refactor(click-to-pay): extract parsers, scripts, and webview management

[manideepk90]

Type of Change

• Bugfix
• Feature
• Refactor
• Chore
• CI/CD
• Docs

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Summary

Extract three major concerns from DefaultClickToPaySessionLauncher into separate files for better
maintainability and testability:

1. JSON Parsing (ClickToPayResponseDecoder.kt)

• Centralized all JSONObject/JSONArray parsing logic
• Added type-safe DecodeResult<T> sealed class for proper error handling
• Decodes: CustomerPresence, CardsStatus, RecognizedCards, CheckoutResponse, SignOutResponse

2. JavaScript Code (ClickToPayScripts.kt)

• Moved all inline JS strings to dedicated Kotlin functions
• Functions for: SDK initialization, session management, card operations, checkout
• Keeps main launcher code clean and JavaScript logic easier to maintain

3. WebView Lifecycle (ClickToPayWebViewManager.kt)

• Extracted WebView initialization, attach/detach, and destroy logic
• Centralized pending request management with ConcurrentHashMap
• Proper Mutex-based synchronization for lifecycle operations
• Correlation ID tracking for network requests

Benefits

• Reduced DefaultClickToPaySessionLauncher from 1,272 to 837 lines (34% reduction)
• Better separation of concerns - each class has a single responsibility
• Easier to test individual components in isolation
• Type-safe error handling with DecodeResult<T>
• No changes to public API - fully backward compatible

Bug Fixes Applied During Refactor

1. Fixed requestId mismatch in evaluateJavascriptOnMainThread - was ignoring passed requestId and
   creating new one, causing hangs
2. Fixed mixedContentMode value - corrected typo "compactability" → "always"

Verification

• Logger EventNames and values match original exactly
• All 9 JS evaluation call sites pass requestId correctly
• Build compiles successfully
• No memory leaks introduced (same cleanup as original)

Files Changed

File	Change
ClickToPayResponseDecoder.kt	New - JSON parsing with DecodeResult
ClickToPayScripts.kt	New - All JavaScript code extraction
ClickToPayWebViewManager.kt	New - WebView lifecycle management
DefaultClickToPaySessionLauncher.kt	Modified - Delegates to new classes

Affected Area & Impact

• Android Click-To-Pay SDK
• iOS
• Shared Core

Testing

• Compiled successfully (./gradlew :hyperswitch-sdk-android-click-to-pay:compileDebugKotlin)
• Manually tested in Android demo app
• Verified logger output matches original

Checklist

• Code follows project style guidelines
• No new warnings introduced
• Logging parity verified with main branch