// Copyright (c) 2025-2026 Probo Inc <hello@probo.com>.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

//go:generate go tool github.com/99designs/gqlgen generate

package console_v1

import (
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"net/url"

	"github.com/go-chi/chi/v5"
	"go.gearno.de/kit/httpserver"
	"go.gearno.de/kit/log"
	"go.probo.inc/probo/pkg/accessreview"
	"go.probo.inc/probo/pkg/agentrun"
	"go.probo.inc/probo/pkg/baseurl"
	"go.probo.inc/probo/pkg/certmanager"
	"go.probo.inc/probo/pkg/complianceportal/management"
	"go.probo.inc/probo/pkg/connector"
	"go.probo.inc/probo/pkg/connector/provider"
	"go.probo.inc/probo/pkg/cookiebanner"
	"go.probo.inc/probo/pkg/coredata"
	"go.probo.inc/probo/pkg/esign"
	"go.probo.inc/probo/pkg/filemanager"
	"go.probo.inc/probo/pkg/gid"
	"go.probo.inc/probo/pkg/iam"
	"go.probo.inc/probo/pkg/itam"
	"go.probo.inc/probo/pkg/mailman"
	"go.probo.inc/probo/pkg/probo"
	"go.probo.inc/probo/pkg/resourcealias"
	"go.probo.inc/probo/pkg/riskmanagement"
	"go.probo.inc/probo/pkg/saferedirect"
	"go.probo.inc/probo/pkg/securecookie"
	"go.probo.inc/probo/pkg/server/api/authn"
	"go.probo.inc/probo/pkg/server/api/authz"
	"go.probo.inc/probo/pkg/server/api/console/v1/dataloader"
	"go.probo.inc/probo/pkg/server/api/console/v1/types"
	"go.probo.inc/probo/pkg/server/gqlutils"
	"go.probo.inc/probo/pkg/thirdparty"
)

type (
	Resolver struct {
		authorize         authz.AuthorizeFunc
		batchAuthorize    authz.BatchAuthorizeFunc
		probo             *probo.Service
		resourceAlias     *resourcealias.Service
		iam               *iam.Service
		esign             *esign.Service
		management        *management.Service
		certManager       *certmanager.Service
		accessReview      *accessreview.Service
		agentRun          *agentrun.Service
		mailman           *mailman.Service
		cookieBanner      *cookiebanner.Service
		connectorRegistry *connector.ConnectorRegistry
		providerRegistry  *provider.Registry
		riskManagement    *riskmanagement.Service
		thirdParty        *thirdparty.Service
		itam              *itam.Service
		logger            *log.Logger
		fileManager       *filemanager.Service
		baseURL           *baseurl.BaseURL
		customDomainCname string
		tokenSecret       string
	}
)

func NewMux(
	logger *log.Logger,
	proboSvc *probo.Service,
	resourceAliasSvc *resourcealias.Service,
	iamSvc *iam.Service,
	esignSvc *esign.Service,
	managementSvc *management.Service,
	certManagerSvc *certmanager.Service,
	accessReviewSvc *accessreview.Service,
	agentRunSvc *agentrun.Service,
	mailmanSvc *mailman.Service,
	cookieBannerSvc *cookiebanner.Service,
	cookieConfig securecookie.Config,
	tokenSecret string,
	connectorRegistry *connector.ConnectorRegistry,
	providerRegistry *provider.Registry,
	fileManagerSvc *filemanager.Service,
	baseURL *baseurl.BaseURL,
	customDomainCname string,
	thirdPartySvc *thirdparty.Service,
	riskManagementSvc *riskmanagement.Service,
	graphqlLimits gqlutils.Limits,
	itamSvc *itam.Service,
) *chi.Mux {
	r := chi.NewMux()

	safeRedirect := saferedirect.New(saferedirect.StaticHosts(baseURL.Host()))

	graphqlHandler := NewGraphQLHandler(
		iamSvc,
		proboSvc,
		resourceAliasSvc,
		esignSvc,
		managementSvc,
		certManagerSvc,
		accessReviewSvc,
		agentRunSvc,
		mailmanSvc,
		cookieBannerSvc,
		connectorRegistry,
		providerRegistry,
		customDomainCname,
		tokenSecret,
		logger,
		thirdPartySvc,
		riskManagementSvc,
		fileManagerSvc,
		baseURL,
		graphqlLimits,
		itamSvc,
	)

