = key.placeholders.lastIndex(of: .object) else {
+        fatalError("No object placeholders while writing text concatenation function")
+    }
+
+    writer.addDocComment(key.comment)
+    writer.inBlock("static func \(memberName)(\(parameters)) -> Text") { writer in
+        writer.addLine("let format = NSLocalizedString(\"\(key.key)\", comment: \(SwiftCodeWriter.makeStringLiteral(key.comment)))")
+        writer.addLine("let temporaryString = String(format: format, \(parameterUsage))")
+
+        // first placeholder range
+        writer.inBlock("guard let placeholder\(firstTextPlaceholderIndex)Range = temporaryString.range(of: \(SwiftCodeWriter.makeStringLiteral(makePlaceholder(index: firstTextPlaceholderIndex)))) else") { writer in
+            writer.addLine("fatalError(\"Placeholder \(firstTextPlaceholderIndex) not found in string\")")
+        }
+
+        writer.addDocComment("Construct the first part of the text view, consisting of the static first portion until the first placeholder + the value for the first placeholder")
+        writer.addLine("var text = Text(verbatim: String(temporaryString[temporaryString.startIndex..<placeholder\(firstTextPlaceholderIndex)Range.lowerBound])) + placeholder\(firstTextPlaceholderIndex)")
+
+        let lastCodeGeneratedPlaceholderNumber = firstTextPlaceholderIndex
+
+        if firstTextPlaceholderIndex != lastTextPlaceholderIndex {
+            for (index, element) in key.placeholders.enumerated() where index > firstTextPlaceholderIndex && element == .object {
+                let placeholderString = makePlaceholder(index: index)
+                let placeholderStringLiteral = SwiftCodeWriter.makeStringLiteral(placeholderString)
+
+                writer.inBlock("guard let placeholder\(index)Range = temporaryString.range(of: \(placeholderStringLiteral)) else") { writer in
+                    writer.addLine("fatalError(\"Placeholder \(index) not found in string\")")
+                }
+
+                writer.addLine("text = text + Text(verbatim: String(temporaryString[placeholder\(lastCodeGeneratedPlaceholderNumber)Range.upperBound..<placeholder\(index)Range.lowerBound])) + placeholder\(index)")
+            }
+        }
+
+        writer.addLine("text = text + Text(verbatim: String(temporaryString[placeholder\(lastTextPlaceholderIndex)Range.upperBound..<temporaryString.endIndex]))")
+        writer.addLine("return text")
+    }
+}