package httpapi

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"safesight-agent/internal/config"
	"safesight-agent/internal/mediaserver"
)

func TestHandleConfigCandidateApplyPromotesCandidateAndBacksUpCurrent(t *testing.T) {
	reloadCalls := 0
	msServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method == http.MethodPost && r.URL.Path == "/api/config/reload" {
			reloadCalls++
			w.WriteHeader(http.StatusOK)
			_, _ = w.Write([]byte(`{"ok":true}`))
			return
		}
		t.Fatalf("unexpected media-server request %s %s", r.Method, r.URL.Path)
	}))
	defer msServer.Close()

	ms, err := mediaserver.New(msServer.URL, 3000, 1, nil)
	if err != nil {
		t.Fatalf("new mediaserver client: %v", err)
	}

	dir := t.TempDir()
	cfgPath := filepath.Join(dir, "media-server.json")
	currentBody := []byte(`{"templates":{"tpl":{"nodes":[],"edges":[]}},"instances":[],"metadata":{"config_id":"current","config_version":"v1"}}`)
	candidateBody := []byte(`{"templates":{"tpl":{"nodes":[],"edges":[]}},"instances":[],"metadata":{"config_id":"candidate","config_version":"v2"}}`)
	if err := os.WriteFile(cfgPath, currentBody, 0o644); err != nil {
		t.Fatalf("write current: %v", err)
	}
	if err := os.WriteFile(cfgPath+".candidate.json", candidateBody, 0o644); err != nil {
		t.Fatalf("write candidate: %v", err)
	}

	s := &Server{
		agentCfg: config.AgentConfig{ConfigPath: cfgPath, Token: "test-token"},
		ms:       ms,
	}
	req := httptest.NewRequest(http.MethodPost, "/v1/config/candidate/apply", strings.NewReader(`{}`))
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("X-RK-Token", "test-token")
	rr := httptest.NewRecorder()

	s.handleConfigCandidateApply(rr, req)

	if rr.Code != http.StatusOK {
		t.Fatalf("status code: got %d body=%s", rr.Code, rr.Body.String())
	}
	if reloadCalls != 1 {
		t.Fatalf("reload calls = %d", reloadCalls)
	}

	gotCurrent, err := os.ReadFile(cfgPath)
	if err != nil {
		t.Fatalf("read current: %v", err)
	}
	if strings.TrimSpace(string(gotCurrent)) != string(candidateBody) {
		t.Fatalf("current body = %s", gotCurrent)
	}
	gotLastGood, err := os.ReadFile(cfgPath + ".last_good.json")
	if err != nil {
		t.Fatalf("read last_good: %v", err)
	}
	if strings.TrimSpace(string(gotLastGood)) != string(currentBody) {
		t.Fatalf("last_good body = %s", gotLastGood)
	}
	if _, err := os.Stat(cfgPath + ".candidate.json"); !os.IsNotExist(err) {
		t.Fatalf("candidate should be removed, stat err=%v", err)
	}

	var resp map[string]any
	if err := json.Unmarshal(rr.Body.Bytes(), &resp); err != nil {
		t.Fatalf("decode response: %v", err)
	}
	if resp["ok"] != true {
		t.Fatalf("response = %#v", resp)
	}
	status, ok := resp["status"].(map[string]any)
	if !ok {
		t.Fatalf("status missing: %#v", resp)
	}
	metadata, ok := status["metadata"].(map[string]any)
	if !ok || metadata["config_id"] != "candidate" {
		t.Fatalf("status metadata = %#v", status["metadata"])
	}
	candidate, ok := status["candidate"].(map[string]any)
	if !ok || candidate["exists"] != false {
		t.Fatalf("status candidate = %#v", status["candidate"])
	}
}

func TestApplyCandidateConfigBytes(t *testing.T) {
	reloadCalls := 0
	msServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method == http.MethodPost && r.URL.Path == "/api/config/reload" {
			reloadCalls++
			w.WriteHeader(http.StatusOK)
			return
		}
		t.Fatalf("unexpected media-server request %s %s", r.Method, r.URL.Path)
	}))
	defer msServer.Close()
	ms, err := mediaserver.New(msServer.URL, 3000, 1, nil)
	if err != nil {
		t.Fatalf("new mediaserver client: %v", err)
	}

	dir := t.TempDir()
	cfgPath := filepath.Join(dir, "media-server.json")
	currentBody := []byte(`{"templates":{"tpl":{"nodes":[],"edges":[]}},"instances":[],"metadata":{"config_id":"current","config_version":"v1"}}`)
	candidateBody := []byte(`{"templates":{"tpl":{"nodes":[],"edges":[]}},"instances":[],"metadata":{"config_id":"candidate","config_version":"v2"}}`)
	if err := os.WriteFile(cfgPath, currentBody, 0o644); err != nil {
		t.Fatalf("write current: %v", err)
	}

