package api

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

	"git.pengzhan.dev/haopengzhan/rsspipe/internal/db"
	"git.pengzhan.dev/haopengzhan/rsspipe/internal/events"
	"git.pengzhan.dev/haopengzhan/rsspipe/internal/models"
	"git.pengzhan.dev/haopengzhan/rsspipe/internal/rules"
	"github.com/go-chi/chi/v5"
)

// Rules API Handlers
func (h *Handler) ListRules(w http.ResponseWriter, r *http.Request) {
	rulesList, err := h.db.ListRules()
	if err != nil {
		h.writeError(w, http.StatusInternalServerError, err.Error())
		return
	}
	if rulesList == nil {
		rulesList = []models.Rule{}
	}
	h.writeJSON(w, http.StatusOK, rulesList)
}

func (h *Handler) CreateRule(w http.ResponseWriter, r *http.Request) {
	var body models.Rule
	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
		h.writeError(w, http.StatusBadRequest, "invalid rule payload")
		return
	}

	body.Name = strings.TrimSpace(body.Name)
	if body.Name == "" {
		h.writeError(w, http.StatusBadRequest, "rule name is required")
		return
	}
	if body.Trigger == "" {
		body.Trigger = "on_update"
	}
	if body.MatchMode == "" {
		body.MatchMode = "all"
	}

	if err := rules.ValidateRuleSafety(body); err != nil {
		h.writeError(w, http.StatusBadRequest, err.Error())
		return
	}

	rule, err := h.db.CreateRule(body.Name, body.Trigger, body.MatchMode, body.Conditions, body.Actions)
	if err != nil {
		h.writeError(w, http.StatusInternalServerError, err.Error())
		return
	}
	h.writeJSON(w, http.StatusCreated, rule)
}

func (h *Handler) UpdateRule(w http.ResponseWriter, r *http.Request) {
	id := chi.URLParam(r, "id")
	var body models.Rule
	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
		h.writeError(w, http.StatusBadRequest, "invalid rule payload")
		return
	}

	body.Name = strings.TrimSpace(body.Name)
	if body.Name == "" {
		h.writeError(w, http.StatusBadRequest, "rule name is required")
		return
	}

	if err := rules.ValidateRuleSafety(body); err != nil {
		h.writeError(w, http.StatusBadRequest, err.Error())
		return
	}

	rule, err := h.db.UpdateRule(id, body.Name, body.Trigger, body.MatchMode, body.Conditions, body.Actions, body.IsActive)
	if err != nil {
		h.writeError(w, http.StatusInternalServerError, err.Error())
		return
	}
	h.writeJSON(w, http.StatusOK, rule)
}

func (h *Handler) DeleteRule(w http.ResponseWriter, r *http.Request) {
	id := chi.URLParam(r, "id")
	if err := h.db.DeleteRule(id); err != nil {
		h.writeError(w, http.StatusInternalServerError, err.Error())
		return
	}
	h.writeJSON(w, http.StatusOK, map[string]string{"message": "rule deleted"})
}

func (h *Handler) ApplyRule(w http.ResponseWriter, r *http.Request) {
	id := chi.URLParam(r, "id")
	rule, err := h.db.GetRule(id)
	if err != nil {
		h.writeError(w, http.StatusNotFound, "rule not found")
		return
	}

	entries, _, err := h.db.ListEntries(db.EntryFilter{Limit: 200})
	if err != nil {
		h.writeError(w, http.StatusInternalServerError, err.Error())
		return
	}

	eval := rules.NewEvaluator()
	matchedCount := 0

	for _, entry := range entries {
		if eval.Evaluate(*rule, entry) {
			matchedCount++
			if h.bus != nil {
				h.bus.Publish(r.Context(), events.Event{
					Type:  events.EventManualTrigger,
					Entry: entry,
					Depth: 0,
				})
			}
		}
	}

	h.writeJSON(w, http.StatusOK, map[string]interface{}{
		"message":       "rule applied to matching articles",
		"matched_count": matchedCount,
		"queued_jobs":   matchedCount * len(rule.Actions),
	})
}