package handlers

import (
	"fmt"
	"strings"

	"github.com/gofiber/fiber/v2"

	"polar/internal/web/middleware"
)

// RepoForkSubmit creates a fork of the repository for the current user.
func (h *Handler) RepoForkSubmit(c *fiber.Ctx) error {
	r, _, err := h.loadAuthorizedRepo(c, false)
	if err != nil {
		return nil
	}

	u := middleware.CurrentUser(c)
	if u == nil {
		return c.Redirect("/login", fiber.StatusSeeOther)
	}

	if u.ID == r.OwnerID {
		h.setFlashT(c, "flash.fork_self")
		return c.Redirect(fmt.Sprintf("/%s/%s", r.OwnerUsername, r.Name), fiber.StatusSeeOther)
	}

	if existing, _ := h.repoSvc.FindForkByOwner(c.UserContext(), r.ID, u.ID); existing != nil {
		h.setFlashT(c, "flash.fork_exists")
		return c.Redirect(fmt.Sprintf("/%s/%s", existing.OwnerUsername, existing.Name), fiber.StatusSeeOther)
	}

	name := strings.TrimSpace(c.FormValue("name"))
	newFork := r
	if r.ForkedFromRepoID != nil {
		if parent, parentErr := h.repoSvc.GetByID(c.UserContext(), *r.ForkedFromRepoID); parentErr == nil && parent != nil {
			newFork = parent
		}
	}

	fork, err := h.repoSvc.Fork(c.UserContext(), newFork, u, name)
	if err != nil {
		h.setFlashT(c, "flash.fork_failed", err.Error())
		return c.Redirect(fmt.Sprintf("/%s/%s", r.OwnerUsername, r.Name), fiber.StatusSeeOther)
	}

	h.setFlashT(c, "flash.fork_created")
	return c.Redirect(fmt.Sprintf("/%s/%s", fork.OwnerUsername, fork.Name), fiber.StatusSeeOther)
}

// RepoForksPage lists all forks of the repository.
func (h *Handler) RepoForksPage(c *fiber.Ctx) error {
	r, _, err := h.loadAuthorizedRepo(c, false)
	if err != nil {
		return nil
	}

	forks, _ := h.repoSvc.ListForks(c.UserContext(), r.ID, 100)

	var upstream map[string]string
	if r.ForkedFromRepoID != nil {
		upstream = map[string]string{"Owner": r.ForkedFromOwner, "Name": r.ForkedFromName}
	}

	viewer := middleware.CurrentUser(c)
	data := h.baseData(c, h.tr(c, "forks.title")+" · "+r.OwnerUsername+"/"+r.Name)
	data["Repo"] = r
	data["Ref"] = r.DefaultBranch
	data["ActiveTab"] = "code"
	data["CanWrite"] = h.repoSvc.CanWrite(c.UserContext(), r, viewer)
	data["CloneURL"] = h.cloneURL(c, r.OwnerUsername, r.Name)
	data["Forks"] = forks
	data["Upstream"] = upstream

	return h.render(c, fiber.StatusOK, "forks", data)
}