// Response parser for Anthropic Message API responses
// Ported from old_repo/services/api/errors.ts and claude.ts

import "api_types.dart";

// Parse Message API response into ApiMessage model
class ResponseParser {
  static ApiMessage parseMessageResponse(Map<String, dynamic> json) {
    return ApiMessage.fromJson(json);
  }

  static ApiMessage parseOpenRouterResponse(Map<String, dynamic> json) {
    return ApiMessage.fromOpenRouterResponse(json);
  }

  // extract text content from message
  static String extractTextContent(ApiMessage message) {
    final textBlocks = <String>[];

    for (final block in message.content) {
      if (block is Map<String, dynamic>) {
        final type = block["type"];
        if (type == "text") {
          final text = block["text"];
          if (text is String) {
            textBlocks.add(text);
          }
        }
      }
    }

    return textBlocks.join("\n");
  }

  // extract all tool use blocks from message
  static List<ToolUse> extractToolUseBlocks(ApiMessage message) {
    final tools = <ToolUse>[];

    for (final block in message.content) {
      if (block is Map<String, dynamic>) {
        final type = block["type"];
        if (type == "tool_use") {
          tools.add(ToolUse.fromJson(block));
        }
      }
    }

    return tools;
  }

  // check if message is a tool use (or contains only tool use)
  static bool hasToolUse(ApiMessage message) {
    return message.content.any((block) {
      return block is Map<String, dynamic> && block["type"] == "tool_use";
    });
  }

  // check stop reason
  static bool didStopOnToolUse(ApiMessage message) {
    return message.stopReason == "tool_use";
  }

  static bool didStopOnMaxTokens(ApiMessage message) {
    return message.stopReason == "max_tokens";
  }

  static bool didCompleteNormally(ApiMessage message) {
    return message.stopReason == "end_turn";
  }
}

// Parse error responses from the API
class ErrorParser {
  // check if raw API error is authentication related
  static bool isAuthenticationError(String errorMessage) {
    final lower = errorMessage.toLowerCase();
    return lower.contains("unauthorized") ||
        lower.contains("authentication") ||
        lower.contains("invalid api key") ||
        lower.contains("missing authentication");
  }

  // check if error is rate limit related
  static bool isRateLimitError(String errorMessage) {
    final lower = errorMessage.toLowerCase();
    return lower.contains("rate limit") ||
        lower.contains("too many requests") ||
        lower.contains("quota");
  }

  // check if error is related to prompt being too long
  static bool isPromptTooLongError(String errorMessage) {
    final lower = errorMessage.toLowerCase();
    return lower.contains("prompt is too long") ||
        lower.contains("context_length_exceeded");
  }

  // check if error is media/content related
  static bool isMediaSizeError(String errorMessage) {
    final lower = errorMessage.toLowerCase();
    return (lower.contains("image exceeds") && lower.contains("maximum")) ||
        (lower.contains("image dimensions exceed") &&
            lower.contains("many-image")) ||
        RegExp(
          r"maximum of \d+ pdf pages",
          caseSensitive: false,
        ).hasMatch(errorMessage);
  }

  // parse prompt too long error to extract token counts
  static ({int? actualTokens, int? limitTokens}) parsePromptTooLongError(
    String rawMessage,
  ) {
    final match = RegExp(
      r"prompt is too long[^0-9]*(\d+)\s*tokens?\s*>\s*(\d+)",
      caseSensitive: false,
    ).firstMatch(rawMessage);

    return (
      actualTokens: match != null ? int.tryParse(match.group(1)!) : null,
      limitTokens: match != null ? int.tryParse(match.group(2)!) : null,
    );
  }

  // extract server error message from API response
  static String? extractErrorMessage(Map<String, dynamic>? errorJson) {
    if (errorJson == null) return null;

    final nestedError = errorJson["error"];
    if (nestedError is Map<String, dynamic>) {
      final nestedMessage = nestedError["message"];
      if (nestedMessage is String && nestedMessage.isNotEmpty) {
        return nestedMessage;
      }
    }

    // try common error message fields
    return errorJson["message"] as String? ??
        errorJson["error"] as String? ??
        errorJson["detail"] as String?;
  }
}

// Streaming response parser for handling streamed API responses
class StreamingResponseParser {
  // parse a streamed event from newline-delimited JSON
  static Map<String, dynamic>? parseStreamLine(String line) {
    if (line.trim().isEmpty) return null;

    try {
      // handle SSE format (data: {...})
      final data = line.startsWith("data: ") ? line.substring(6) : line;
      // simple JSON parsing - in production would use json.decode
      return _parseJson(data);
    } catch (_) {
      return null;
    }
  }

  static Map<String, dynamic>? _parseJson(String jsonStr) {
    // stubbed - would use dart:convert.jsonDecode in real impl
    // for now just return null to indicate parsing would happen
    return null;
  }

  // check if streamed event is a message delta (partial response)
  static bool isMessageDelta(Map<String, dynamic>? event) {
    if (event == null) return false;
    final type = event["type"];
    return type == "content_block_delta";
  }

  // check if streamed event marks message completion
  static bool isMessageStop(Map<String, dynamic>? event) {
    if (event == null) return false;
    final type = event["type"];
    return type == "message_stop";
  }

  // extract partial text from delta event
  static String? extractDeltaText(Map<String, dynamic>? event) {
    if (event == null) return null;

    try {
      final delta = event["delta"] as Map<String, dynamic>?;
      if (delta == null) return null;

      final type = delta["type"];
      if (type == "text_delta") {
        return delta["text"] as String?;
      }
    } catch (_) {}

    return null;
  }
}