package com.dalab.policyengine.web.rest;

import java.net.URI;
import java.util.UUID;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.web.PageableDefault;
import org.springframework.http.ResponseEntity;
import org.springframework.security.access.prepost.PreAuthorize;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.support.ServletUriComponentsBuilder;

import com.dalab.common.security.SecurityUtils;
import com.dalab.policyengine.dto.PolicyEvaluationOutputDTO;
import com.dalab.policyengine.dto.PolicyEvaluationRequestDTO;
import com.dalab.policyengine.dto.PolicyEvaluationSummaryDTO;
import com.dalab.policyengine.service.IPolicyEvaluationService;

import jakarta.validation.Valid;

@RestController
@RequestMapping("/api/v1/policyengine")
public class PolicyEvaluationController {

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

    private final IPolicyEvaluationService policyEvaluationService;

    @Autowired
    public PolicyEvaluationController(IPolicyEvaluationService policyEvaluationService) {
        this.policyEvaluationService = policyEvaluationService;
    }

    @PostMapping("/{policyId}/evaluations")
    @PreAuthorize("hasAnyAuthority('ROLE_ADMIN', 'ROLE_SYSTEM')")
    public ResponseEntity<PolicyEvaluationOutputDTO> triggerPolicyEvaluation(
            @PathVariable UUID policyId,
            @Valid @RequestBody PolicyEvaluationRequestDTO evaluationRequest) {
        log.info("REST request to trigger evaluation for Policy: {}", policyId);
        
        UUID triggeredByUserId = SecurityUtils.getAuthenticatedUserId(); // Can be null if system-triggered via Kafka
        PolicyEvaluationOutputDTO evaluation = policyEvaluationService.triggerPolicyEvaluation(policyId, evaluationRequest, triggeredByUserId);
        
        URI location = ServletUriComponentsBuilder.fromCurrentRequest()
                .path("/{evaluationId}")
                .buildAndExpand(evaluation.getId())
                .toUri();
        
        return ResponseEntity.created(location).body(evaluation);
    }

    @GetMapping("/evaluations")
    @PreAuthorize("hasAnyAuthority('ROLE_ADMIN', 'ROLE_POLICY_MANAGER', 'ROLE_AUDITOR')")
    public ResponseEntity<Page<PolicyEvaluationSummaryDTO>> getPolicyEvaluations(
            @PageableDefault(size = 50, sort = "evaluatedAt") Pageable pageable,
            @RequestParam(required = false) UUID policyId,
            @RequestParam(required = false) String targetAssetId,
            @RequestParam(required = false) String status) {
        log.info("REST request to get Policy Evaluations with filters: policyId={}, targetAssetId={}, status={}", policyId, targetAssetId, status);
        Page<PolicyEvaluationSummaryDTO> resultPage = policyEvaluationService.getPolicyEvaluations(pageable, policyId, targetAssetId, status);
        return ResponseEntity.ok(resultPage);
    }

    @GetMapping("/evaluations/{evaluationId}")
    @PreAuthorize("hasAnyAuthority('ROLE_ADMIN', 'ROLE_POLICY_MANAGER', 'ROLE_AUDITOR')")
    public ResponseEntity<PolicyEvaluationOutputDTO> getPolicyEvaluationById(@PathVariable UUID evaluationId) {
        log.info("REST request to get Policy Evaluation by id: {}", evaluationId);
        PolicyEvaluationOutputDTO evaluationDTO = policyEvaluationService.getPolicyEvaluationById(evaluationId);
        return ResponseEntity.ok(evaluationDTO);
    }
}