package handlers

import (
	"errors"
	"strconv"

	"github.com/gin-gonic/gin"

	"git.netcell-it.de/projekte/edgeguard-native/internal/handlers/response"
	"git.netcell-it.de/projekte/edgeguard-native/internal/services/alerts"
	"git.netcell-it.de/projekte/edgeguard-native/internal/services/audit"
)

// AlertsHandler exposes:
//
//	GET    /api/v1/alerts/channels
//	POST   /api/v1/alerts/channels
//	PUT    /api/v1/alerts/channels/:id
//	DELETE /api/v1/alerts/channels/:id
//	POST   /api/v1/alerts/test           — Test-Event in alle aktiven Channels
//	GET    /api/v1/alerts/events?limit=N — History
type AlertsHandler struct {
	Service *alerts.Service
	Audit   *audit.Repo
	NodeID  string
}

func NewAlertsHandler(s *alerts.Service, a *audit.Repo, nodeID string) *AlertsHandler {
	return &AlertsHandler{Service: s, Audit: a, NodeID: nodeID}
}

func (h *AlertsHandler) Register(rg *gin.RouterGroup) {
	g := rg.Group("/alerts")
	g.GET("/channels", h.ListChannels)
	g.POST("/channels", h.CreateChannel)
	g.PUT("/channels/:id", h.UpdateChannel)
	g.DELETE("/channels/:id", h.DeleteChannel)
	g.POST("/test", h.TestFire)
	g.GET("/events", h.ListEvents)
}

func (h *AlertsHandler) ListChannels(c *gin.Context) {
	out, err := h.Service.ListChannels(c.Request.Context())
	if err != nil {
		response.Internal(c, err)
		return
	}
	response.OK(c, gin.H{"channels": out})
}

func (h *AlertsHandler) CreateChannel(c *gin.Context) {
	var req alerts.Channel
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, err)
		return
	}
	out, err := h.Service.CreateChannel(c.Request.Context(), req)
	if err != nil {
		response.Internal(c, err)
		return
	}
	_ = h.Audit.Log(c.Request.Context(), actorOf(c), "alert.channel.create",
		out.Name, out, h.NodeID)
	response.Created(c, out)
}

func (h *AlertsHandler) UpdateChannel(c *gin.Context) {
	id, ok := parseID(c)
	if !ok {
		return
	}
	var req alerts.Channel
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, err)
		return
	}
	out, err := h.Service.UpdateChannel(c.Request.Context(), id, req)
	if err != nil {
		if errors.Is(err, alerts.ErrNotFound) {
			response.NotFound(c, err)
			return
		}
		response.Internal(c, err)
		return
	}
	_ = h.Audit.Log(c.Request.Context(), actorOf(c), "alert.channel.update",
		out.Name, out, h.NodeID)
	response.OK(c, out)
}

func (h *AlertsHandler) DeleteChannel(c *gin.Context) {
	id, ok := parseID(c)
	if !ok {
		return
	}
	if err := h.Service.DeleteChannel(c.Request.Context(), id); err != nil {
		if errors.Is(err, alerts.ErrNotFound) {
			response.NotFound(c, err)
			return
		}
		response.Internal(c, err)
		return
	}
	_ = h.Audit.Log(c.Request.Context(), actorOf(c), "alert.channel.delete",
		strconv.FormatInt(id, 10), gin.H{"id": id}, h.NodeID)
	response.NoContent(c)
}

func (h *AlertsHandler) TestFire(c *gin.Context) {
	ev, err := h.Service.Fire(c.Request.Context(), "test", alerts.SeverityInfo,
		"EdgeGuard-Test-Alert",
		"Dies ist ein Test-Event. Wenn du das siehst, funktionieren deine Alert-Channels.")
	if err != nil {
		response.Internal(c, err)
		return
	}
	_ = h.Audit.Log(c.Request.Context(), actorOf(c), "alert.test", "test", ev, h.NodeID)
	response.OK(c, ev)
}

func (h *AlertsHandler) ListEvents(c *gin.Context) {
	limit := 100
	if v := c.Query("limit"); v != "" {
		if n, err := strconv.Atoi(v); err == nil {
			limit = n
		}
	}
	out, err := h.Service.ListEvents(c.Request.Context(), limit)
	if err != nil {
		response.Internal(c, err)
		return
	}
	response.OK(c, gin.H{"events": out})
}