package api

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

	"github.com/go-chi/chi/v5"
	"github.com/will/k8s-agent-dashboard/internal/store"
)

// JSON helper
func respondJSON(w http.ResponseWriter, status int, data interface{}) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	json.NewEncoder(w).Encode(data)
}

func respondError(w http.ResponseWriter, status int, message string) {
	respondJSON(w, status, map[string]string{"error": message})
}

// HealthCheck returns API health status
func HealthCheck(w http.ResponseWriter, r *http.Request) {
	respondJSON(w, http.StatusOK, map[string]string{
		"status": "ok",
		"service": "k8s-agent-dashboard",
	})
}

// GetClusterStatus returns current cluster status
func GetClusterStatus(s *store.Store) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		status := s.GetClusterStatus()
		respondJSON(w, http.StatusOK, status)
	}
}

// GetPendingActions returns all pending actions
func GetPendingActions(s *store.Store) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		actions := s.GetPendingActions()
		respondJSON(w, http.StatusOK, map[string]interface{}{
			"count":   len(actions),
			"actions": actions,
		})
	}
}

// ApproveAction approves a pending action
func ApproveAction(s *store.Store) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		id := chi.URLParam(r, "id")
		if id == "" {
			respondError(w, http.StatusBadRequest, "missing action id")
			return
		}

		var body struct {
			Reason string `json:"reason"`
		}
		json.NewDecoder(r.Body).Decode(&body)

		action, err := s.ApproveAction(id, body.Reason)
		if err != nil {
			respondError(w, http.StatusNotFound, err.Error())
			return
		}

		respondJSON(w, http.StatusOK, map[string]interface{}{
			"status":  "approved",
			"action":  action,
			"message": "Action approved and ready for execution",
		})
	}
}

// RejectAction rejects a pending action
func RejectAction(s *store.Store) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		id := chi.URLParam(r, "id")
		if id == "" {
			respondError(w, http.StatusBadRequest, "missing action id")
			return
		}

		var body struct {
			Reason string `json:"reason"`
		}
		json.NewDecoder(r.Body).Decode(&body)

		if body.Reason == "" {
			body.Reason = "Rejected by user"
		}

		action, err := s.RejectAction(id, body.Reason)
		if err != nil {
			respondError(w, http.StatusNotFound, err.Error())
			return
		}

		respondJSON(w, http.StatusOK, map[string]interface{}{
			"status":  "rejected",
			"action":  action,
			"message": "Action rejected",
		})
	}
}

// GetActionHistory returns action history
func GetActionHistory(s *store.Store) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		limitStr := r.URL.Query().Get("limit")
		limit := 50
		if limitStr != "" {
			if l, err := strconv.Atoi(limitStr); err == nil {
				limit = l
			}
		}

		history := s.GetActionHistory(limit)
		respondJSON(w, http.StatusOK, map[string]interface{}{
			"count":   len(history),
			"history": history,
		})
	}
}

// GetWorkflows returns defined workflows
func GetWorkflows(s *store.Store) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		workflows := s.GetWorkflows()
		respondJSON(w, http.StatusOK, map[string]interface{}{
			"count":     len(workflows),
			"workflows": workflows,
		})
	}
}

// RunWorkflow triggers a workflow execution
func RunWorkflow(s *store.Store) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		name := chi.URLParam(r, "name")
		if name == "" {
			respondError(w, http.StatusBadRequest, "missing workflow name")
			return
		}

		// In Phase 2, we just acknowledge the request
		// Phase 3 will implement actual execution via Claude Code
		respondJSON(w, http.StatusAccepted, map[string]interface{}{
			"status":   "queued",
			"workflow": name,
			"message":  "Workflow queued for execution. Use Claude Code CLI to run workflows.",
		})
	}
}