package handlers

import (
	"context"
	"errors"
	"log/slog"
	"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/audit"
	"git.netcell-it.de/projekte/edgeguard-native/internal/services/staticroutes"
)

// RoutesHandler exposes:
//
//	GET    /api/v1/routes           — verwaltete Routen aus DB
//	POST   /api/v1/routes           — anlegen
//	PUT    /api/v1/routes/:id       — ändern
//	DELETE /api/v1/routes/:id       — löschen
//	GET    /api/v1/routes/live      — Live-Routen vom Kernel (ip -j route)
type RoutesHandler struct {
	Repo     *staticroutes.Repo
	Renderer *staticroutes.Generator
	Audit    *audit.Repo
	NodeID   string
}

func NewRoutesHandler(repo *staticroutes.Repo, gen *staticroutes.Generator,
	a *audit.Repo, nodeID string) *RoutesHandler {
	return &RoutesHandler{Repo: repo, Renderer: gen, Audit: a, NodeID: nodeID}
}

func (h *RoutesHandler) Register(rg *gin.RouterGroup) {
	g := rg.Group("/routes")
	g.GET("", h.List)
	g.POST("", h.Create)
	g.PUT("/:id", h.Update)
	g.DELETE("/:id", h.Delete)
	g.GET("/live", h.Live)
}

func (h *RoutesHandler) reload(ctx context.Context, op string) {
	if h.Renderer == nil {
		return
	}
	if err := h.Renderer.Render(ctx); err != nil {
		slog.Warn("routes: render+apply failed", "op", op, "error", err)
	}
}

func (h *RoutesHandler) List(c *gin.Context) {
	out, err := h.Repo.List(c.Request.Context())
	if err != nil {
		response.Internal(c, err)
		return
	}
	response.OK(c, gin.H{"routes": out})
}

func (h *RoutesHandler) Create(c *gin.Context) {
	var req staticroutes.Route
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, err)
		return
	}
	out, err := h.Repo.Create(c.Request.Context(), req)
	if err != nil {
		response.Internal(c, err)
		return
	}
	_ = h.Audit.Log(c.Request.Context(), actorOf(c), "route.create", out.Destination, out, h.NodeID)
	response.Created(c, out)
	h.reload(c.Request.Context(), "create")
}

func (h *RoutesHandler) Update(c *gin.Context) {
	id, ok := parseID(c)
	if !ok {
		return
	}
	var req staticroutes.Route
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, err)
		return
	}
	out, err := h.Repo.Update(c.Request.Context(), id, req)
	if err != nil {
		if errors.Is(err, staticroutes.ErrNotFound) {
			response.NotFound(c, err)
			return
		}
		response.Internal(c, err)
		return
	}
	_ = h.Audit.Log(c.Request.Context(), actorOf(c), "route.update", out.Destination, out, h.NodeID)
	response.OK(c, out)
	h.reload(c.Request.Context(), "update")
}

func (h *RoutesHandler) Delete(c *gin.Context) {
	id, ok := parseID(c)
	if !ok {
		return
	}
	if err := h.Repo.Delete(c.Request.Context(), id); err != nil {
		if errors.Is(err, staticroutes.ErrNotFound) {
			response.NotFound(c, err)
			return
		}
		response.Internal(c, err)
		return
	}
	_ = h.Audit.Log(c.Request.Context(), actorOf(c), "route.delete",
		strconv.FormatInt(id, 10), gin.H{"id": id}, h.NodeID)
	response.NoContent(c)
	h.reload(c.Request.Context(), "delete")
}

func (h *RoutesHandler) Live(c *gin.Context) {
	routes, err := staticroutes.LiveAll(c.Request.Context())
	if err != nil {
		response.Internal(c, err)
		return
	}
	response.OK(c, gin.H{"routes": routes})
}