package xrpc

import (
	"net/http"

	"tangled.org/core/knotserver/vcs"
	xrpcerr "tangled.org/core/xrpc/errors"
)

// PijulChannelListResponse is the response for listing Pijul channels
type PijulChannelListResponse struct {
	Channels []PijulChannel `json:"channels"`
}

// PijulChannel represents a Pijul channel
type PijulChannel struct {
	Name      string `json:"name"`
	IsCurrent bool   `json:"is_current,omitempty"`
}

// RepoChannelList handles the sh.tangled.repo.channelList endpoint
// Kept for backwards compatibility - delegates to the unified Branches interface.
func (x *Xrpc) RepoChannelList(w http.ResponseWriter, r *http.Request) {
	repo := r.URL.Query().Get("repo")
	repoPath, err := x.parseRepoParam(repo)
	if err != nil {
		writeError(w, err.(xrpcerr.XrpcError), http.StatusBadRequest)
		return
	}

	rv, err := vcs.PlainOpen(repoPath)
	if err != nil {
		writeError(w, xrpcerr.NewXrpcError(
			xrpcerr.WithTag("RepoNotFound"),
			xrpcerr.WithMessage("failed to open repository"),
		), http.StatusNotFound)
		return
	}

	branches, err := rv.Branches(nil)
	if err != nil {
		x.Logger.Error("fetching channels", "error", err.Error())
		writeError(w, xrpcerr.NewXrpcError(
			xrpcerr.WithTag("InternalServerError"),
			xrpcerr.WithMessage("failed to list channels"),
		), http.StatusInternalServerError)
		return
	}

	channelList := make([]PijulChannel, len(branches))
	for i, b := range branches {
		channelList[i] = PijulChannel{
			Name:      b.Name,
			IsCurrent: b.IsDefault,
		}
	}

	writeJson(w, PijulChannelListResponse{Channels: channelList})
}

// PijulGetDefaultChannelResponse is the response for getting the default channel
type PijulGetDefaultChannelResponse struct {
	Channel string `json:"channel"`
}

// RepoGetDefaultChannel handles the sh.tangled.repo.getDefaultChannel endpoint
func (x *Xrpc) RepoGetDefaultChannel(w http.ResponseWriter, r *http.Request) {
	repo := r.URL.Query().Get("repo")
	repoPath, err := x.parseRepoParam(repo)
	if err != nil {
		writeError(w, err.(xrpcerr.XrpcError), http.StatusBadRequest)
		return
	}

	rv, err := vcs.PlainOpen(repoPath)
	if err != nil {
		writeError(w, xrpcerr.NewXrpcError(
			xrpcerr.WithTag("RepoNotFound"),
			xrpcerr.WithMessage("failed to open repository"),
		), http.StatusNotFound)
		return
	}

	channel, err := rv.DefaultBranch()
	if err != nil {
		x.Logger.Error("finding default channel", "error", err.Error())
		writeError(w, xrpcerr.NewXrpcError(
			xrpcerr.WithTag("InternalServerError"),
			xrpcerr.WithMessage("failed to find default channel"),
		), http.StatusInternalServerError)
		return
	}

	writeJson(w, PijulGetDefaultChannelResponse{Channel: channel})
}