	s := &Server{
		agentCfg: config.AgentConfig{ConfigPath: cfgPath},
		ms:       ms,
	}
	if err := s.applyCandidateConfigBytes(context.Background(), candidateBody); err != nil {
		t.Fatalf("applyCandidateConfigBytes: %v", err)
	}
	if reloadCalls != 1 {
		t.Fatalf("reload calls = %d", reloadCalls)
	}
	gotLastGood, err := os.ReadFile(cfgPath + ".last_good.json")
	if err != nil {
		t.Fatalf("read last_good: %v", err)
	}
	if strings.TrimSpace(string(gotLastGood)) != string(currentBody) {
		t.Fatalf("last_good body = %s", gotLastGood)
	}
}

func TestHandleMediaRollbackRestoresPreviousConfig(t *testing.T) {
	reloadCalls := 0
	msServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method == http.MethodPost && r.URL.Path == "/api/config/reload" {
			reloadCalls++
			w.WriteHeader(http.StatusOK)
			_, _ = w.Write([]byte(`{"ok":true}`))
			return
		}
		t.Fatalf("unexpected media-server request %s %s", r.Method, r.URL.Path)
	}))
	defer msServer.Close()

	ms, err := mediaserver.New(msServer.URL, 3000, 1, nil)
	if err != nil {
		t.Fatalf("new mediaserver client: %v", err)
	}

	dir := t.TempDir()
	cfgPath := filepath.Join(dir, "media-server.json")
	currentBody := []byte(`{"templates":{"tpl":{"nodes":[],"edges":[]}},"instances":[],"metadata":{"config_id":"current","config_version":"v2"}}`)
	previousBody := []byte(`{"templates":{"tpl":{"nodes":[],"edges":[]}},"instances":[],"metadata":{"config_id":"previous","config_version":"v1"}}`)
	if err := os.WriteFile(cfgPath, currentBody, 0o644); err != nil {
		t.Fatalf("write current: %v", err)
	}
	if err := os.WriteFile(cfgPath+".last_good.json", previousBody, 0o644); err != nil {
		t.Fatalf("write previous: %v", err)
	}

	s := &Server{
		agentCfg: config.AgentConfig{ConfigPath: cfgPath, Token: "test-token"},
		ms:       ms,
	}
	req := httptest.NewRequest(http.MethodPost, "/v1/media-server/rollback", nil)
	req.Header.Set("X-RK-Token", "test-token")
	rr := httptest.NewRecorder()

	s.handleMediaRollback(rr, req)

	if rr.Code != http.StatusOK {
		t.Fatalf("status code: got %d body=%s", rr.Code, rr.Body.String())
	}
	if reloadCalls != 1 {
		t.Fatalf("reload calls = %d", reloadCalls)
	}
	gotCurrent, err := os.ReadFile(cfgPath)
	if err != nil {
		t.Fatalf("read current: %v", err)
	}
	if strings.TrimSpace(string(gotCurrent)) != string(previousBody) {
		t.Fatalf("current body = %s", gotCurrent)
	}
}

func TestApplyRootConfigBytesRestoresPreviousWhenReloadFails(t *testing.T) {
	reloadCalls := 0
	msServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method == http.MethodPost && r.URL.Path == "/api/config/reload" {
			reloadCalls++
			if reloadCalls == 1 {
				w.WriteHeader(http.StatusInternalServerError)
				_, _ = w.Write([]byte(`{"error":"reload failed"}`))
				return
			}
			w.WriteHeader(http.StatusOK)
			_, _ = w.Write([]byte(`{"ok":true}`))
			return
		}
		t.Fatalf("unexpected media-server request %s %s", r.Method, r.URL.Path)
	}))
	defer msServer.Close()

	ms, err := mediaserver.New(msServer.URL, 3000, 1, nil)
	if err != nil {
		t.Fatalf("new mediaserver client: %v", err)
	}

	dir := t.TempDir()
	cfgPath := filepath.Join(dir, "media-server.json")
	currentBody := []byte(`{"templates":{"tpl":{"nodes":[],"edges":[]}},"instances":[],"metadata":{"config_id":"current","config_version":"v1"}}`)
	newBody := []byte(`{"templates":{"tpl":{"nodes":[],"edges":[]}},"instances":[],"metadata":{"config_id":"new","config_version":"v2"}}`)
	if err := os.WriteFile(cfgPath, currentBody, 0o644); err != nil {
		t.Fatalf("write current: %v", err)
	}

	s := &Server{
		agentCfg: config.AgentConfig{ConfigPath: cfgPath},
		ms:       ms,
	}
	err = s.applyRootConfigBytes(context.Background(), newBody)
	if err == nil || !strings.Contains(err.Error(), "restored previous config") {
		t.Fatalf("applyRootConfigBytes err = %v", err)
	}
	if reloadCalls != 2 {
		t.Fatalf("reload calls = %d", reloadCalls)
	}
	gotCurrent, err := os.ReadFile(cfgPath)
	if err != nil {
		t.Fatalf("read current: %v", err)
	}
	if strings.TrimSpace(string(gotCurrent)) != string(currentBody) {
		t.Fatalf("current body = %s", gotCurrent)
	}
}