package cli

import (
	"fmt"
	"text/tabwriter"
	"time"

	"github.com/spf13/cobra"

	"gitea.mynodes.xyz/ilker/llmgw/internal/account"
	"gitea.mynodes.xyz/ilker/llmgw/internal/store"
)

func newUsersCmd() *cobra.Command {
	var sf storeFlags

	cmd := &cobra.Command{
		Use:   "users",
		Short: "Approve and manage the people who sign up",
		Long: "Signing up creates an account that cannot do anything. Approval is what\n" +
			"makes it work, and it happens here rather than in a browser: approving is\n" +
			"the step that decides who gets to spend the cluster, and it needs a shell\n" +
			"on this machine rather than a session cookie.",
	}
	sf.bind(cmd)
	open := func(cmd *cobra.Command) (*store.DB, error) {
		return sf.open(cmd)
	}

	cmd.AddCommand(newUserListCmd(open), newUserApproveCmd(open),
		newUserStateCmd(open, "suspend", store.UserSuspended,
			"Stop an account working, keeping it and its history"),
		newUserStateCmd(open, "reinstate", store.UserActive,
			"Let a suspended account work again"),
		newUserCreateCmd(open), newUserResetPasswordCmd(open),
		newUserAdminCmd(open, "promote", true, "Let an account see the cluster dashboard at /admin"),
		newUserAdminCmd(open, "demote", false, "Take away access to the cluster dashboard"))
	return cmd
}

type userOpener func(*cobra.Command) (*store.DB, error)

func newUserListCmd(open userOpener) *cobra.Command {
	var pending bool
	cmd := &cobra.Command{
		Use:   "list",
		Short: "List accounts",
		Args:  cobra.NoArgs,
		RunE: func(cmd *cobra.Command, _ []string) error {
			s, err := open(cmd)
			if err != nil {
				return err
			}
			defer s.Close()

			state := store.UserState("")
			if pending {
				state = store.UserPending
			}
			users, err := s.Users(cmd.Context(), state)
			if err != nil {
				return err
			}
			if len(users) == 0 {
				fmt.Fprintln(cmd.OutOrStdout(), "no accounts")
				return nil
			}

			w := tabwriter.NewWriter(cmd.OutOrStdout(), 0, 0, 2, ' ', 0)
			fmt.Fprintln(w, "ID\tEMAIL\tNAME\tSTATE\tADMIN\tPROJECT\tSIGNED UP\tLAST LOGIN")
			now := time.Now()
			for _, u := range users {
				admin := "-"
				if u.IsAdmin {
					admin = "yes"
				}
				fmt.Fprintf(w, "%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\n",
					u.ID, u.Email, u.Name, u.State, admin, dash(u.ProjectID),
					ago(u.CreatedAt, now), ago(u.LastLoginAt, now))
			}
			return w.Flush()
		},
	}
	cmd.Flags().BoolVar(&pending, "pending", false, "only accounts waiting for approval")
	return cmd
}

func newUserApproveCmd(open userOpener) *cobra.Command {
	var project, by string
	cmd := &cobra.Command{
		Use:   "approve <user-id>",
		Short: "Let an account sign in and issue its own keys",
		Long: "The project is required: it decides which limits this person's keys\n" +
			"inherit. An account approved into no project would pass every check and\n" +
			"then fail at the first key it tried to make.",
		Args: cobra.ExactArgs(1),
		RunE: func(cmd *cobra.Command, args []string) error {
			s, err := open(cmd)
			if err != nil {
				return err
			}
			defer s.Close()

			if err := s.ApproveUser(cmd.Context(), args[0], project, by, time.Now()); err != nil {
				return fmt.Errorf("approving %s: %w", args[0], err)
			}
			u, err := s.UserByID(cmd.Context(), args[0])
			if err != nil {
				return err
			}
			fmt.Fprintf(cmd.OutOrStdout(), "%s approved into project %s\n", u.Email, project)
			cmd.PrintErrln("They can sign in and create their own keys from /profile.")
			return nil
		},
	}
	cmd.Flags().StringVar(&project, "project", "default", "project the person's keys belong to")
	cmd.Flags().StringVar(&by, "by", "", "who approved, for the record")
	_ = cmd.MarkFlagRequired("project")
	return cmd
}

func newUserStateCmd(open userOpener, verb string, state store.UserState, short string) *cobra.Command {
	return &cobra.Command{
		Use:   verb + " <user-id>",
		Short: short,
		Args:  cobra.ExactArgs(1),
		RunE: func(cmd *cobra.Command, args []string) error {
			s, err := open(cmd)
			if err != nil {
				return err
			}
			defer s.Close()

