package httpmw

import (
	"context"
	"net/http"

	"github.com/go-chi/chi/v5"

	"github.com/coder/coder/v2/coderd/database"
	"github.com/coder/coder/v2/coderd/httpapi"
	"github.com/coder/coder/v2/codersdk"
)

type templateParamContextKey struct{}

// TemplateParam returns the template from the ExtractTemplateParam handler.
func TemplateParam(r *http.Request) database.Template {
	template, ok := r.Context().Value(templateParamContextKey{}).(database.Template)
	if !ok {
		panic("developer error: template param middleware not provided")
	}
	return template
}

// ExtractTemplateParam grabs a template from the "template" URL parameter.
func ExtractTemplateParam(db database.Store) func(http.Handler) http.Handler {
	return func(next http.Handler) http.Handler {
		return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
			ctx := r.Context()
			templateID, parsed := ParseUUIDParam(rw, r, "template")
			if !parsed {
				return
			}
			template, err := db.GetTemplateByID(r.Context(), templateID)
			if httpapi.Is404Error(err) || (err == nil && template.Deleted) {
				httpapi.ResourceNotFound(rw)
				return
			}
			if err != nil {
				httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
					Message: "Internal error fetching template.",
					Detail:  err.Error(),
				})
				return
			}

			ctx = context.WithValue(ctx, templateParamContextKey{}, template)
			chi.RouteContext(ctx).URLParams.Add("organization", template.OrganizationID.String())
			next.ServeHTTP(rw, r.WithContext(ctx))
		})
	}
}