package transport

import (
	"strconv"
	"strings"

	"github.com/gin-gonic/gin"

	"github.com/geo-platform/tenant-api/internal/ops/app"
	"github.com/geo-platform/tenant-api/internal/shared/response"
)

type complianceDecisionRequest struct {
	Reason string `json:"reason" binding:"required"`
}

type complianceMasterSwitchRequest struct {
	Enabled bool `json:"enabled"`
}

type complianceRollbackRequest struct {
	Version int `json:"version" binding:"required"`
}

func listComplianceDictionariesHandler(svc *app.ComplianceService) gin.HandlerFunc {
	return func(c *gin.Context) {
		data, err := svc.ListDictionaries(c.Request.Context())
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, data)
	}
}

func createComplianceDictionaryHandler(svc *app.ComplianceService) gin.HandlerFunc {
	return func(c *gin.Context) {
		var body app.UpsertComplianceDictionaryRequest
		if err := c.ShouldBindJSON(&body); err != nil {
			response.Error(c, response.ErrBadRequest(40000, "invalid_payload", err.Error()))
			return
		}
		data, err := svc.CreateDictionary(c.Request.Context(), body)
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, data)
	}
}

func updateComplianceDictionaryHandler(svc *app.ComplianceService) gin.HandlerFunc {
	return func(c *gin.Context) {
		id, err := parseIDParam(c)
		if err != nil {
			response.Error(c, err)
			return
		}
		var body app.UpsertComplianceDictionaryRequest
		if err := c.ShouldBindJSON(&body); err != nil {
			response.Error(c, response.ErrBadRequest(40000, "invalid_payload", err.Error()))
			return
		}
		data, err := svc.UpdateDictionary(c.Request.Context(), id, body)
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, data)
	}
}

func deleteComplianceDictionaryHandler(svc *app.ComplianceService) gin.HandlerFunc {
	return func(c *gin.Context) {
		id, err := parseIDParam(c)
		if err != nil {
			response.Error(c, err)
			return
		}
		if err := svc.DeleteDictionary(c.Request.Context(), id); err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, gin.H{"deleted": true})
	}
}

func listComplianceTermsHandler(svc *app.ComplianceService) gin.HandlerFunc {
	return func(c *gin.Context) {
		id, err := parseIDParam(c)
		if err != nil {
			response.Error(c, err)
			return
		}
		data, err := svc.ListTerms(c.Request.Context(), id)
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, data)
	}
}

func createComplianceTermHandler(svc *app.ComplianceService) gin.HandlerFunc {
	return func(c *gin.Context) {
		id, err := parseIDParam(c)
		if err != nil {
			response.Error(c, err)
			return
		}
		var body app.CreateComplianceDictionaryTermRequest
		if err := c.ShouldBindJSON(&body); err != nil {
			response.Error(c, response.ErrBadRequest(40000, "invalid_payload", err.Error()))
			return
		}
		data, err := svc.CreateTerm(c.Request.Context(), id, body)
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, data)
	}
}

func deleteComplianceTermHandler(svc *app.ComplianceService) gin.HandlerFunc {
	return func(c *gin.Context) {
		dictID, err := parseIDParam(c)
		if err != nil {
			response.Error(c, err)
			return
		}
		termID, err := parsePositiveInt64(c.Param("term_id"))
		if err != nil {
			response.Error(c, response.ErrBadRequest(40001, "invalid_id", "无效的词条 ID"))
			return
		}
		if err := svc.DeleteTerm(c.Request.Context(), dictID, termID); err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, gin.H{"deleted": true})
	}
}

func batchImportComplianceTermsHandler(svc *app.ComplianceService) gin.HandlerFunc {
	return func(c *gin.Context) {
		id, err := parseIDParam(c)
		if err != nil {
			response.Error(c, err)
			return
		}
		var body app.BatchImportComplianceTermsRequest
		if err := c.ShouldBindJSON(&body); err != nil {
			response.Error(c, response.ErrBadRequest(40000, "invalid_payload", err.Error()))
			return
		}
		data, err := svc.BatchImportTerms(c.Request.Context(), id, body)
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, data)
	}
}

func publishComplianceDictionaryHandler(svc *app.ComplianceService) gin.HandlerFunc {
	return func(c *gin.Context) {
		id, err := parseIDParam(c)
		if err != nil {
			response.Error(c, err)
			return
		}
		data, err := svc.PublishDictionary(c.Request.Context(), id)
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, data)
	}
}

func rollbackComplianceDictionaryHandler(svc *app.ComplianceService) gin.HandlerFunc {
	return func(c *gin.Context) {
		id, err := parseIDParam(c)
		if err != nil {
			response.Error(c, err)
			return
		}
		var body complianceRollbackRequest
		if err := c.ShouldBindJSON(&body); err != nil {
			response.Error(c, response.ErrBadRequest(40000, "invalid_payload", err.Error()))
			return
		}
		data, err := svc.RollbackDictionary(c.Request.Context(), id, body.Version)
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, data)
	}
}

func getGlobalCompliancePolicyHandler(svc *app.ComplianceService) gin.HandlerFunc {
	return func(c *gin.Context) {
		data, err := svc.GetGlobalPolicy(c.Request.Context())
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, data)
	}
}

