package com.aiteacher.config;

import com.aiteacher.book.NoKnowledgeSourceException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;
import org.springframework.web.multipart.MaxUploadSizeExceededException;

import java.util.Map;
import java.util.NoSuchElementException;

@RestControllerAdvice
public class GlobalExceptionHandler {

    private static final Logger log = LoggerFactory.getLogger(GlobalExceptionHandler.class);

    @ExceptionHandler(NoKnowledgeSourceException.class)
    public ResponseEntity<Map<String, String>> handleNoKnowledgeSource(NoKnowledgeSourceException ex) {
        return ResponseEntity.status(HttpStatus.SERVICE_UNAVAILABLE)
            .body(Map.of("error", ex.getMessage()));
    }

    @ExceptionHandler(NoSuchElementException.class)
    public ResponseEntity<Map<String, String>> handleNotFound(NoSuchElementException ex) {
        return ResponseEntity.status(HttpStatus.NOT_FOUND)
            .body(Map.of("error", ex.getMessage()));
    }

    @ExceptionHandler(IllegalArgumentException.class)
    public ResponseEntity<Map<String, String>> handleBadRequest(IllegalArgumentException ex) {
        return ResponseEntity.status(HttpStatus.BAD_REQUEST)
            .body(Map.of("error", ex.getMessage()));
    }

    @ExceptionHandler(IllegalStateException.class)
    public ResponseEntity<Map<String, String>> handleConflict(IllegalStateException ex) {
        return ResponseEntity.status(HttpStatus.CONFLICT)
            .body(Map.of("error", ex.getMessage()));
    }

    @ExceptionHandler(MaxUploadSizeExceededException.class)
    public ResponseEntity<Map<String, String>> handleMaxUploadSize(MaxUploadSizeExceededException ex) {
        return ResponseEntity.status(HttpStatus.PAYLOAD_TOO_LARGE)
            .body(Map.of("error", "File exceeds maximum size of 100 MB."));
    }

    @ExceptionHandler(Exception.class)
    public ResponseEntity<Map<String, String>> handleGeneric(Exception ex) {
        log.error("Unhandled exception", ex);
        return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
            .body(Map.of("error", "An unexpected error occurred."));
    }
}