	r.Group(func(r chi.Router) {
		r.Use(authn.NewSessionMiddleware(iamSvc, cookieConfig))
		r.Use(authn.NewAPIKeyMiddleware(iamSvc, tokenSecret))
		r.Use(authn.NewOAuth2AccessTokenMiddleware(iamSvc))
		r.Use(authn.NewIdentityPresenceMiddleware(baseURL))
		r.Use(dataloader.NewMiddleware(proboSvc, iamSvc, cookieBannerSvc, thirdPartySvc))

		r.Handle("/graphql", graphqlHandler)

		r.Get(
			"/connectors/initiate",
			handleConnectorInitiate(logger, proboSvc, iamSvc, connectorRegistry),
		)

		r.Get(
			"/connectors/complete",
			handleConnectorComplete(
				logger,
				baseURL,
				proboSvc,
				accessReviewSvc,
				connectorRegistry,
				safeRedirect,
			),
		)
	})

	// Public, unauthenticated: the OAuth Client ID Metadata Document (CIMD)
	// is fetched server-to-server by public-client providers (PostHog)
	// during authorization, with no Probo credentials. Mounted outside the
	// auth group above.
	r.Get("/connectors/oauth-client-metadata", handleConnectorOAuth2ClientMetadata(baseURL))

	return r
}

func handleConnectorComplete(
	logger *log.Logger,
	baseURL *baseurl.BaseURL,
	proboSvc *probo.Service,
	accessReviewSvc *accessreview.Service,
	connectorRegistry *connector.ConnectorRegistry,
	safeRedirect *saferedirect.SafeRedirect,
) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		query := r.URL.Query()

		if oauthErr := query.Get("error"); oauthErr != "" {
			handleConnectorOAuth2Error(w, r, logger, baseURL, safeRedirect, query)
			return
		}

		stateToken := query.Get("state")
		if stateToken == "" {
			httpserver.RenderError(w, http.StatusBadRequest, fmt.Errorf("missing state parameter"))
			return
		}

		provider, err := connector.ExtractProviderFromState(stateToken)
		if err != nil {
			httpserver.RenderError(w, http.StatusBadRequest, fmt.Errorf("cannot extract provider from state: %w", err))
			return
		}

		var connectorProvider coredata.ConnectorProvider
		if err := connectorProvider.UnmarshalText([]byte(provider)); err != nil {
			httpserver.RenderError(w, http.StatusBadRequest, fmt.Errorf("unsupported provider: %q", provider))
			return
		}

		connection, state, err := connectorRegistry.CompleteWithState(r.Context(), provider, r)
		if err != nil {
			logger.ErrorCtx(r.Context(), "cannot complete connector", log.Error(err))
			httpserver.RenderError(w, http.StatusInternalServerError, fmt.Errorf("internal error"))

			return
		}

		organizationID, err := gid.ParseGID(state.OrganizationID)
		if err != nil {
			httpserver.RenderError(w, http.StatusBadRequest, fmt.Errorf("cannot parse organization ID from state: %w", err))
			return
		}

		scope := coredata.NewScopeFromObjectID(organizationID)
		svc := proboSvc

		var cnnctr *coredata.Connector

		// Some providers persist per-customer settings on the connector,
		// captured here for both the create and the reconnect path: Datadog
		// echoes its API domain as a `domain` callback param; Zendesk's
		// subdomain rode the signed OAuth state from initiate (it is not
		// echoed back). Both become a URL host, so each is re-validated
		// before use. At most one block applies per callback.
		var rawSettings json.RawMessage

		if connectorProvider == coredata.ConnectorProviderDatadog {
			domain := query.Get("domain")
			if !connector.IsValidDatadogDomain(domain) {
				logger.WarnCtx(r.Context(), "rejecting invalid datadog domain",
					log.String("provider", string(connectorProvider)),
				)
				httpserver.RenderError(w, http.StatusBadRequest, fmt.Errorf("invalid domain"))

				return
			}

			region, _ := connector.DatadogSiteForDomain(domain)

			raw, err := json.Marshal(&coredata.DatadogConnectorSettings{
				Region: region,
				Domain: domain,
			})
			if err != nil {
				logger.ErrorCtx(r.Context(), "cannot marshal datadog settings", log.Error(err))
				httpserver.RenderError(w, http.StatusInternalServerError, fmt.Errorf("internal error"))

