package httpapi

import (
	"encoding/json"
	"errors"
	"net/http"
	"strings"

	"github.com/easyai/easyai-ai-gateway/apps/api/internal/store"
)

func (s *Server) listPricingRuleSets(w http.ResponseWriter, r *http.Request) {
	items, err := s.store.ListPricingRuleSets(r.Context())
	if err != nil {
		s.logger.Error("list pricing rule sets failed", "error", err)
		writeError(w, http.StatusInternalServerError, "list pricing rule sets failed")
		return
	}
	writeJSON(w, http.StatusOK, map[string]any{"items": items})
}

func (s *Server) createPricingRuleSet(w http.ResponseWriter, r *http.Request) {
	var input store.PricingRuleSetInput
	if err := json.NewDecoder(r.Body).Decode(&input); err != nil {
		writeError(w, http.StatusBadRequest, "invalid json body")
		return
	}
	if !validPricingRuleSetInput(input) {
		writeError(w, http.StatusBadRequest, "ruleSetKey, name and at least one rule are required")
		return
	}
	item, err := s.store.CreatePricingRuleSet(r.Context(), input)
	if err != nil {
		if store.IsUniqueViolation(err) {
			writeError(w, http.StatusConflict, "pricing rule set key already exists")
			return
		}
		s.logger.Error("create pricing rule set failed", "error", err)
		writeError(w, http.StatusInternalServerError, "create pricing rule set failed")
		return
	}
	writeJSON(w, http.StatusCreated, item)
}

func (s *Server) updatePricingRuleSet(w http.ResponseWriter, r *http.Request) {
	var input store.PricingRuleSetInput
	if err := json.NewDecoder(r.Body).Decode(&input); err != nil {
		writeError(w, http.StatusBadRequest, "invalid json body")
		return
	}
	if !validPricingRuleSetInput(input) {
		writeError(w, http.StatusBadRequest, "ruleSetKey, name and at least one rule are required")
		return
	}
	item, err := s.store.UpdatePricingRuleSet(r.Context(), r.PathValue("ruleSetID"), input)
	if err != nil {
		if store.IsNotFound(err) {
			writeError(w, http.StatusNotFound, "pricing rule set not found")
			return
		}
		if store.IsUniqueViolation(err) {
			writeError(w, http.StatusConflict, "pricing rule set key already exists")
			return
		}
		s.logger.Error("update pricing rule set failed", "error", err)
		writeError(w, http.StatusInternalServerError, "update pricing rule set failed")
		return
	}
	writeJSON(w, http.StatusOK, item)
}

func (s *Server) deletePricingRuleSet(w http.ResponseWriter, r *http.Request) {
	if err := s.store.DeletePricingRuleSet(r.Context(), r.PathValue("ruleSetID")); err != nil {
		if store.IsNotFound(err) {
			writeError(w, http.StatusNotFound, "pricing rule set not found")
			return
		}
		if errors.Is(err, store.ErrProtectedDefault) {
			writeError(w, http.StatusForbidden, "default pricing rule set cannot be deleted")
			return
		}
		s.logger.Error("delete pricing rule set failed", "error", err)
		writeError(w, http.StatusInternalServerError, "delete pricing rule set failed")
		return
	}
	w.WriteHeader(http.StatusNoContent)
}

func validPricingRuleSetInput(input store.PricingRuleSetInput) bool {
	if strings.TrimSpace(input.RuleSetKey) == "" || strings.TrimSpace(input.Name) == "" || len(input.Rules) == 0 {
		return false
	}
	for _, rule := range input.Rules {
		if strings.TrimSpace(rule.ResourceType) == "" || strings.TrimSpace(rule.Unit) == "" {
			return false
		}
	}
	return true
}