package okta

import (
	"context"
	"fmt"
	"net/url"

	"time"

	"github.com/chrismalek/oktasdk-go/okta"
	"github.com/hashicorp/go-cleanhttp"
	"github.com/hashicorp/vault/logical"
	"github.com/hashicorp/vault/logical/framework"
)

const (
	defaultBaseURL = "okta.com"
	previewBaseURL = "oktapreview.com"
)

func pathConfig(b *backend) *framework.Path {
	return &framework.Path{
		Pattern: `config`,
		Fields: map[string]*framework.FieldSchema{
			"organization": &framework.FieldSchema{
				Type:        framework.TypeString,
				Description: "(DEPRECATED) Okta organization to authenticate against. Use org_name instead.",
			},
			"org_name": &framework.FieldSchema{
				Type:        framework.TypeString,
				Description: "Name of the organization to be used in the Okta API.",
			},
			"token": &framework.FieldSchema{
				Type:        framework.TypeString,
				Description: "(DEPRECATED) Okta admin API token.  Use api_token instead.",
			},
			"api_token": &framework.FieldSchema{
				Type:        framework.TypeString,
				Description: "Okta API key.",
			},
			"base_url": &framework.FieldSchema{
				Type:        framework.TypeString,
				Description: `The base domain to use for the Okta API. When not specified in the configuration, "okta.com" is used.`,
			},
			"production": &framework.FieldSchema{
				Type:        framework.TypeBool,
				Description: `(DEPRECATED) Use base_url.`,
			},
			"ttl": &framework.FieldSchema{
				Type:        framework.TypeDurationSecond,
				Description: `Duration after which authentication will be expired`,
			},
			"max_ttl": &framework.FieldSchema{
				Type:        framework.TypeDurationSecond,
				Description: `Maximum duration after which authentication will be expired`,
			},
			"bypass_okta_mfa": &framework.FieldSchema{
				Type:        framework.TypeBool,
				Description: `When set true, requests by Okta for a MFA check will be bypassed. This also disallows certain status checks on the account, such as whether the password is expired.`,
			},
		},

		Callbacks: map[logical.Operation]framework.OperationFunc{
			logical.ReadOperation:   b.pathConfigRead,
			logical.CreateOperation: b.pathConfigWrite,
			logical.UpdateOperation: b.pathConfigWrite,
		},

		ExistenceCheck: b.pathConfigExistenceCheck,

		HelpSynopsis: pathConfigHelp,
	}
}

// Config returns the configuration for this backend.
func (b *backend) Config(ctx context.Context, s logical.Storage) (*ConfigEntry, error) {
	entry, err := s.Get(ctx, "config")
	if err != nil {
		return nil, err
	}
	if entry == nil {
		return nil, nil
	}

	var result ConfigEntry
	if entry != nil {
		if err := entry.DecodeJSON(&result); err != nil {
			return nil, err
		}
	}

	return &result, nil
}

func (b *backend) pathConfigRead(ctx context.Context, req *logical.Request, d *framework.FieldData) (*logical.Response, error) {
	cfg, err := b.Config(ctx, req.Storage)
	if err != nil {
		return nil, err
	}
	if cfg == nil {
		return nil, nil
	}

	resp := &logical.Response{
		Data: map[string]interface{}{
			"organization":    cfg.Org,
			"org_name":        cfg.Org,
			"ttl":             cfg.TTL.Seconds(),
			"max_ttl":         cfg.MaxTTL.Seconds(),
			"bypass_okta_mfa": cfg.BypassOktaMFA,
		},
	}
	if cfg.BaseURL != "" {
		resp.Data["base_url"] = cfg.BaseURL
	}
	if cfg.Production != nil {
		resp.Data["production"] = *cfg.Production
	}

	if cfg.BypassOktaMFA {
		resp.AddWarning("Okta MFA bypass is configured. In addition to ignoring Okta MFA requests, certain other account statuses will not be seen, such as PASSWORD_EXPIRED. Authentication will succeed in these cases.")
	}

	return resp, nil
}

func (b *backend) pathConfigWrite(ctx context.Context, req *logical.Request, d *framework.FieldData) (*logical.Response, error) {
	cfg, err := b.Config(ctx, req.Storage)
	if err != nil {
		return nil, err
	}