				return
			}

			rawSettings = raw
		}

		if connectorProvider == coredata.ConnectorProviderZendesk {
			// The subdomain is HMAC-signed in the state (untamperable) and was
			// validated at initiate, but re-validate it here too — it becomes
			// a URL host on every API call (defense-in-depth).
			if !connector.IsValidZendeskSubdomain(state.Site) {
				logger.WarnCtx(r.Context(), "rejecting invalid zendesk subdomain",
					log.String("provider", string(connectorProvider)),
				)
				httpserver.RenderError(w, http.StatusBadRequest, fmt.Errorf("invalid subdomain"))

				return
			}

			raw, err := json.Marshal(&coredata.ZendeskConnectorSettings{
				Subdomain: state.Site,
			})
			if err != nil {
				logger.ErrorCtx(r.Context(), "cannot marshal zendesk settings", log.Error(err))
				httpserver.RenderError(w, http.StatusInternalServerError, fmt.Errorf("internal error"))

				return
			}

			rawSettings = raw
		}

		// If a connector_id was passed in the state, this is a
		// reconnection — update the existing connector's token.
		if state.ConnectorID != "" {
			connectorID, err := gid.ParseGID(state.ConnectorID)
			if err != nil {
				httpserver.RenderError(w, http.StatusBadRequest, fmt.Errorf("cannot parse connector ID from state: %w", err))
				return
			}

			cnnctr, err = svc.Connectors.Reconnect(
				r.Context(),
				scope,
				probo.ReconnectConnectorRequest{
					ConnectorID:    connectorID,
					OrganizationID: organizationID,
					Provider:       connectorProvider,
					Connection:     connection,
					RawSettings:    rawSettings,
				},
			)
			if err != nil {
				logger.ErrorCtx(r.Context(), "cannot reconnect connector", log.Error(err))
				httpserver.RenderError(w, http.StatusInternalServerError, fmt.Errorf("internal error"))

				return
			}

			// The reconnect may carry a different scope/org, changing the
			// resolvable instance name. Clear the synced-name flag so the
			// source-name worker re-resolves it. Best-effort: a failure here
			// must not fail the OAuth callback redirect.
			if err := accessReviewSvc.ResetSourceNameSyncForConnector(r.Context(), scope, cnnctr.ID); err != nil {
				logger.WarnCtx(r.Context(), "cannot reset access source name sync after reconnect", log.Error(err))
			}
		} else {
			createReq := probo.CreateConnectorRequest{
				OrganizationID: organizationID,
				Provider:       connectorProvider,
				Protocol:       coredata.ConnectorProtocol(connection.Type()),
				Connection:     connection,
			}

			// PagerDuty Scoped OAuth surfaces the customer's subdomain as
			// a `subdomain` query parameter on the redirect URL (not in
			// the token response body). Persist it on the connector
			// settings so the driver and name resolver can read it.
			if connectorProvider == coredata.ConnectorProviderPagerDuty {
				subdomain := query.Get("subdomain")
				if subdomain == "" {
					// Fall back to ProviderMetadata for older OAuth flows
					// that may have surfaced the subdomain through the
					// token response body.
					subdomain = state.ProviderMetadata["subdomain"]
				}

				// The subdomain comes from an attacker-influenceable
				// callback parameter; refuse anything that isn't a valid
				// DNS label so it cannot be smuggled into URLs or logs.
				if subdomain != "" && !isValidPagerDutySubdomain(subdomain) {
					logger.WarnCtx(r.Context(), "rejecting invalid pagerduty subdomain",
						log.String("provider", string(connectorProvider)),
					)

					subdomain = ""
				}

				if subdomain != "" {
					raw, err := json.Marshal(&coredata.PagerDutyConnectorSettings{
						Subdomain: subdomain,
					})
					if err != nil {
						logger.ErrorCtx(r.Context(), "cannot marshal pagerduty settings", log.Error(err))
						httpserver.RenderError(w, http.StatusInternalServerError, fmt.Errorf("internal error"))

						return
					}

					createReq.RawSettings = raw
				}
			}

			// Personal-account installs send no teamId; fall back to
			// /v2/user.id as a synthetic TeamID (the v3 members endpoint
			// accepts personal-account UIDs).
			if connectorProvider == coredata.ConnectorProviderVercel {
				teamID := vercelCallbackTeamID(query)
				if teamID == "" {
					if oauth2Conn, ok := connection.(*connector.OAuth2Connection); ok && oauth2Conn.AccessToken != "" {
						if uid, err := connector.FetchVercelUserID(r.Context(), oauth2Conn.AccessToken); err == nil {
							teamID = uid
						} else {
							logger.WarnCtx(r.Context(), "cannot fetch vercel user id for personal-account fallback", log.Error(err))
						}
					}
				}

