package httpapi

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"time"

	"knowledge-governance/internal/libraryexecutor"
)

// fakeJobStore 只是"存储"替身；执行器状态同样是它的一条记录。
func (s *fakeJobStore) LibraryExecutorStatus(_ context.Context, instance string) (*libraryexecutor.Observation, error) {
	if s.executorStatus == nil || s.executorStatus.Instance != instance {
		return nil, nil
	}
	return s.executorStatus, nil
}

// healthyExecutor 返回一份"worker 刚观测到、指向本实例"的记录。
func healthyExecutor(now time.Time) *libraryexecutor.Observation {
	return &libraryexecutor.Observation{
		Instance: "kgmaint-weknora", Reachable: true, ObservedAt: now,
		Identity: libraryexecutor.Identity{Project: "kgmaint-weknora", SourceApp: "kgmaint-app",
			ArchiveRoot: "/tmp/kg-e2e/archive", Writers: "app"},
	}
}

// captureReadyConfig 是"执行器真的可用"时的配置：实例、期望项目与观测三者一致。
func captureReadyConfig(store *fakeJobStore) Config {
	store.executorStatus = healthyExecutor(time.Now().UTC())
	return Config{
		Store:                 store,
		LibraryAgentSocket:    "/run/library-agent/agent.sock",
		LibrarySourceInstance: "kgmaint-weknora",
		LibrarySourceProject:  "kgmaint-weknora",
		LibraryArchiveRoot:    "/var/lib/knowledge-governance/library",
	}
}

func decodeCaptureRefusal(t *testing.T, recorder *httptest.ResponseRecorder) (string, string) {
	t.Helper()
	var body struct {
		Code   string `json:"code"`
		Reason string `json:"reason"`
	}
	if err := json.Unmarshal(recorder.Body.Bytes(), &body); err != nil {
		t.Fatalf("body %s: %v", recorder.Body.String(), err)
	}
	return body.Code, body.Reason
}

// 页面上的"可发起"必须等于接口真的会接受：配置了 socket 但执行器不可达、
// 指向别的实例、降级或过期时，都必须带着原因拒绝，而不是先排队再失败。
func TestLibraryCaptureRefusesWhenExecutorIsNotVerified(t *testing.T) {
	now := time.Now().UTC()
	tests := []struct {
		name   string
		config func(*Config)
		text   string
	}{
		{name: "no instance identity", config: func(c *Config) {
			c.LibrarySourceInstance = ""
		}, text: "LIBRARY_SOURCE_INSTANCE"},
		{name: "nothing reported yet", config: func(c *Config) {
			c.Store.(*fakeJobStore).executorStatus = nil
		}, text: "还没有上报状态"},
		{name: "unreachable", config: func(c *Config) {
			c.Store.(*fakeJobStore).executorStatus.Reachable = false
			c.Store.(*fakeJobStore).executorStatus.Error = "library agent is unreachable"
		}, text: "不可达"},
		{name: "stale observation", config: func(c *Config) {
			c.Store.(*fakeJobStore).executorStatus.ObservedAt = now.Add(-10 * time.Minute)
		}, text: "已过期"},
		{name: "points at another instance", config: func(c *Config) {
			c.Store.(*fakeJobStore).executorStatus.Identity.Project = "weknora071full"
		}, text: "指向的实例不匹配"},
		{name: "degraded", config: func(c *Config) {
			c.Store.(*fakeJobStore).executorStatus.Degraded = "写入者恢复失败"
		}, text: "降级"},
	}
	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			store := &fakeJobStore{}
			config := captureReadyConfig(store)
			test.config(&config)
			recorder := httptest.NewRecorder()
			libraryCaptureEnqueue(recorder, captureRequest(`{"scope":"internal"}`), config)
			if recorder.Code != http.StatusServiceUnavailable {
				t.Fatalf("status=%d body=%s", recorder.Code, recorder.Body.String())
			}
			code, reason := decodeCaptureRefusal(t, recorder)
			if code != "library_capture_unavailable" {
				t.Fatalf("code=%q body=%s", code, recorder.Body.String())
			}
			if reason == "" || !strings.Contains(reason, test.text) {
				t.Fatalf("reason=%q want it to mention %q", reason, test.text)
			}
			if store.enqueued.Type != "" {
				t.Fatal("refused capture still enqueued a job")
			}
		})
	}
}