	// Due to the existence check, entry will only be nil if it's a create
	// operation, so just create a new one
	if cfg == nil {
		cfg = &ConfigEntry{}
	}

	org, ok := d.GetOk("org_name")
	if ok {
		cfg.Org = org.(string)
	}
	if cfg.Org == "" {
		org, ok = d.GetOk("organization")
		if ok {
			cfg.Org = org.(string)
		}
	}
	if cfg.Org == "" && req.Operation == logical.CreateOperation {
		return logical.ErrorResponse("org_name is missing"), nil
	}

	token, ok := d.GetOk("api_token")
	if ok {
		cfg.Token = token.(string)
	}
	if cfg.Token == "" {
		token, ok = d.GetOk("token")
		if ok {
			cfg.Token = token.(string)
		}
	}

	baseURLRaw, ok := d.GetOk("base_url")
	if ok {
		baseURL := baseURLRaw.(string)
		_, err = url.Parse(fmt.Sprintf("https://%s,%s", cfg.Org, baseURL))
		if err != nil {
			return logical.ErrorResponse(fmt.Sprintf("Error parsing given base_url: %s", err)), nil
		}
		cfg.BaseURL = baseURL
	}

	// We only care about the production flag when base_url is not set. It is
	// for compatibility reasons.
	if cfg.BaseURL == "" {
		productionRaw, ok := d.GetOk("production")
		if ok {
			production := productionRaw.(bool)
			cfg.Production = &production
		}
	} else {
		// clear out old production flag if base_url is set
		cfg.Production = nil
	}

	bypass, ok := d.GetOk("bypass_okta_mfa")
	if ok {
		cfg.BypassOktaMFA = bypass.(bool)
	}

	ttl, ok := d.GetOk("ttl")
	if ok {
		cfg.TTL = time.Duration(ttl.(int)) * time.Second
	} else if req.Operation == logical.CreateOperation {
		cfg.TTL = time.Duration(d.Get("ttl").(int)) * time.Second
	}

	maxTTL, ok := d.GetOk("max_ttl")
	if ok {
		cfg.MaxTTL = time.Duration(maxTTL.(int)) * time.Second
	} else if req.Operation == logical.CreateOperation {
		cfg.MaxTTL = time.Duration(d.Get("max_ttl").(int)) * time.Second
	}

	jsonCfg, err := logical.StorageEntryJSON("config", cfg)
	if err != nil {
		return nil, err
	}
	if err := req.Storage.Put(ctx, jsonCfg); err != nil {
		return nil, err
	}

	var resp *logical.Response
	if cfg.BypassOktaMFA {
		resp = new(logical.Response)
		resp.AddWarning("Okta MFA bypass is configured. In addition to ignoring Okta MFA requests, certain other account statuses will not be seen, such as PASSWORD_EXPIRED. Authentication will succeed in these cases.")
	}

	return resp, nil
}

func (b *backend) pathConfigExistenceCheck(ctx context.Context, req *logical.Request, d *framework.FieldData) (bool, error) {
	cfg, err := b.Config(ctx, req.Storage)
	if err != nil {
		return false, err
	}

	return cfg != nil, nil
}

// OktaClient creates a basic okta client connection
func (c *ConfigEntry) OktaClient() *okta.Client {
	baseURL := defaultBaseURL
	if c.Production != nil {
		if !*c.Production {
			baseURL = previewBaseURL
		}
	}
	if c.BaseURL != "" {
		baseURL = c.BaseURL
	}

	// We validate config on input and errors are only returned when parsing URLs
	client, _ := okta.NewClientWithDomain(cleanhttp.DefaultClient(), c.Org, baseURL, c.Token)
	return client
}

// ConfigEntry for Okta
type ConfigEntry struct {
	Org           string        `json:"organization"`
	Token         string        `json:"token"`
	BaseURL       string        `json:"base_url"`
	Production    *bool         `json:"is_production,omitempty"`
	TTL           time.Duration `json:"ttl"`
	MaxTTL        time.Duration `json:"max_ttl"`
	BypassOktaMFA bool          `json:"bypass_okta_mfa"`
}

const pathConfigHelp = `
This endpoint allows you to configure the Okta and its
configuration options.

The Okta organization are the characters at the front of the URL for Okta.
Example https://ORG.okta.com
`