package cmd

import (
	"errors"
	"fmt"
	"github.com/urfave/cli/v2"
	"heckel.io/ntfy/auth"
	"heckel.io/ntfy/util"
)

/*

ntfy access                        # Shows access control list
ntfy access phil                   # Shows access for user phil
ntfy access phil mytopic           # Shows access for user phil and topic mytopic
ntfy access phil mytopic rw        # Allow read-write access to mytopic for user phil
ntfy access everyone mytopic rw    # Allow anonymous read-write access to mytopic
ntfy access --reset                # Reset entire access control list
ntfy access --reset phil           # Reset all access for user phil
ntfy access --reset phil mytopic   # Reset access for user phil and topic mytopic

*/

const (
	userEveryone = "everyone"
)

var flagsAccess = append(
	userCommandFlags(),
	&cli.BoolFlag{Name: "reset", Aliases: []string{"r"}, Usage: "reset access for user (and topic)"},
)

var cmdAccess = &cli.Command{
	Name:      "access",
	Usage:     "Grant/revoke access to a topic, or show access",
	UsageText: "ntfy access [USERNAME [TOPIC [PERMISSION]]]",
	Flags:     flagsAccess,
	Before:    initConfigFileInputSource("config", flagsAccess),
	Action:    execUserAccess,
	Category:  categoryServer,
}

func execUserAccess(c *cli.Context) error {
	manager, err := createAuthManager(c)
	if err != nil {
		return err
	}
	username := c.Args().Get(0)
	if username == userEveryone {
		username = auth.Everyone
	}
	topic := c.Args().Get(1)
	perms := c.Args().Get(2)
	reset := c.Bool("reset")
	if reset {
		return resetAccess(c, manager, username, topic)
	} else if perms == "" {
		return showAccess(c, manager, username)
	}
	return changeAccess(c, manager, username, topic, perms)
}

func changeAccess(c *cli.Context, manager auth.Manager, username string, topic string, perms string) error {
	if !util.InStringList([]string{"", "read-write", "rw", "read-only", "read", "ro", "write-only", "write", "wo", "none", "deny"}, perms) {
		return errors.New("permission must be one of: read-write, read-only, write-only, or deny (or the aliases: read, ro, write, wo, none)")
	}
	read := util.InStringList([]string{"read-write", "rw", "read-only", "read", "ro"}, perms)
	write := util.InStringList([]string{"read-write", "rw", "write-only", "write", "wo"}, perms)
	if err := manager.AllowAccess(username, topic, read, write); err != nil {
		return err
	}
	if read && write {
		fmt.Fprintf(c.App.Writer, "Granted read-write access to topic %s\n\n", topic)
	} else if read {
		fmt.Fprintf(c.App.Writer, "Granted read-only access to topic %s\n\n", topic)
	} else if write {
		fmt.Fprintf(c.App.Writer, "Granted write-only access to topic %s\n\n", topic)
	} else {
		fmt.Fprintf(c.App.Writer, "Revoked all access to topic %s\n\n", topic)
	}
	return showUserAccess(c, manager, username)
}

func resetAccess(c *cli.Context, manager auth.Manager, username, topic string) error {
	if username == "" {
		return resetAllAccess(c, manager)
	} else if topic == "" {
		return resetUserAccess(c, manager, username)
	}
	return resetUserTopicAccess(c, manager, username, topic)
}

func resetAllAccess(c *cli.Context, manager auth.Manager) error {
	if err := manager.ResetAccess("", ""); err != nil {
		return err
	}
	fmt.Fprintln(c.App.Writer, "Reset access for all users")
	return nil
}

func resetUserAccess(c *cli.Context, manager auth.Manager, username string) error {
	if err := manager.ResetAccess(username, ""); err != nil {
		return err
	}
	fmt.Fprintf(c.App.Writer, "Reset access for user %s\n\n", username)
	return showUserAccess(c, manager, username)
}

func resetUserTopicAccess(c *cli.Context, manager auth.Manager, username string, topic string) error {
	if err := manager.ResetAccess(username, topic); err != nil {
		return err
	}
	fmt.Fprintf(c.App.Writer, "Reset access for user %s and topic %s\n\n", username, topic)
	return showUserAccess(c, manager, username)
}

func showAccess(c *cli.Context, manager auth.Manager, username string) error {
	if username == "" {
		return showAllAccess(c, manager)
	}
	return showUserAccess(c, manager, username)
}

func showAllAccess(c *cli.Context, manager auth.Manager) error {
	users, err := manager.Users()
	if err != nil {
		return err
	}
	return showUsers(c, manager, users)
}

func showUserAccess(c *cli.Context, manager auth.Manager, username string) error {
	users, err := manager.User(username)
	if err != nil {
		return err
	}
	return showUsers(c, manager, []*auth.User{users})
}

func showUsers(c *cli.Context, manager auth.Manager, users []*auth.User) error {
	for _, user := range users {
		fmt.Fprintf(c.App.Writer, "User %s (%s)\n", user.Name, user.Role)
		if user.Role == auth.RoleAdmin {
			fmt.Fprintf(c.App.ErrWriter, "- read-write access to all topics (admin role)\n")
		} else if len(user.Grants) > 0 {
			for _, grant := range user.Grants {
				if grant.Read && grant.Write {
					fmt.Fprintf(c.App.ErrWriter, "- read-write access to topic %s\n", grant.Topic)
				} else if grant.Read {
					fmt.Fprintf(c.App.ErrWriter, "- read-only access to topic %s\n", grant.Topic)
				} else if grant.Write {
					fmt.Fprintf(c.App.ErrWriter, "- write-only access to topic %s\n", grant.Topic)
				} else {
					fmt.Fprintf(c.App.ErrWriter, "- no access to topic %s\n", grant.Topic)
				}
			}
		} else {
			fmt.Fprintf(c.App.ErrWriter, "- no topic-specific permissions\n")
		}
		if user.Name == auth.Everyone {
			defaultRead, defaultWrite := manager.DefaultAccess()
			if defaultRead && defaultWrite {
				fmt.Fprintln(c.App.ErrWriter, "- read-write access to all (other) topics (server config)")
			} else if defaultRead {
				fmt.Fprintln(c.App.ErrWriter, "- read-only access to all (other) topics (server config)")
			} else if defaultWrite {
				fmt.Fprintln(c.App.ErrWriter, "- write-only access to all (other) topics (server config)")
			} else {
				fmt.Fprintln(c.App.ErrWriter, "- no access to any (other) topics (server config)")
			}
		}
	}
	return nil
}