package handler

// Audit 2026-05-10 MED-11 closure — federated-user admin surface.
//
// GET    /api/v1/auth/users          → gated auth.user.read
// DELETE /api/v1/auth/users/{id}     → gated auth.user.deactivate
//
// The DELETE path is SOFT-DELETE — it sets users.deactivated_at and
// cascade-revokes the user's active sessions in the same operation.
// The row is the OIDC binding (tuple of (oidc_provider_id, oidc_subject));
// destroying it would re-mint a fresh user on the next IdP login under
// the same subject, losing the audit trail.

import (
	"context"
	"errors"
	"net/http"
	"time"

	oidcsvc "github.com/certctl-io/certctl/internal/auth/oidc"
	userdomain "github.com/certctl-io/certctl/internal/auth/user/domain"
	"github.com/certctl-io/certctl/internal/domain"
	"github.com/certctl-io/certctl/internal/repository"
)

// AuthUsersHandler exposes the federated-user admin surface.
type AuthUsersHandler struct {
	users    repository.UserRepository
	sessions UserSessionsRevoker
	audit    AuditRecorder
	tenantID string
}

// UserSessionsRevoker is the slice of *session.Service the user-handler
// uses to cascade-revoke a deactivated user's active sessions in the
// same operation. Nil-safe: when unset (tests without session wiring),
// Deactivate logs an audit row but skips the revoke step.
type UserSessionsRevoker interface {
	RevokeAllForActor(ctx context.Context, actorID, actorType string) error
}

// NewAuthUsersHandler constructs a federated-user admin handler.
func NewAuthUsersHandler(users repository.UserRepository, sessions UserSessionsRevoker, audit AuditRecorder, tenantID string) *AuthUsersHandler {
	return &AuthUsersHandler{users: users, sessions: sessions, audit: audit, tenantID: tenantID}
}

type userResponse struct {
	ID             string  `json:"id"`
	TenantID       string  `json:"tenant_id"`
	Email          string  `json:"email"`
	DisplayName    string  `json:"display_name"`
	OIDCSubject    string  `json:"oidc_subject"`
	OIDCProviderID string  `json:"oidc_provider_id"`
	LastLoginAt    string  `json:"last_login_at"`
	CreatedAt      string  `json:"created_at"`
	DeactivatedAt  *string `json:"deactivated_at,omitempty"`
}

func userToResponse(u *userdomain.User) userResponse {
	r := userResponse{
		ID:             u.ID,
		TenantID:       u.TenantID,
		Email:          u.Email,
		DisplayName:    u.DisplayName,
		OIDCSubject:    u.OIDCSubject,
		OIDCProviderID: u.OIDCProviderID,
		LastLoginAt:    u.LastLoginAt.UTC().Format(time.RFC3339),
		CreatedAt:      u.CreatedAt.UTC().Format(time.RFC3339),
	}
	if u.DeactivatedAt != nil {
		s := u.DeactivatedAt.UTC().Format(time.RFC3339)
		r.DeactivatedAt = &s
	}
	return r
}

// List returns every user in the active tenant. Pagination + filter
// are accepted as query parameters; the repository's ListAll returns
// every row and we filter client-side for simplicity.
func (h *AuthUsersHandler) List(w http.ResponseWriter, r *http.Request) {
	caller, err := callerFromRequest(r)
	if err != nil {
		writeAuthError(w, err)
		return
	}
	users, lerr := h.users.ListAll(r.Context(), h.tenantID)
	if lerr != nil {
		Error(w, http.StatusInternalServerError, "could not list users")
		return
	}
	providerFilter := r.URL.Query().Get("oidc_provider_id")
	out := make([]userResponse, 0, len(users))
	for _, u := range users {
		if providerFilter != "" && u.OIDCProviderID != providerFilter {
			continue
		}
		out = append(out, userToResponse(u))
	}
	_ = h.audit.RecordEventWithCategory(r.Context(), caller.ActorID, caller.ActorType, "auth.user_list",
		domain.EventCategoryAuth, "user", "",
		map[string]interface{}{"count": len(out), "provider_filter": providerFilter})
	writeJSON(w, http.StatusOK, map[string]interface{}{"users": out})
}

