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"`
}

// Memberships implements Adapter against GET /admin/realms/{realm}/users/{id}.
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)
	}
	return claimsFromAttributes(u.Attributes), nil
}

// claimsFromAttributes builds the membership list from a user's attribute
// projection. A user with no tenant_id and no tenant_slug attribute simply
// has no memberships — that is a valid state, not an error.
func claimsFromAttributes(attrs map[string][]string) []Claims {
	c := Claims{
		TenantID:     attrValue(attrs, "tenant_id"),
		TenantSlug:   attrValue(attrs, "tenant_slug"),
		OrgRoles:     attrValues(attrs, "org_roles"),
		Products:     attrValues(attrs, "products"),
		Plan:         attrValue(attrs, "plan"),
		TenantStatus: attrValue(attrs, "tenant_status"),
	}
	if c.TenantID == "" && c.TenantSlug == "" {
		return []Claims{}
	}
	return []Claims{c}
}

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
}