			if err := s.SetUserState(cmd.Context(), args[0], state); err != nil {
				return err
			}
			if state == store.UserSuspended {
				// Otherwise the person stays signed in and suspension is
				// advisory until their session happens to expire.
				if err := s.DeleteUserSessions(cmd.Context(), args[0]); err != nil {
					return err
				}
				cmd.PrintErrln("Their sessions were closed. Their API keys still work — revoke those separately.")
			}
			fmt.Fprintf(cmd.OutOrStdout(), "%s is now %s\n", args[0], state)
			return nil
		},
	}
}

func newUserAdminCmd(open userOpener, verb string, admin bool, short string) *cobra.Command {
	return &cobra.Command{
		Use:   verb + " <user-id>",
		Short: short,
		Long: "The dashboard is read-only, so this grants looking and nothing else.\n" +
			"Everything that changes the cluster or issues a credential stays here on\n" +
			"the CLI, where it needs a shell rather than a session — which keeps the\n" +
			"worst case of a stolen admin cookie to \"saw the cluster\".",
		Args: cobra.ExactArgs(1),
		RunE: func(cmd *cobra.Command, args []string) error {
			s, err := open(cmd)
			if err != nil {
				return err
			}
			defer s.Close()

			if err := s.SetAdmin(cmd.Context(), args[0], admin); err != nil {
				return err
			}
			u, err := s.UserByID(cmd.Context(), args[0])
			if err != nil {
				return err
			}
			if admin {
				fmt.Fprintf(cmd.OutOrStdout(), "%s can now see /admin\n", u.Email)
			} else {
				fmt.Fprintf(cmd.OutOrStdout(), "%s can no longer see /admin\n", u.Email)
				cmd.PrintErrln("Their session stays open; the page is read-only. " +
					"Suspend the account to close it.")
			}
			return nil
		},
	}
}

func newUserResetPasswordCmd(open userOpener) *cobra.Command {
	var password string
	cmd := &cobra.Command{
		Use:   "reset-password <user-id>",
		Short: "Set a new password for someone who lost theirs",
		Long: "There is no self-service reset, because this gateway sends no email and\n" +
			"a reset link with nowhere to send it is not a reset. Set one here, tell\n" +
			"them out of band, and have them change it from their profile.\n\n" +
			"Every session they have open is closed: if they lost the password, the\n" +
			"reason might be that somebody else has it.",
		Args: cobra.ExactArgs(1),
		RunE: func(cmd *cobra.Command, args []string) error {
			if password == "" {
				return fmt.Errorf("--password is required")
			}
			s, err := open(cmd)
			if err != nil {
				return err
			}
			defer s.Close()

			hash, err := account.HashPassword(password)
			if err != nil {
				return err
			}
			if err := s.SetPassword(cmd.Context(), args[0], hash); err != nil {
				return err
			}
			if err := s.DeleteUserSessions(cmd.Context(), args[0]); err != nil {
				return err
			}
			fmt.Fprintf(cmd.OutOrStdout(), "password set for %s\n", args[0])
			cmd.PrintErrln("Their sessions were closed. Their API keys still work.")
			return nil
		},
	}
	cmd.Flags().StringVar(&password, "password", "", "the new password")
	return cmd
}

func newUserCreateCmd(open userOpener) *cobra.Command {
	var project, password string
	cmd := &cobra.Command{
		Use:   "create <email>",
		Short: "Create an account directly, already approved",
		Long: "For when signup is closed, or for the first account on a new deployment.\n" +
			"The password is set here and should be changed by its owner.",
		Args: cobra.ExactArgs(1),
		RunE: func(cmd *cobra.Command, args []string) error {
			if password == "" {
				return fmt.Errorf("--password is required")
			}
			s, err := open(cmd)
			if err != nil {
				return err
			}
			defer s.Close()

			hash, err := account.HashPassword(password)
			if err != nil {
				return err
			}
			id := randomID("usr")
			u := store.User{
				ID: id, Email: args[0], Name: args[0],
				PasswordHash: hash, State: store.UserPending, CreatedAt: time.Now(),
			}
			if err := s.CreateUser(cmd.Context(), u); err != nil {
				return err
			}
			if err := s.ApproveUser(cmd.Context(), id, project, "cli", time.Now()); err != nil {
				return err
			}
			fmt.Fprintf(cmd.OutOrStdout(), "%s\n", id)
			cmd.PrintErrf("%s created and approved into project %s\n", args[0], project)
			return nil
		},
	}
	cmd.Flags().StringVar(&project, "project", "default", "project the person's keys belong to")
	cmd.Flags().StringVar(&password, "password", "", "initial password")
	return cmd
}