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/models"
	"git.netcell-it.de/projekte/edgeguard-native/internal/services/audit"
	"git.netcell-it.de/projekte/edgeguard-native/internal/services/backends"
)

type BackendsHandler struct {
	Repo     *backends.Repo
	Audit    *audit.Repo
	NodeID   string
	Reloader func(ctx context.Context) error
}

func NewBackendsHandler(repo *backends.Repo, a *audit.Repo, nodeID string, reloader func(context.Context) error) *BackendsHandler {
	return &BackendsHandler{Repo: repo, Audit: a, NodeID: nodeID, Reloader: reloader}
}

func (h *BackendsHandler) reload(ctx context.Context, op string) {
	if h.Reloader == nil {
		return
	}
	if err := h.Reloader(ctx); err != nil {
		slog.Warn("haproxy: reload after backend mutation failed", "op", op, "error", err)
	}
}

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

func (h *BackendsHandler) 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{"backends": out})
}

func (h *BackendsHandler) Get(c *gin.Context) {
	id, ok := parseID(c)
	if !ok {
		return
	}
	b, err := h.Repo.Get(c.Request.Context(), id)
	if err != nil {
		if errors.Is(err, backends.ErrNotFound) {
			response.NotFound(c, err)
			return
		}
		response.Internal(c, err)
		return
	}
	response.OK(c, b)
}

func (h *BackendsHandler) Create(c *gin.Context) {
	var req models.Backend
	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), "backend.create", req.Name, out, h.NodeID)
	response.Created(c, out); h.reload(c.Request.Context(), "create")
}

func (h *BackendsHandler) Update(c *gin.Context) {
	id, ok := parseID(c)
	if !ok {
		return
	}
	var req models.Backend
	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, backends.ErrNotFound) {
			response.NotFound(c, err)
			return
		}
		response.Internal(c, err)
		return
	}
	_ = h.Audit.Log(c.Request.Context(), actorOf(c), "backend.update", out.Name, out, h.NodeID)
	response.OK(c, out); h.reload(c.Request.Context(), "update")
}

func (h *BackendsHandler) 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, backends.ErrNotFound) {
			response.NotFound(c, err)
			return
		}
		response.Internal(c, err)
		return
	}
	_ = h.Audit.Log(c.Request.Context(), actorOf(c), "backend.delete",
		strconv.FormatInt(id, 10), gin.H{"id": id}, h.NodeID)
	response.NoContent(c); h.reload(c.Request.Context(), "delete")
}