				if teamID != "" {
					raw, err := json.Marshal(&coredata.VercelConnectorSettings{
						TeamID: teamID,
					})
					if err != nil {
						logger.ErrorCtx(r.Context(), "cannot marshal vercel settings", log.Error(err))
						httpserver.RenderError(w, http.StatusInternalServerError, fmt.Errorf("internal error"))

						return
					}

					createReq.RawSettings = raw
				}
			}

			// Per-customer settings captured above (Datadog's callback domain
			// or Zendesk's state subdomain) apply to the create request; at
			// most one provider populates them per callback.
			if rawSettings != nil {
				createReq.RawSettings = rawSettings
			}

			cnnctr, err = svc.Connectors.Create(r.Context(), scope, createReq)
			if err != nil {
				logger.ErrorCtx(r.Context(), "cannot create connector", log.Error(err))
				httpserver.RenderError(w, http.StatusInternalServerError, fmt.Errorf("internal error"))

				return
			}
		}

		redirectURL := state.ContinueURL
		if redirectURL == "" {
			redirectURL = baseURL.WithPath("/organizations/" + organizationID.String()).MustString()
		}

		parsedURL, err := url.Parse(redirectURL)
		if err != nil {
			logger.ErrorCtx(r.Context(), "cannot parse redirect URL", log.Error(err))

			parsedURL, _ = url.Parse(baseURL.WithPath("/organizations/" + organizationID.String()).MustString())
		}

		q := parsedURL.Query()
		q.Set("connector_id", cnnctr.ID.String())
		q.Set("provider", string(connectorProvider))
		parsedURL.RawQuery = q.Encode()

		safeRedirect.Redirect(w, r, parsedURL.String(), "/", http.StatusSeeOther)
	}
}

func handleConnectorOAuth2Error(
	w http.ResponseWriter,
	r *http.Request,
	logger *log.Logger,
	baseURL *baseurl.BaseURL,
	safeRedirect *saferedirect.SafeRedirect,
	query url.Values,
) {
	oauthErr := query.Get("error")

	provider := "unknown"
	redirectURL := baseURL.String()

	if stateToken := query.Get("state"); stateToken != "" {
		if payload, err := connector.DecodeOAuth2StatePayload(stateToken); err == nil {
			if payload.Data.Provider != "" {
				provider = payload.Data.Provider
			}

			if payload.Data.ContinueURL != "" {
				redirectURL = payload.Data.ContinueURL
			}
		}
	}

	// Provider error_description fields routinely carry PII (user emails,
	// account names) and must never reach logs or the client redirect URL.
	// Forward only the standardized error code.
	logger.WarnCtx(r.Context(), "OAuth2 callback returned error",
		log.String("provider", provider),
		log.String("error", oauthErr),
	)

	parsedURL, _ := url.Parse(redirectURL)
	q := parsedURL.Query()
	q.Set("error", oauthErr)
	parsedURL.RawQuery = q.Encode()

	safeRedirect.Redirect(w, r, parsedURL.String(), "/", http.StatusSeeOther)
}

// vercelCallbackTeamID returns the team identifier from Vercel's OAuth
// callback. Vercel uses the camelCase `teamId` query param (not snake_case
// `team_id`); the name is pinned by a test so it cannot silently regress.
func vercelCallbackTeamID(query url.Values) string {
	return query.Get("teamId")
}

// isValidPagerDutySubdomain reports whether s is a single DNS label
// (RFC 1035 §2.3.1). PagerDuty subdomains are tenant identifiers that
// will be embedded in API URLs; the OAuth callback is the only place
// where a malformed value can enter the system.
func isValidPagerDutySubdomain(s string) bool {
	if s == "" || len(s) > 63 {
		return false
	}

	for _, c := range s {
		switch {
		case c >= 'a' && c <= 'z':
		case c >= 'A' && c <= 'Z':
		case c >= '0' && c <= '9':
		case c == '-':
		default:
			return false
		}
	}

	return true
}

func (r *Resolver) Permission(ctx context.Context, obj types.Node, action string) (bool, error) {
	_, err := r.authorize(ctx, obj.GetID(), action, authz.WithDryRun())

	return err == nil, nil
}