package server

import (
	"context"
	"encoding/json"
	"net"
	"net/http"
	"path/filepath"
	"sync/atomic"
	"testing"
	"time"

	"music-server/internal/backend"
	"music-server/internal/config"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

// blockSync replaces the sync service with one that keeps running until the returned function is called.
func (e *testEnv) blockSync() (release func()) {
	ch := make(chan struct{})
	e.server.sync = backend.NewSyncService(e.store, e.cfg.MusicPath, func(context.Context) { <-ch })
	e.handler = e.server.RegisterRoutes()
	return func() { close(ch); e.server.sync.Wait() }
}

func TestDestructiveSyncEndpointsIgnoreGet(t *testing.T) {
	e := newTestEnv(t)
	e.addSong("Game A", "Song", "a")
	for _, path := range []string{"/api/v1/sync", "/api/v1/sync/full", "/api/v1/sync/reset"} {
		// GET falls through to the frontend's static files, which answer 404.
		assert.Equal(t, http.StatusNotFound, e.do(http.MethodGet, path).Code, path)
	}
	assert.False(t, e.server.sync.IsSyncing(), "no sync was started")
	assert.Len(t, e.store.Songs, 1, "nothing was deleted")
}

func TestSyncStartAndLock(t *testing.T) {
	e := newTestEnv(t)
	e.addSong("Game A", "Song", "a")
	release := e.blockSync()

	assert.Equal(t, http.StatusOK, e.do(http.MethodPost, "/api/v1/sync").Code)
	assert.Equal(t, http.StatusLocked, e.do(http.MethodPost, "/api/v1/sync/full").Code)
	assert.Equal(t, http.StatusLocked, e.do(http.MethodPost, "/api/v1/sync/reset").Code)
	assert.Equal(t, http.StatusLocked, e.do(http.MethodGet, "/api/v1/music/rand").Code)
	assert.Equal(t, http.StatusOK, e.do(http.MethodGet, "/api/v1/music/info").Code, "info is available during sync")

	progress := e.do(http.MethodGet, "/api/v1/sync/progress")
	assert.Equal(t, http.StatusOK, progress.Code)
	assert.Contains(t, progress.Body.String(), `"progress"`)

	release()
	assert.Equal(t, http.StatusOK, e.do(http.MethodGet, "/api/v1/music/all").Code)
	result := e.do(http.MethodGet, "/api/v1/sync/progress")
	assert.Contains(t, result.Body.String(), `"total_time"`)
}

func TestSyncResetEndpoint(t *testing.T) {
	e := newTestEnv(t)
	e.addSong("Game A", "Song", "a")
	assert.Equal(t, http.StatusOK, e.do(http.MethodPost, "/api/v1/sync/reset").Code)
	assert.Empty(t, e.store.Soundtracks)
	assert.Empty(t, e.store.Songs)
}

func TestLegacyRoutesAreRemoved(t *testing.T) {
	e := newTestEnv(t)
	for _, path := range []string{"/version", "/health", "/music/list", "/music/rand", "/characters", "/sync/progress"} {
		assert.Equal(t, http.StatusNotFound, e.do(http.MethodGet, path).Code, path)
	}
	assert.Equal(t, http.StatusMethodNotAllowed, e.do(http.MethodPost, "/sync").Code)
	assert.False(t, e.server.sync.IsSyncing())
}

func TestVersionEndpoints(t *testing.T) {
	e := newTestEnv(t)
	var latest backend.VersionData
	require.NoError(t, json.Unmarshal(e.do(http.MethodGet, "/api/v1/version").Body.Bytes(), &latest))
	assert.Equal(t, backend.GetLatestVersion(), latest)

	var history []backend.VersionData
	require.NoError(t, json.Unmarshal(e.do(http.MethodGet, "/api/v1/version/history").Body.Bytes(), &history))
	assert.Equal(t, backend.GetVersionHistory(), history)
}

func TestHealthEndpoint(t *testing.T) {
	e := newTestEnv(t)
	rec := e.do(http.MethodGet, "/api/v1/health")
	assert.Equal(t, http.StatusOK, rec.Code)
	assert.JSONEq(t, `{"status":"up"}`, rec.Body.String())
}

func TestSyncAliasesAreRemoved(t *testing.T) {
	e := newTestEnv(t)
	for _, path := range []string{"/api/v1/sync/new", "/api/v1/sync/quick", "/api/v1/sync/new/full"} {
		assert.NotEqual(t, http.StatusOK, e.do(http.MethodPost, path).Code, path)
	}
	assert.False(t, e.server.sync.IsSyncing())
}