// Deactivate sets deactivated_at on the user and cascade-revokes
// active sessions. Returns 204 on success.
func (h *AuthUsersHandler) Deactivate(w http.ResponseWriter, r *http.Request) {
	caller, err := callerFromRequest(r)
	if err != nil {
		writeAuthError(w, err)
		return
	}
	id := r.PathValue("id")
	if id == "" {
		Error(w, http.StatusBadRequest, "missing user id")
		return
	}
	u, gerr := h.users.Get(r.Context(), id)
	if gerr != nil {
		if errors.Is(gerr, repository.ErrUserNotFound) {
			Error(w, http.StatusNotFound, "user not found")
			return
		}
		Error(w, http.StatusInternalServerError, "could not load user")
		return
	}
	// Idempotent: deactivating an already-deactivated user is a no-op
	// from the wire's perspective.
	if u.DeactivatedAt != nil {
		w.WriteHeader(http.StatusNoContent)
		return
	}
	now := time.Now().UTC()
	u.DeactivatedAt = &now
	if uerr := h.users.Update(r.Context(), u); uerr != nil {
		Error(w, http.StatusInternalServerError, "could not deactivate user")
		return
	}
	// Cascade-revoke active sessions. Best-effort: revoke failures do
	// NOT roll back the deactivation (the user is already marked
	// deactivated; a leftover session expires at the absolute-TTL anyway).
	revokeStatus := "skipped_no_revoker"
	if h.sessions != nil {
		if rerr := h.sessions.RevokeAllForActor(r.Context(), u.ID, string(domain.ActorTypeUser)); rerr != nil {
			revokeStatus = "failed"
		} else {
			revokeStatus = "ok"
		}
	}
	_ = h.audit.RecordEventWithCategory(r.Context(), caller.ActorID, caller.ActorType, "auth.user_deactivated",
		domain.EventCategoryAuth, "user", u.ID,
		map[string]interface{}{
			"user_id":               u.ID,
			"oidc_provider_id":      u.OIDCProviderID,
			"session_revoke_status": revokeStatus,
		})
	w.WriteHeader(http.StatusNoContent)
}

// =============================================================================
// MED-12 — Auth runtime config read endpoint.
// =============================================================================

// AuthRuntimeConfigHandler exposes a flat-map view of the auth-related
// CERTCTL_* env vars so operators can verify the deployed
// configuration matches their intent from the GUI. Read-only — no
// mutation surface (config changes require a restart + env-var edit
// by design).
type AuthRuntimeConfigHandler struct {
	cfg   func() map[string]string
	audit AuditRecorder
}

// NewAuthRuntimeConfigHandler constructs the runtime-config handler.
// `cfg` is a closure so wires can be lazily evaluated against the
// running config without snapshot drift.
func NewAuthRuntimeConfigHandler(cfg func() map[string]string, audit AuditRecorder) *AuthRuntimeConfigHandler {
	return &AuthRuntimeConfigHandler{cfg: cfg, audit: audit}
}

func (h *AuthRuntimeConfigHandler) Get(w http.ResponseWriter, r *http.Request) {
	caller, err := callerFromRequest(r)
	if err != nil {
		writeAuthError(w, err)
		return
	}
	m := h.cfg()
	if m == nil {
		m = map[string]string{}
	}
	_ = h.audit.RecordEventWithCategory(r.Context(), caller.ActorID, caller.ActorType, "auth.runtime_config_read",
		domain.EventCategoryAuth, "config", "",
		map[string]interface{}{"key_count": len(m)})
	writeJSON(w, http.StatusOK, map[string]interface{}{"runtime_config": m})
}

// =============================================================================
// MED-7 — JWKS health endpoint.
// =============================================================================

// JWKSStatusProbe is the projection of *oidc.Service the JWKS-status
// handler uses to read the per-provider verifier counters. Production
// *oidc.Service satisfies this directly via the JWKSStatus method.
type JWKSStatusProbe interface {
	JWKSStatus(ctx context.Context, providerID string) (*oidcsvc.JWKSStatusSnapshot, error)
}

// AuthOIDCJWKSStatusHandler exposes per-provider JWKS health.
type AuthOIDCJWKSStatusHandler struct {
	probe JWKSStatusProbe
	audit AuditRecorder
}

// NewAuthOIDCJWKSStatusHandler constructs the JWKS-status handler.
func NewAuthOIDCJWKSStatusHandler(probe JWKSStatusProbe, audit AuditRecorder) *AuthOIDCJWKSStatusHandler {
	return &AuthOIDCJWKSStatusHandler{probe: probe, audit: audit}
}

func (h *AuthOIDCJWKSStatusHandler) Status(w http.ResponseWriter, r *http.Request) {
	caller, err := callerFromRequest(r)
	if err != nil {
		writeAuthError(w, err)
		return
	}
	id := r.PathValue("id")
	if id == "" {
		Error(w, http.StatusBadRequest, "missing provider id")
		return
	}
	snap, perr := h.probe.JWKSStatus(r.Context(), id)
	if perr != nil {
		if errors.Is(perr, repository.ErrOIDCProviderNotFound) {
			Error(w, http.StatusNotFound, "provider not found")
			return
		}
		Error(w, http.StatusInternalServerError, "could not read JWKS status")
		return
	}
	_ = h.audit.RecordEventWithCategory(r.Context(), caller.ActorID, caller.ActorType, "auth.oidc_jwks_status_read",
		domain.EventCategoryAuth, "oidc_provider", id,
		map[string]interface{}{"provider_id": id})
	writeJSON(w, http.StatusOK, snap)
}

// AuditRecorder is reused from auth_session_oidc.go — same package.