package client

import (
	"context"
	"net/http"
	"net/url"
	"time"
)

// Group is a node of the server's group tree as the client sees it.
type Group struct {
	ID       string `json:"id"`
	Name     string `json:"name"`
	ParentID string `json:"parent_id"`
	Admin    bool   `json:"admin"`
	Members  int    `json:"members"`
}

// Invite is a registration link.
type Invite struct {
	Token     string    `json:"token"`
	URL       string    `json:"url"`
	GroupID   string    `json:"group_id"`
	Role      string    `json:"role"`
	Uses      int       `json:"uses"`
	MaxUses   int       `json:"max_uses"`
	ExpiresAt time.Time `json:"expires_at"`
}

// User is an account as an administrator sees it.
type User struct {
	ID          string `json:"id"`
	Username    string `json:"username"`
	Email       string `json:"email"`
	ServerAdmin bool   `json:"server_admin"`
	TOTPEnabled bool   `json:"totp_enabled"`
}

// Identity is the answer to "who am I and where do I belong".
type Identity struct {
	User
	Groups []struct {
		ID   string `json:"id"`
		Name string `json:"name"`
		Role string `json:"role"`
	} `json:"groups"`
}

func (a *API) Whoami(ctx context.Context) (*Identity, error) {
	var out Identity
	return &out, a.do(ctx, http.MethodGet, "/api/v1/auth/whoami", nil, &out)
}

func (a *API) Groups(ctx context.Context) ([]Group, error) {
	var out struct {
		Groups []Group `json:"groups"`
	}
	err := a.do(ctx, http.MethodGet, "/api/v1/groups", nil, &out)
	return out.Groups, err
}

func (a *API) CreateGroup(ctx context.Context, name, parentID string) (*Group, error) {
	var out Group
	return &out, a.do(ctx, http.MethodPost, "/api/v1/groups",
		map[string]string{"name": name, "parent_id": parentID}, &out)
}

func (a *API) DeleteGroup(ctx context.Context, id string) error {
	return a.do(ctx, http.MethodDelete, "/api/v1/groups/"+url.PathEscape(id), nil, nil)
}

func (a *API) SetMember(ctx context.Context, groupID, username, role string) error {
	return a.do(ctx, http.MethodPost,
		"/api/v1/groups/"+url.PathEscape(groupID)+"/members",
		map[string]string{"username": username, "role": role}, nil)
}

func (a *API) RemoveMember(ctx context.Context, groupID, user string) error {
	return a.do(ctx, http.MethodDelete,
		"/api/v1/groups/"+url.PathEscape(groupID)+"/members/"+url.PathEscape(user), nil, nil)
}

func (a *API) CreateDatabase(ctx context.Context, name, groupID, strategy string) (*Database, error) {
	body := map[string]string{"name": name, "owner_group_id": groupID}
	if strategy != "" {
		body["merge_strategy"] = strategy
	}
	var out Database
	return &out, a.do(ctx, http.MethodPost, "/api/v1/databases", body, &out)
}

// SetStrategy changes the merge strategy of a database. Only an
// administrator of the owning group may do this.
func (a *API) SetStrategy(ctx context.Context, dbID, strategy string) (*Database, error) {
	var out Database
	return &out, a.do(ctx, http.MethodPatch, "/api/v1/databases/"+url.PathEscape(dbID),
		map[string]string{"merge_strategy": strategy}, &out)
}

func (a *API) RenameDatabase(ctx context.Context, dbID, name string) (*Database, error) {
	var out Database
	return &out, a.do(ctx, http.MethodPatch, "/api/v1/databases/"+url.PathEscape(dbID),
		map[string]string{"name": name}, &out)
}

