package http

import (
	"bytes"
	"context"
	"encoding/json"
	"io"
	stdhttp "net/http"
	"strings"
	"testing"
	"time"

	"github.com/coder/websocket"

	"gitea.dcglab.co.uk/steve/restic-manager/internal/api"
	"gitea.dcglab.co.uk/steve/restic-manager/internal/auth"
	"gitea.dcglab.co.uk/steve/restic-manager/internal/store"
)

// makePushHost is like makeHTTPHost but mints a known agent token so
// the test can dial /ws/agent as the host. Returns (hostID, raw token).
func makePushHost(t *testing.T, st *store.Store) (string, string) {
	t.Helper()
	const id = "01HSCHEDPUSH00000000000000"
	tok, _ := auth.NewToken()
	if err := st.CreateHost(context.Background(), store.Host{
		ID: id, Name: "ph", OS: "linux", Arch: "amd64",
		AgentVersion: "dev", ResticVersion: "0.16.0", ProtocolVersion: 1,
		EnrolledAt: time.Now().UTC(),
	}, auth.HashToken(tok), ""); err != nil {
		t.Fatalf("create host: %v", err)
	}
	return id, tok
}

// readUntilType pumps messages from the WS until one of the wanted
// types arrives or ctx times out. Returns the matched envelope.
// Useful because the on-hello path may push several messages
// (config.update first if creds exist, schedule.set, …).
func readUntilType(ctx context.Context, t *testing.T, c *websocket.Conn, want api.MessageType) api.Envelope {
	t.Helper()
	for {
		_, raw, err := c.Read(ctx)
		if err != nil {
			t.Fatalf("ws read waiting for %s: %v", want, err)
		}
		var env api.Envelope
		if err := json.Unmarshal(raw, &env); err != nil {
			t.Fatalf("envelope: %v (raw=%s)", err, raw)
		}
		t.Logf("recv: type=%s payload=%s", env.Type, env.Payload)
		if env.Type == want {
			return env
		}
	}
}

func TestSchedulePushOnHelloAndAckRoundtrip(t *testing.T) {
	t.Parallel()
	srv, url, st := newTestServerWithHub(t)
	_ = srv
	cookie := loginAndCookie(t, url)
	hostID, agentToken := makePushHost(t, st)

	// Pre-populate one schedule so we have something to push.
	body, _ := json.Marshal(scheduleAPI{
		Kind:     "backup",
		CronExpr: "@hourly",
		Paths:    []string{"/etc"},
		Enabled:  true,
	})
	req, _ := stdhttp.NewRequest("POST", url+"/api/hosts/"+hostID+"/schedules",
		bytes.NewReader(body))
	req.AddCookie(cookie)
	req.Header.Set("Content-Type", "application/json")
	res, err := stdhttp.DefaultClient.Do(req)
	if err != nil {
		t.Fatalf("create schedule: %v", err)
	}
	got, _ := io.ReadAll(res.Body)
	res.Body.Close()
	if res.StatusCode != stdhttp.StatusCreated {
		t.Fatalf("create schedule: %d %s", res.StatusCode, got)
	}
	var created scheduleAPI
	_ = json.Unmarshal(got, &created)

	// Dial the WS as the agent and send hello.
	wsURL := "ws" + strings.TrimPrefix(url, "http") + "/ws/agent"
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()
	c, _, err := websocket.Dial(ctx, wsURL, &websocket.DialOptions{
		HTTPHeader: stdhttp.Header{"Authorization": []string{"Bearer " + agentToken}},
	})
	if err != nil {
		t.Fatalf("dial: %v", err)
	}
	defer c.CloseNow()

	helloEnv, _ := api.Marshal(api.MsgHello, "", api.HelloPayload{
		ProtocolVersion: api.CurrentProtocolVersion,
		AgentVersion:    "test", ResticVersion: "test",
		Hostname: "ph", OS: api.OSLinux, Arch: api.ArchAmd64,
	})
	raw, _ := json.Marshal(helloEnv)
	if err := c.Write(ctx, websocket.MessageText, raw); err != nil {
		t.Fatalf("write hello: %v", err)
	}