// The overview must report the same reason the capture endpoint would use.
func TestLibraryOverviewReportsExecutorIdentityAndReason(t *testing.T) {
	store := &fakeLibraryStore{}
	config := captureReadyConfig(&store.fakeJobStore)
	// libraryJobStore 的方法在 fakeLibraryStore 上，执行器状态在嵌入的 fakeJobStore 上。
	config.Store = store
	recorder := httptest.NewRecorder()
	libraryOverviewHandler(recorder, httptest.NewRequest(http.MethodGet, "/api/v1/library/overview?scope=internal", nil), config)
	if recorder.Code != http.StatusOK {
		t.Fatalf("status=%d body=%s", recorder.Code, recorder.Body.String())
	}
	var body struct {
		CaptureAvailable bool `json:"capture_available"`
		Executor         struct {
			Available   bool   `json:"available"`
			Instance    string `json:"instance"`
			Project     string `json:"project"`
			SourceApp   string `json:"source_app"`
			ArchiveRoot string `json:"archive_root"`
		} `json:"executor"`
	}
	if err := json.Unmarshal(recorder.Body.Bytes(), &body); err != nil {
		t.Fatal(err)
	}
	if !body.CaptureAvailable || !body.Executor.Available {
		t.Fatalf("overview did not report an available executor: %s", recorder.Body.String())
	}
	if body.Executor.Project != "kgmaint-weknora" || body.Executor.SourceApp != "kgmaint-app" ||
		body.Executor.ArchiveRoot != "/tmp/kg-e2e/archive" || body.Executor.Instance != "kgmaint-weknora" {
		t.Fatalf("executor view = %+v", body.Executor)
	}

	store.fakeJobStore.executorStatus.Identity.Project = "weknora071full"
	recorder = httptest.NewRecorder()
	libraryOverviewHandler(recorder, httptest.NewRequest(http.MethodGet, "/api/v1/library/overview?scope=internal", nil), config)
	if err := json.Unmarshal(recorder.Body.Bytes(), &body); err != nil {
		t.Fatal(err)
	}
	if body.CaptureAvailable {
		t.Fatalf("overview still says available after the executor moved to another instance: %s", recorder.Body.String())
	}
}

// "恢复至该版本"必须由真实条件决定：没有 restore 授权就明确说出来。
func TestLibraryRestoreAvailabilityExplainsMissingAuthorization(t *testing.T) {
	store := &fakeJobStore{}
	config := Config{Store: store, ProductionReleaseRequestsEnabled: true, ProductionBackupRestoreVerified: true}
	recorder := httptest.NewRecorder()
	libraryRestoreAvailability(recorder, httptest.NewRequest(http.MethodGet,
		"/api/v1/library/restore-availability?scope=internal&snapshot_id=snap-1", nil), config)
	if recorder.Code != http.StatusOK {
		t.Fatalf("status=%d body=%s", recorder.Code, recorder.Body.String())
	}
	var body struct {
		Allowed       bool     `json:"allowed"`
		Reasons       []string `json:"reasons"`
		Authorization struct {
			State string `json:"state"`
		} `json:"authorization"`
	}
	if err := json.Unmarshal(recorder.Body.Bytes(), &body); err != nil {
		t.Fatal(err)
	}
	if body.Allowed || body.Authorization.State != "none" || len(body.Reasons) == 0 {
		t.Fatalf("body=%s", recorder.Body.String())
	}
	found := false
	for _, reason := range body.Reasons {
		if strings.Contains(reason, "恢复授权") {
			found = true
		}
	}
	if !found {
		t.Fatalf("reasons = %v", body.Reasons)
	}
}