package keycloak

import (
	"context"
	"fmt"
	"net/http"
	"strings"
)

// userRepresentation is the slice of the Admin API's UserRepresentation we
// need. Attributes arrive as map[name][]values; the KC admin console writes
// multivalued attributes either as separate list entries or as one entry
// joined with "##", so both shapes must be accepted.
type userRepresentation struct {
	ID         string              `json:"id"`
	Username   string              `json:"username"`
	Enabled    bool                `json:"enabled"`
	Attributes map[string][]string `json:"attributes"`
}

// memberOrgRepresentation is the slice of OrganizationRepresentation the
// membership query needs: the alias IS the tenant slug and the org
// attribute "tenant_id" carries the registry tenant UUID (both written by
// CreateOrgAndInvite, or provisioned by the realm admin for pre-existing
// tenants).
type memberOrgRepresentation struct {
	ID         string              `json:"id"`
	Alias      string              `json:"alias"`
	Enabled    bool                `json:"enabled"`
	Attributes map[string][]string `json:"attributes"`
}

// Memberships implements Adapter with Keycloak Organizations as the
// authoritative membership source (prod shape, realm orgs enabled
// 2026-09-01):
//
//  1. GET /users/{id} — preserves ErrUserNotFound semantics and supplies
//     the per-user claim attributes (org_roles / products / plan /
//     tenant_status) that SyncClaims maintains.
//  2. GET /organizations/members/{id}/organizations — the memberships.
//
// One Claims entry per ENABLED organization: TenantID = org attribute
// "tenant_id" (registry UUID), TenantSlug = org alias. A disabled org
// grants no membership. A user in no organization has zero memberships —
// the legacy user-attribute tenant projection is NO LONGER consulted for
// membership, so a stale tenant_id/tenant_slug user attribute cannot
// grant access the org model has revoked.
func (a *HTTPAdapter) Memberships(ctx context.Context, userID string) ([]Claims, error) {
	var u userRepresentation
	resp, err := a.adminCall(ctx, http.MethodGet, "/users/"+userID, nil, &u)
	if err != nil {
		return nil, err
	}
	if resp.StatusCode == http.StatusNotFound {
		_ = resp.Body.Close()
		return nil, ErrUserNotFound
	}
	if resp.StatusCode/100 != 2 {
		_ = resp.Body.Close()
		return nil, fmt.Errorf("keycloak get user: %d", resp.StatusCode)
	}

	var orgs []memberOrgRepresentation
	resp, err = a.adminCall(
		ctx, http.MethodGet, "/organizations/members/"+userID+"/organizations", nil, &orgs,
	)
	if err != nil {
		return nil, err
	}
	if resp.StatusCode/100 != 2 {
		_ = resp.Body.Close()
		return nil, fmt.Errorf("keycloak member organizations: %d", resp.StatusCode)
	}

	claims := []Claims{}
	for _, org := range orgs {
		if !org.Enabled {
			continue
		}
		claims = append(claims, Claims{
			TenantID:     attrValue(org.Attributes, "tenant_id"),
			TenantSlug:   org.Alias,
			OrgRoles:     attrValues(u.Attributes, "org_roles"),
			Products:     attrValues(u.Attributes, "products"),
			Plan:         attrValue(u.Attributes, "plan"),
			TenantStatus: attrValue(u.Attributes, "tenant_status"),
		})
	}
	return claims, nil
}

func attrValue(attrs map[string][]string, key string) string {
	if vs := attrValues(attrs, key); len(vs) > 0 {
		return vs[0]
	}
	return ""
}

func attrValues(attrs map[string][]string, key string) []string {
	out := []string{}
	for _, entry := range attrs[key] {
		for _, v := range strings.Split(entry, "##") {
			if v = strings.TrimSpace(v); v != "" {
				out = append(out, v)
			}
		}
	}
	return out
}