	// Server should push schedule.set (our host has no creds, so the
	// config.update branch is silently skipped).
	pushedEnv := readUntilType(ctx, t, c, api.MsgScheduleSet)
	var pushed api.ScheduleSetPayload
	if err := pushedEnv.UnmarshalPayload(&pushed); err != nil {
		t.Fatalf("decode payload: %v", err)
	}
	if pushed.Version != 1 {
		t.Fatalf("pushed version: got %d, want 1", pushed.Version)
	}
	if len(pushed.Schedules) != 1 || pushed.Schedules[0].ID != created.ID {
		t.Fatalf("pushed schedules: %+v", pushed.Schedules)
	}
	if pushed.Schedules[0].CronExpr != "@hourly" || len(pushed.Schedules[0].Paths) != 1 {
		t.Fatalf("schedule contents: %+v", pushed.Schedules[0])
	}

	// Ack the version. Server should record it on the host row.
	ackEnv, _ := api.Marshal(api.MsgScheduleAck, "", api.ScheduleAckPayload{
		Version:   pushed.Version,
		AppliedAt: time.Now().UTC(),
	})
	raw, _ = json.Marshal(ackEnv)
	if err := c.Write(ctx, websocket.MessageText, raw); err != nil {
		t.Fatalf("write ack: %v", err)
	}

	// Wait for applied_schedule_version to flip.
	deadline := time.Now().Add(2 * time.Second)
	for time.Now().Before(deadline) {
		h, err := st.GetHost(context.Background(), hostID)
		if err == nil && h.AppliedScheduleVersion == pushed.Version {
			return
		}
		time.Sleep(20 * time.Millisecond)
	}
	h, _ := st.GetHost(context.Background(), hostID)
	t.Fatalf("applied_schedule_version did not advance: got %d, want %d",
		h.AppliedScheduleVersion, pushed.Version)
}

func TestSchedulePushOnCRUD(t *testing.T) {
	t.Parallel()
	srv, url, st := newTestServerWithHub(t)
	_ = srv
	cookie := loginAndCookie(t, url)
	hostID, agentToken := makePushHost(t, st)

	// Connect first so the CRUD push has somewhere to land.
	wsURL := "ws" + strings.TrimPrefix(url, "http") + "/ws/agent"
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()
	c, _, err := websocket.Dial(ctx, wsURL, &websocket.DialOptions{
		HTTPHeader: stdhttp.Header{"Authorization": []string{"Bearer " + agentToken}},
	})
	if err != nil {
		t.Fatalf("dial: %v", err)
	}
	defer c.CloseNow()

	helloEnv, _ := api.Marshal(api.MsgHello, "", api.HelloPayload{
		ProtocolVersion: api.CurrentProtocolVersion,
		AgentVersion:    "test", ResticVersion: "test",
		Hostname: "ph", OS: api.OSLinux, Arch: api.ArchAmd64,
	})
	raw, _ := json.Marshal(helloEnv)
	_ = c.Write(ctx, websocket.MessageText, raw)

	// Drain the on-hello schedule.set (will be version 0, empty list).
	first := readUntilType(ctx, t, c, api.MsgScheduleSet)
	var initial api.ScheduleSetPayload
	_ = first.UnmarshalPayload(&initial)
	if initial.Version != 0 || len(initial.Schedules) != 0 {
		t.Fatalf("initial push: %+v", initial)
	}

	// Now create a schedule via REST. The handler should fire a
	// schedule.set push asynchronously.
	body, _ := json.Marshal(scheduleAPI{
		Kind: "backup", CronExpr: "*/30 * * * *",
		Paths: []string{"/var/lib"}, Enabled: true,
	})
	req, _ := stdhttp.NewRequest("POST",
		url+"/api/hosts/"+hostID+"/schedules", bytes.NewReader(body))
	req.AddCookie(cookie)
	req.Header.Set("Content-Type", "application/json")
	res, err := stdhttp.DefaultClient.Do(req)
	if err != nil {
		t.Fatalf("create: %v", err)
	}
	res.Body.Close()
	if res.StatusCode != stdhttp.StatusCreated {
		t.Fatalf("create: %d", res.StatusCode)
	}

	// Wait for the pushed schedule.set with version 1.
	pushed := readUntilType(ctx, t, c, api.MsgScheduleSet)
	var pl api.ScheduleSetPayload
	_ = pushed.UnmarshalPayload(&pl)
	if pl.Version != 1 || len(pl.Schedules) != 1 {
		t.Fatalf("push after create: %+v", pl)
	}
}