package model

import (
	"encoding/json"
	"time"
)

// Grant gives access to one resource (see internal/auth).
type Grant struct {
	Resource string `json:"resource"` // config, sets, log, audit, *
	Access   string `json:"access"`   // read or write (write implies read)
	// Sets limits a "sets" grant to these dynamic sets (none: all).
	Sets []string `json:"sets,omitempty"`
}

// User is a person or a service account.
type User struct {
	ID           int64      `json:"id"`
	Username     string     `json:"username"`
	PasswordHash string     `json:"-"`
	HasPassword  bool       `json:"has_password"`
	Admin        bool       `json:"admin"`
	Grants       []Grant    `json:"grants"`
	Disabled     bool       `json:"disabled"`
	Comment      string     `json:"comment"`
	CreatedAt    time.Time  `json:"created_at"`
	UpdatedAt    time.Time  `json:"updated_at"`
	LastLoginAt  *time.Time `json:"last_login_at,omitempty"`
}

// Token is an API token. The secret is shown once, when it is made; only
// its hash is stored.
type Token struct {
	ID         int64  `json:"id"`
	UserID     int64  `json:"user_id"`
	Username   string `json:"username,omitempty"`
	Name       string `json:"name"`
	PublicID   string `json:"public_id"`
	SecretHash string `json:"-"`
	// Grants restrict the token to part of its user's permissions; nil
	// means all of them.
	Grants     []Grant    `json:"grants"`
	ExpiresAt  *time.Time `json:"expires_at,omitempty"`
	CreatedAt  time.Time  `json:"created_at"`
	LastUsedAt *time.Time `json:"last_used_at,omitempty"`
	LastUsedIP string     `json:"last_used_ip,omitempty"`
	RevokedAt  *time.Time `json:"revoked_at,omitempty"`
	// RotatedAt is when the token last got a new secret (nil: never).
	RotatedAt *time.Time `json:"rotated_at,omitempty"`
	// After a rotation with a grace period, the previous secret keeps
	// working until PrevExpiresAt.
	PrevSecretHash string     `json:"-"`
	PrevExpiresAt  *time.Time `json:"previous_secret_valid_until,omitempty"`
}

// IssuedAt is when the token's current secret was made: its last
// rotation, or its creation.
func (t *Token) IssuedAt() time.Time {
	if t.RotatedAt != nil {
		return *t.RotatedAt
	}
	return t.CreatedAt
}

// Session is a web UI login.
type Session struct {
	IDHash     string    `json:"-"`
	UserID     int64     `json:"user_id"`
	CSRFToken  string    `json:"-"`
	CreatedAt  time.Time `json:"created_at"`
	ExpiresAt  time.Time `json:"expires_at"`
	LastSeenAt time.Time `json:"last_seen_at"`
	IP         string    `json:"ip"`
	UserAgent  string    `json:"user_agent"`
}

// AuditEvent records an action: logins, users and tokens, changes,
// dynamic set entries.
type AuditEvent struct {
	ID       int64     `json:"id"`
	Time     time.Time `json:"time"`
	UserID   int64     `json:"user_id,omitempty"`
	Username string    `json:"username,omitempty"`
	Auth     string    `json:"auth,omitempty"` // session, token, socket
	TokenID  int64     `json:"token_id,omitempty"`
	IP       string    `json:"ip,omitempty"`
	Action   string    `json:"action"`
	Object   string    `json:"object,omitempty"`
	Result   string    `json:"result"` // success, failure, denied
	Detail   string    `json:"detail,omitempty"`
}

// Change is one object's change: Before is nil for a create, After is nil
// for a delete. Settings have ID 0.
type Change struct {
	Kind   string          `json:"kind"`
	ID     int64           `json:"id"`
	Label  string          `json:"label"`
	Before json.RawMessage `json:"before,omitempty"`
	After  json.RawMessage `json:"after,omitempty"`
}

// Action describes a change in a word.
func (c Change) Action() string {
	switch {
	case c.Before == nil:
		return "create"
	case c.After == nil:
		return "delete"
	}
	return "update"
}

// Inverse is the change that undoes c.
func (c Change) Inverse() Change {
	c.Before, c.After = c.After, c.Before
	return c
}

// HistoryEntry is a saved configuration change.
type HistoryEntry struct {
	ID          int64     `json:"id"`
	Time        time.Time `json:"time"`
	UserID      int64     `json:"user_id,omitempty"`
	Username    string    `json:"username"`
	Via         string    `json:"via"` // web, cli, api
	Description string    `json:"description"`
	Changes     []Change  `json:"changes"`
	// RevertOf is the entry this one undid; RevertedBy the entry that
	// undid this one.
	RevertOf   int64 `json:"revert_of,omitempty"`
	RevertedBy int64 `json:"reverted_by,omitempty"`
}