// DeleteDatabase removes a database and every version of it stored on the
// server. The caller's own account password is required, and the one-time
// code too when that account has one enrolled; the server answers
// totp_required when it is missing.
func (a *API) DeleteDatabase(ctx context.Context, dbID, password, totp string) error {
	return a.do(ctx, http.MethodDelete, "/api/v1/databases/"+url.PathEscape(dbID),
		map[string]string{"password": password, "totp": totp}, nil)
}

func (a *API) SetGrant(ctx context.Context, groupID, dbID, perm string) error {
	return a.do(ctx, http.MethodPost, "/api/v1/grants",
		map[string]string{"group_id": groupID, "database_id": dbID, "perm": perm}, nil)
}

func (a *API) DeleteGrant(ctx context.Context, groupID, dbID string) error {
	q := url.Values{"group_id": {groupID}, "database_id": {dbID}}
	return a.do(ctx, http.MethodDelete, "/api/v1/grants?"+q.Encode(), nil, nil)
}

func (a *API) CreateInvite(ctx context.Context, groupID, role string, ttlHours, maxUses int) (*Invite, error) {
	var out Invite
	return &out, a.do(ctx, http.MethodPost, "/api/v1/invites", map[string]any{
		"group_id": groupID, "role": role, "ttl_hours": ttlHours, "max_uses": maxUses}, &out)
}

func (a *API) Invites(ctx context.Context) ([]Invite, error) {
	var out struct {
		Invites []Invite `json:"invites"`
	}
	err := a.do(ctx, http.MethodGet, "/api/v1/invites", nil, &out)
	return out.Invites, err
}

func (a *API) Users(ctx context.Context) ([]User, error) {
	var out struct {
		Users []User `json:"users"`
	}
	err := a.do(ctx, http.MethodGet, "/api/v1/users", nil, &out)
	return out.Users, err
}

// ChangePassword replaces the account password. The server requires the
// current one, and the second factor when one is enrolled, then signs out
// this account's other sessions.
func (a *API) ChangePassword(ctx context.Context, current, next, totp string) error {
	return a.do(ctx, http.MethodPost, "/api/v1/auth/password", map[string]string{
		"current_password": current, "new_password": next, "totp": totp}, nil)
}

// EnrollTOTP starts second-factor enrolment and returns the shared secret
// and its otpauth URI. It needs the account password, and the current code
// when a second factor is already on and is being replaced.
func (a *API) EnrollTOTP(ctx context.Context, password, code string) (secret, uri string, err error) {
	var out struct {
		Secret string `json:"secret"`
		URI    string `json:"uri"`
	}
	err = a.do(ctx, http.MethodPost, "/api/v1/auth/totp/enroll",
		map[string]string{"password": password, "totp": code}, &out)
	return out.Secret, out.URI, err
}

// ConfirmTOTP completes enrolment by proving the secret was stored.
func (a *API) ConfirmTOTP(ctx context.Context, code string) error {
	return a.do(ctx, http.MethodPost, "/api/v1/auth/totp/confirm",
		map[string]string{"code": code}, nil)
}

// CreateVault asks the server to create a new, empty KDBX vault encrypted
// with this password. For the merge strategy the server keeps the password,
// wrapped under its master key, because merging means opening the file.
func (a *API) CreateVault(ctx context.Context, name, groupID, strategy, password string) (*Database, error) {
	var out Database
	return &out, a.do(ctx, http.MethodPost, "/api/v1/vaults", map[string]string{
		"name": name, "owner_group_id": groupID,
		"merge_strategy": strategy, "password": password,
	}, &out)
}

// StoreVaultKey gives the server the password of an existing database, so it
// can merge it. The server verifies the password against the stored file
// before accepting it.
func (a *API) StoreVaultKey(ctx context.Context, dbID, password string) error {
	return a.do(ctx, http.MethodPost,
		"/api/v1/databases/"+url.PathEscape(dbID)+"/key",
		map[string]any{"password": password}, nil)
}

// ForgetVaultKey removes the stored password, which also ends any ability to
// merge that database here.
func (a *API) ForgetVaultKey(ctx context.Context, dbID string) error {
	return a.do(ctx, http.MethodPost,
		"/api/v1/databases/"+url.PathEscape(dbID)+"/key",
		map[string]any{"forget": true}, nil)
}