package httpapi

import (
	"bytes"
	"context"
	"crypto/sha256"
	"encoding/hex"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"net/url"
	"os"
	"testing"
	"time"

	"github.com/jackc/pgx/v5/pgxpool"

	"knowledge-governance/internal/governance"
	postgresstore "knowledge-governance/internal/platform/postgres"
)

// isolatedUISettingsURL 给本用例一个独立 schema。
//
// 这个用例会「创建候选并激活」——激活会把当前的 active 设置挤成 retired。若直接跑在
// 共享库（尤其是线上治理库）上，它会静默改掉真实的刷新策略与端点：2026-10-10 实测踩到，
// 真实那条 uis-d40ea1fc… 被 retired、测试负载（30/60/3600/14400 + 示例端点）被激活，
// 已用备份恢复。参照 internal/monitoring 的做法加 schema 隔离，杜绝再次发生。
func isolatedUISettingsURL(t *testing.T) string {
	t.Helper()
	databaseURL := os.Getenv("TEST_DATABASE_URL")
	if databaseURL == "" {
		t.Skip("TEST_DATABASE_URL is not set")
	}
	parsed, err := url.Parse(databaseURL)
	if err != nil {
		t.Fatal(err)
	}
	digest := sha256.Sum256([]byte(t.Name()))
	schema := "kgtest_" + hex.EncodeToString(digest[:8])
	ctx := context.Background()
	admin, err := pgxpool.New(ctx, databaseURL)
	if err != nil {
		t.Fatal(err)
	}
	defer admin.Close()
	if _, err := admin.Exec(ctx, "CREATE SCHEMA IF NOT EXISTS "+schema); err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() {
		cleanup, err := pgxpool.New(context.Background(), databaseURL)
		if err == nil {
			_, _ = cleanup.Exec(context.Background(), "DROP SCHEMA IF EXISTS "+schema+" CASCADE")
			cleanup.Close()
		}
	})
	query := parsed.Query()
	query.Set("search_path", schema)
	parsed.RawQuery = query.Encode()
	return parsed.String()
}

func TestUISettingsWriteReadBackIntegration(t *testing.T) {
	ctx := context.Background()
	pool, err := pgxpool.New(ctx, isolatedUISettingsURL(t))
	if err != nil {
		t.Fatal(err)
	}
	defer pool.Close()
	if err := postgresstore.ApplyMigrations(ctx, pool); err != nil {
		t.Fatal(err)
	}
	now := time.Date(2026, 9, 10, 9, 0, 0, 0, time.UTC)
	handler, err := NewHandler(Config{Store: postgresstore.NewStore(pool), Now: func() time.Time { return now }})
	if err != nil {
		t.Fatal(err)
	}

	create := httptest.NewRecorder()
	createRequest := httptest.NewRequest(http.MethodPost, "/api/v1/ui-settings/candidates", bytes.NewBufferString(`{"document_refresh_seconds":30,"resource_refresh_seconds":60,"stalled_after_seconds":3600,"finalizing_after_seconds":14400,"ingestion_concurrency":2,"test_weknora_base_url":"https://weknora.test.example:8443/weknora","production_weknora_base_url":"https://weknora.prod.example:8443/weknora","production_tenant_id":"10000","production_knowledge_base_id":"kb-prod-1"}`))
	createRequest.Header.Set("X-Governance-Action", "ui-settings")
	createRequest.Header.Set("Idempotency-Key", "op-e2e-uis-create")
	handler.ServeHTTP(create, createRequest)
	if create.Code != http.StatusCreated {
		t.Fatalf("create status=%d body=%s", create.Code, create.Body.String())
	}
	var candidate struct {
		Data governance.UISettings `json:"data"`
	}
	if err := json.NewDecoder(create.Body).Decode(&candidate); err != nil || candidate.Data.State != "validated" {
		t.Fatalf("candidate=%#v error=%v", candidate, err)
	}
	if candidate.Data.ProductionWeKnoraBaseURL != "https://weknora.prod.example:8443/weknora" || candidate.Data.TestWeKnoraBaseURL != "https://weknora.test.example:8443/weknora" || candidate.Data.ProductionTenantID != "10000" || candidate.Data.ProductionKnowledgeBaseID != "kb-prod-1" {
		t.Fatalf("service fields lost in the web write path: %#v", candidate.Data)
	}

	activate := httptest.NewRecorder()
	activateRequest := httptest.NewRequest(http.MethodPost, "/api/v1/ui-settings/"+candidate.Data.ID+"/activate", bytes.NewBufferString(`{}`))
	activateRequest.Header.Set("X-Governance-Action", "ui-settings")
	activateRequest.Header.Set("Idempotency-Key", "op-e2e-uis-activate")
	handler.ServeHTTP(activate, activateRequest)
	if activate.Code != http.StatusOK {
		t.Fatalf("activate status=%d body=%s", activate.Code, activate.Body.String())
	}

	get := httptest.NewRecorder()
	handler.ServeHTTP(get, httptest.NewRequest(http.MethodGet, "/api/v1/ui-settings", nil))
	if get.Code != http.StatusOK {
		t.Fatalf("get status=%d body=%s", get.Code, get.Body.String())
	}
	var active struct {
		Data governance.UISettings `json:"data"`
	}
	if err := json.NewDecoder(get.Body).Decode(&active); err != nil || active.Data.ID != candidate.Data.ID || active.Data.State != "active" || active.Data.DocumentRefreshSeconds != 30 {
		t.Fatalf("active=%#v error=%v", active, err)
	}
	if active.Data.ProductionWeKnoraBaseURL != "https://weknora.prod.example:8443/weknora" || active.Data.TestWeKnoraBaseURL != "https://weknora.test.example:8443/weknora" || active.Data.ProductionTenantID != "10000" || active.Data.ProductionKnowledgeBaseID != "kb-prod-1" {
		t.Fatalf("active service fields not served back to the console: %#v", active.Data)
	}
	var persistedEndpoint, persistedTestEndpoint, persistedTenant, persistedKnowledgeBase string
	if err := pool.QueryRow(ctx, `SELECT production_weknora_base_url,test_weknora_base_url,production_tenant_id,production_knowledge_base_id FROM ui_setting_revisions WHERE state='active'`).Scan(&persistedEndpoint, &persistedTestEndpoint, &persistedTenant, &persistedKnowledgeBase); err != nil || persistedEndpoint != "https://weknora.prod.example:8443/weknora" || persistedTestEndpoint != "https://weknora.test.example:8443/weknora" || persistedTenant != "10000" || persistedKnowledgeBase != "kb-prod-1" {
		t.Fatalf("persisted service fields=%q/%q/%q/%q error=%v", persistedEndpoint, persistedTestEndpoint, persistedTenant, persistedKnowledgeBase, err)
	}
	var activeCount, retiredCount int
	if err := pool.QueryRow(ctx, `SELECT COUNT(*) FILTER(WHERE state='active'),COUNT(*) FILTER(WHERE state='retired') FROM ui_setting_revisions`).Scan(&activeCount, &retiredCount); err != nil || activeCount != 1 || retiredCount != 1 {
		t.Fatalf("active=%d retired=%d error=%v", activeCount, retiredCount, err)
	}
}