func TestDocsAndSpecLinks(t *testing.T) {
	e := newTestEnv(t)
	assert.Equal(t, http.StatusOK, e.do(http.MethodGet, "/docs").Code)
	for _, path := range []string{"/openapi.json", "/openapi.yaml", "/openapi-3.0.json"} {
		assert.Equal(t, http.StatusOK, e.do(http.MethodGet, path).Code, path)
	}
	rec := e.do(http.MethodGet, "/openapi")
	assert.Equal(t, http.StatusMovedPermanently, rec.Code)
	assert.Equal(t, "/openapi.json", rec.Header().Get("Location"))
	assert.Equal(t, "/docs", e.do(http.MethodGet, "/swagger/index.html").Header().Get("Location"))
}

func TestSearchPageAndFrontend(t *testing.T) {
	e := newTestEnv(t)
	e.addSong("Kingdom Hearts", "Dearly Beloved", "x")

	assert.Equal(t, http.StatusOK, e.do(http.MethodGet, "/search").Code)
	rec := e.do(http.MethodPost, "/find")
	assert.Equal(t, http.StatusOK, rec.Code)
	assert.Contains(t, rec.Body.String(), "Kingdom Hearts")

	rec = e.do(http.MethodGet, "/")
	assert.Equal(t, http.StatusOK, rec.Code)
	assert.Contains(t, rec.Body.String(), "frontend")
}

func TestFrontendConfigHasAPIPassword(t *testing.T) {
	e := newTestEnv(t, func(c *config.Config) { c.APIPassword = `pa'ss"word` })
	writeFile(t, filepath.Join(e.cfg.FrontendPath, "config.js"), "stale")

	rec := e.do(http.MethodGet, "/config.js")
	assert.Equal(t, http.StatusOK, rec.Code)
	assert.Equal(t, "text/javascript; charset=utf-8", rec.Header().Get("Content-Type"))
	assert.Equal(t, "no-store", rec.Header().Get("Cache-Control"))
	assert.Equal(t, `window.__RUNTIME_CONFIG__ = {"API_HOSTNAME":"","API_PASSWORD":"pa'ss\"word"};`+"\n", rec.Body.String())
}

func TestShutdownWaitsForRequestsBeforeClosingDatabase(t *testing.T) {
	e := newTestEnv(t)
	started := make(chan struct{})
	release := make(chan struct{})
	var requestDone atomic.Bool
	e.server.httpServer.Handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		close(started)
		<-release
		requestDone.Store(true)
	})
	var closedAfterRequest atomic.Bool
	e.db.onClose = func() { closedAfterRequest.Store(requestDone.Load()) }

	ln, err := net.Listen("tcp", "127.0.0.1:0")
	require.NoError(t, err)
	go e.server.httpServer.Serve(ln)

	responded := make(chan error, 1)
	go func() {
		resp, err := http.Get("http://" + ln.Addr().String())
		if err == nil {
			resp.Body.Close()
		}
		responded <- err
	}()
	<-started

	shutdownDone := make(chan error, 1)
	go func() { shutdownDone <- e.server.Shutdown(context.Background()) }()

	time.Sleep(50 * time.Millisecond)
	assert.False(t, e.db.closed.Load(), "database must stay open while a request is running")

	close(release)
	require.NoError(t, <-responded)
	require.NoError(t, <-shutdownDone)
	assert.True(t, e.db.closed.Load())
	assert.True(t, closedAfterRequest.Load())
}

func TestTrustedProxies(t *testing.T) {
	// Without trusted proxies the forwarded header is ignored, so all requests share one bucket.
	e := newTestEnv(t)
	for i := range 10 {
		e.doBody(http.MethodPost, "/api/v1/token", `{}`, "X-Forwarded-For", "10.0.0."+string(rune('0'+i)))
	}
	assert.Equal(t, http.StatusTooManyRequests, e.doBody(http.MethodPost, "/api/v1/token", `{}`, "X-Forwarded-For", "10.0.1.1").Code)

	// httptest requests come from 192.0.2.1, which is trusted here.
	e = newTestEnv(t, func(c *config.Config) {
		_, trusted, _ := net.ParseCIDR("192.0.2.0/24")
		c.TrustedProxies = []*net.IPNet{trusted}
	})
	for range 10 {
		e.doBody(http.MethodPost, "/api/v1/token", `{}`, "X-Forwarded-For", "10.0.0.1")
	}
	assert.Equal(t, http.StatusTooManyRequests, e.doBody(http.MethodPost, "/api/v1/token", `{}`, "X-Forwarded-For", "10.0.0.1").Code)
	assert.Equal(t, http.StatusOK, e.doBody(http.MethodPost, "/api/v1/token", `{}`, "X-Forwarded-For", "10.0.0.2").Code)
}