// Package ghx contains a lib/cli/sink extension for GitHub.
package ghx

import (
	"context"
	"fmt"
	"net/http"

	"github.com/google/go-github/v47/github"
	"github.com/shurcooL/githubv4"
	"golang.org/x/oauth2"

	"edge-infra.dev/pkg/lib/cli/rags"
	"edge-infra.dev/pkg/lib/cli/sink"
)

// TODO: use in-memory caching to take advantage of conditional requests in V3
// client. Requires newer version of go-github to get NewClient().WithToken()

type GHX struct {
	V4         *githubv4.Client
	V3         *github.Client
	httpClient *http.Client

	// Optional indicates that the extension isn't necessary for all invocations
	// and that we shouldn't error if the token isn't set.
	Optional bool

	token string
}

func (g *GHX) RegisterFlags(rs *rags.RagSet) {
	rs.Add(&rags.Rag{
		Name:     "github-token",
		Value:    &rags.String{Var: &g.token},
		Usage:    "A GitHub personal access token.",
		Category: "remote file",
		Required: !g.Optional,
	})
}

func (g *GHX) BeforeRun(ctx context.Context, r sink.Run) (context.Context, sink.Run, error) {
	switch {
	case g.token == "" && g.Optional:
		return ctx, r, nil
	case g.token == "":
		// TODO(sink): handle required flags automatically
		return ctx, r, fmt.Errorf("--github-token is required")
	}

	g.httpClient = oauth2.NewClient(ctx, oauth2.StaticTokenSource(
		&oauth2.Token{AccessToken: g.token},
	))
	g.V4 = githubv4.NewClient(g.httpClient)
	g.V3 = github.NewClient(g.httpClient)

	return ctx, r, nil
}