func updateGlobalCompliancePolicyHandler(svc *app.ComplianceService) gin.HandlerFunc {
	return func(c *gin.Context) {
		var body app.UpdateCompliancePolicyRequest
		if err := c.ShouldBindJSON(&body); err != nil {
			response.Error(c, response.ErrBadRequest(40000, "invalid_payload", err.Error()))
			return
		}
		data, err := svc.UpdateGlobalPolicy(c.Request.Context(), body)
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, data)
	}
}

func setGlobalComplianceMasterSwitchHandler(svc *app.ComplianceService) gin.HandlerFunc {
	return func(c *gin.Context) {
		var body complianceMasterSwitchRequest
		if err := c.ShouldBindJSON(&body); err != nil {
			response.Error(c, response.ErrBadRequest(40000, "invalid_payload", err.Error()))
			return
		}
		data, err := svc.SetGlobalMasterSwitch(c.Request.Context(), body.Enabled)
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, data)
	}
}

func listComplianceManualReviewsHandler(svc *app.ComplianceService) gin.HandlerFunc {
	return func(c *gin.Context) {
		page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
		pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", c.DefaultQuery("size", "50")))
		var tenantID *int64
		if raw := c.Query("tenant_id"); raw != "" {
			id, err := parsePositiveInt64(raw)
			if err != nil {
				response.Error(c, response.ErrBadRequest(40001, "invalid_id", "无效的租户 ID"))
				return
			}
			tenantID = &id
		}
		data, err := svc.ListManualReviews(c.Request.Context(), app.ComplianceManualReviewListRequest{
			Status:   c.Query("status"),
			TenantID: tenantID,
			Page:     page,
			PageSize: pageSize,
		})
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, data)
	}
}

func getComplianceManualReviewHandler(svc *app.ComplianceService) gin.HandlerFunc {
	return func(c *gin.Context) {
		id, err := parseIDParam(c)
		if err != nil {
			response.Error(c, err)
			return
		}
		data, err := svc.GetManualReview(c.Request.Context(), id)
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, data)
	}
}

func approveComplianceManualReviewHandler(svc *app.ComplianceService) gin.HandlerFunc {
	return requireComplianceReviewPermission(decideComplianceManualReviewHandler(svc, true))
}

func rejectComplianceManualReviewHandler(svc *app.ComplianceService) gin.HandlerFunc {
	return requireComplianceReviewPermission(decideComplianceManualReviewHandler(svc, false))
}

func decideComplianceManualReviewHandler(svc *app.ComplianceService, approve bool) gin.HandlerFunc {
	return func(c *gin.Context) {
		id, err := parseIDParam(c)
		if err != nil {
			response.Error(c, err)
			return
		}
		var body complianceDecisionRequest
		if err := c.ShouldBindJSON(&body); err != nil {
			response.Error(c, response.ErrBadRequest(40000, "invalid_payload", err.Error()))
			return
		}
		var data any
		if approve {
			data, err = svc.ApproveManualReview(c.Request.Context(), id, body.Reason)
		} else {
			data, err = svc.RejectManualReview(c.Request.Context(), id, body.Reason)
		}
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, data)
	}
}

func listComplianceRecordsHandler(svc *app.ComplianceService) gin.HandlerFunc {
	return func(c *gin.Context) {
		page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
		pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", c.DefaultQuery("size", "50")))
		var tenantID *int64
		if raw := c.Query("tenant_id"); raw != "" {
			id, err := parsePositiveInt64(raw)
			if err != nil {
				response.Error(c, response.ErrBadRequest(40001, "invalid_id", "无效的租户 ID"))
				return
			}
			tenantID = &id
		}
		var articleID *int64
		if raw := c.Query("article_id"); raw != "" {
			id, err := parsePositiveInt64(raw)
			if err != nil {
				response.Error(c, response.ErrBadRequest(40001, "invalid_id", "无效的文章 ID"))
				return
			}
			articleID = &id
		}
		data, err := svc.ListRecords(c.Request.Context(), app.ComplianceRecordListRequest{
			TenantID:  tenantID,
			ArticleID: articleID,
			Decision:  c.Query("decision"),
			Page:      page,
			PageSize:  pageSize,
		})
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, data)
	}
}

func complianceStatsHandler(svc *app.ComplianceService) gin.HandlerFunc {
	return func(c *gin.Context) {
		data, err := svc.Stats(c.Request.Context())
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, data)
	}
}

func requireComplianceReviewPermission(next gin.HandlerFunc) gin.HandlerFunc {
	return func(c *gin.Context) {
		actor := actorFromGin(c)
		if actor == nil || !strings.EqualFold(strings.TrimSpace(actor.Role), "admin") {
			response.Error(c, response.ErrForbidden(40331, "compliance_review_forbidden", "operator is not allowed to review compliance requests"))
			return
		}
		next(c)
	}
}

func parsePositiveInt64(raw string) (int64, error) {
	id, err := strconv.ParseInt(raw, 10, 64)
	if err != nil || id <= 0 {
		return 0, strconv.ErrSyntax
	}
	return id, nil
}