package api

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

	"github.com/go-chi/chi/v5"
	"github.com/will/k8s-agent-dashboard/internal/models"
	"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
		}

		// Queue workflow for execution
		respondJSON(w, http.StatusAccepted, map[string]interface{}{
			"status":   "queued",
			"workflow": name,
			"message":  "Workflow queued for execution. Use Claude Code CLI to run workflows.",
		})
	}
}

// AlertmanagerWebhook receives alerts from Alertmanager
func AlertmanagerWebhook(s *store.Store) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var payload struct {
			Alerts []struct {
				Status      string            `json:"status"`
				Labels      map[string]string `json:"labels"`
				Annotations map[string]string `json:"annotations"`
				StartsAt    string            `json:"startsAt"`
				EndsAt      string            `json:"endsAt"`
			} `json:"alerts"`
		}

		if err := json.NewDecoder(r.Body).Decode(&payload); err != nil {
			respondError(w, http.StatusBadRequest, "invalid payload")
			return
		}

		processed := 0
		for _, alert := range payload.Alerts {
			if alert.Status != "firing" {
				continue
			}

			alertName := alert.Labels["alertname"]
			namespace := alert.Labels["namespace"]
			pod := alert.Labels["pod"]

			// Map alerts to workflows and create pending actions
			var workflow string
			var description string

			switch alertName {
			case "KubePodCrashLooping", "KubePodNotReady":
				workflow = "pod-crashloop-remediation"
				description = "Pod " + pod + " in " + namespace + " is " + alertName
			case "KubeNodeNotReady", "KubeNodeUnreachable":
				workflow = "node-issue-response"
				description = "Node issue: " + alertName
			case "KubeMemoryOvercommit", "KubeCPUOvercommit":
				workflow = "resource-pressure-response"
				description = "Resource pressure: " + alertName
			default:
				continue
			}

			// Log the alert as a pending action for visibility
			s.AddPendingAction(models.PendingAction{
				ID:          "alert-" + alertName + "-" + namespace + "-" + pod,
				Agent:       "alertmanager",
				Action:      "run-workflow:" + workflow,
				Description: description,
				Risk:        "medium",
				Workflow:    workflow,
				Details: map[string]interface{}{
					"alertname": alertName,
					"namespace": namespace,
					"pod":       pod,
					"labels":    alert.Labels,
				},
			})
			processed++
		}

		respondJSON(w, http.StatusOK, map[string]interface{}{
			"status":    "received",
			"processed": processed,
			"total":     len(payload.Alerts),
		})
	}
}

// CompleteWorkflow marks a workflow as completed
func CompleteWorkflow(s *store.Store) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		name := chi.URLParam(r, "name")

		var body struct {
			LogFile  string `json:"log_file"`
			ExitCode int    `json:"exit_code"`
		}
		json.NewDecoder(r.Body).Decode(&body)

		respondJSON(w, http.StatusOK, map[string]interface{}{
			"status":   "completed",
			"workflow": name,
			"log_file": body.LogFile,
		})
	}
}