package clicmd

import (
	"context"
	"errors"
	"flag"
	"fmt"
	"time"

	"github.com/iceBear67/simplepages/api"
	"github.com/iceBear67/simplepages/internal/cliutil"
)

func keyCmd(g *Globals) *cliutil.Command {
	return &cliutil.Command{
		Name:  "key",
		Short: "Manage API keys",
		Sub: []*cliutil.Command{
			keyCreateCmd(g),
			keyListCmd(g),
			keyRevokeCmd(g),
		},
	}
}

func keyCreateCmd(g *Globals) *cliutil.Command {
	var (
		name    string
		admin   bool
		expires string
	)
	return &cliutil.Command{
		Name:  "create",
		Short: "Mint a key",
		Long: "The token is printed once and cannot be retrieved again — the server\n" +
			"stores only its hash. Redirect it straight into a file or a secret\n" +
			"store; do not let it reach a CI log.\n\n" +
			"Without --admin the key is scoped to one project and can do nothing\n" +
			"outside it. Requires an admin key either way.",
		Flags: func(fs *flag.FlagSet) {
			fs.StringVar(&name, "name", "", "`label` recorded with the key, e.g. github-actions")
			fs.BoolVar(&admin, "admin", false, "mint an admin key instead of a project key")
			fs.StringVar(&expires, "expires", "", "expire after this `duration`, e.g. 90d; default never")
		},
		Exec: func(ctx context.Context, args []string) error {
			if err := exactArgs(args, 0, "no arguments"); err != nil {
				return err
			}
			req := api.CreateKeyRequest{Name: name}
			if expires != "" {
				d, err := cliutil.ParseDuration(expires)
				if err != nil {
					return err
				}
				if d <= 0 {
					return errors.New("--expires must be positive")
				}
				// Computed here, sent absolute: a clock difference between this
				// machine and the server then shifts nothing.
				t := time.Now().Add(d).UTC().Truncate(time.Second)
				req.ExpiresAt = &t
			}

			c, err := g.Client()
			if err != nil {
				return err
			}
			var out api.CreateKeyResponse
			if admin {
				out, err = c.CreateAdminKey(ctx, req)
			} else {
				var project string
				if project, err = g.ProjectName(); err != nil {
					return fmt.Errorf("%w, or pass --admin for a server-wide key", err)
				}
				out, err = c.CreateProjectKey(ctx, project, req)
			}
			if err != nil {
				return err
			}

			p, err := g.Printer()
			if err != nil {
				return err
			}
			if p.Format == cliutil.FormatJSON {
				return p.JSON(out)
			}
			// Table format prints the token on a line of its own so it survives
			// a copy-paste and so `pages key create | tail -1` is not tempting.
			if err := keyTable(out.Key).Write(g.Out); err != nil {
				return err
			}
			fmt.Fprintf(g.Out, "\n%s\n", out.Token)
			fmt.Fprintln(g.Err, "this token is shown once and cannot be recovered; store it now")
			return nil
		},
	}
}

func keyListCmd(g *Globals) *cliutil.Command {
	return &cliutil.Command{
		Name:  "list",
		Short: "List keys",
		Long: "With --project, lists that project's keys; a project key may list its\n" +
			"own. Without it, lists every key on the server and requires an admin\n" +
			"key. Secrets are never listed — only key ids.",
		Exec: func(ctx context.Context, args []string) error {
			if err := exactArgs(args, 0, "no arguments"); err != nil {
				return err
			}
			if err := g.Resolve(); err != nil {
				return err
			}
			c, err := g.Client()
			if err != nil {
				return err
			}
			var list api.KeyList
			if g.Project != "" {
				list, err = c.ListProjectKeys(ctx, g.Project)
			} else {
				list, err = c.ListKeys(ctx)
			}
			if err != nil {
				return err
			}
			if list.Keys == nil {
				list.Keys = []api.Key{}
			}
			p, err := g.Printer()
			if err != nil {
				return err
			}
			return p.Print(list, func() *cliutil.Table {
				t := cliutil.NewTable("ID", "SCOPE", "PROJECT", "NAME", "CREATED", "EXPIRES", "LAST USED", "STATE")
				for _, k := range list.Keys {
					t.Row(k.ID, k.Scope, cliutil.Str(k.Project), cliutil.Str(k.Name),
						cliutil.Time(k.CreatedAt), cliutil.TimePtr(k.ExpiresAt),
						cliutil.TimePtr(k.LastUsed), keyState(k))
				}
				return t
			})
		},
	}
}

func keyRevokeCmd(g *Globals) *cliutil.Command {
	var yes bool
	return &cliutil.Command{
		Name:  "revoke",
		Args:  "<key-id>",
		Short: "Revoke a key",
		Long: "Takes effect immediately across the server. The key id is the middle\n" +
			"segment of a token (pgs_<key-id>_<secret>) and is what `key list`\n" +
			"shows. Revoking an already-revoked key succeeds.",
		Flags: func(fs *flag.FlagSet) {
			fs.BoolVar(&yes, "yes", false, "do not ask for confirmation")
		},
		Exec: func(ctx context.Context, args []string) error {
			if err := exactArgs(args, 1, "one key id"); err != nil {
				return err
			}
			id := args[0]
			if !yes {
				if err := cliutil.Confirm(g.In, g.Err, fmt.Sprintf("Revoke key %s?", id)); err != nil {
					return err
				}
			}
			c, err := g.Client()
			if err != nil {
				return err
			}
			if err := c.RevokeKey(ctx, id); err != nil {
				return err
			}
			p, err := g.Printer()
			if err != nil {
				return err
			}
			p.Printf("revoked key %s\n", id)
			return nil
		},
	}
}

// keyState collapses the two timestamps that decide whether a key still works.
func keyState(k api.Key) string {
	switch {
	case k.Revoked():
		return "revoked"
	case k.ExpiresAt != nil && k.ExpiresAt.Before(time.Now()):
		return "expired"
	default:
		return "active"
	}
}

func keyTable(k api.Key) *cliutil.Table {
	t := cliutil.NewTable()
	t.Row("id", k.ID)
	t.Row("scope", k.Scope)
	t.Row("project", cliutil.Str(k.Project))
	t.Row("name", cliutil.Str(k.Name))
	t.Row("created_at", cliutil.Time(k.CreatedAt))
	t.Row("expires_at", cliutil.TimePtr(k.ExpiresAt))
	return t
}