package main

import (
	"encoding/json"
	"errors"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"testing"
	"time"
)

// Defends novox/hq ADR 0260: a value another module keeps reaches the bar over the bus, through this
// module's own bundle and directory; a dead watch is never silent; a removed block is no longer kept;
// and a value frozen at its source hides.

func TestAValueIsKeptAsItsTextDatedByItsAtAndGoneWhenDeleted(t *testing.T) {
	dir := t.TempDir()
	w := Wanted{"power.draw", "laptop"}
	at := time.Date(2026, 10, 8, 12, 0, 0, 0, time.UTC)
	if err := keep(dir, w, "put", json.RawMessage(`{"text":"18.2 W machine","at":"2026-10-08T12:00:00Z"}`)); err != nil {
		t.Fatal(err)
	}
	path := filepath.Join(dir, "power.draw@laptop")
	b, err := os.ReadFile(path)
	info, _ := os.Stat(path)
	if err != nil || string(b) != "18.2 W machine\n" || !info.ModTime().Equal(at) {
		t.Fatalf("%q %v, dated %v", b, err, info.ModTime())
	}
	if err := keep(dir, w, "delete", nil); err != nil {
		t.Fatal(err)
	}
	if _, err := os.Stat(path); !os.IsNotExist(err) {
		t.Fatal("a deleted value is still shown")
	}
	if err := keep(dir, w, "put", json.RawMessage(`"no text"`)); err == nil {
		t.Fatal("a value with no text was kept")
	}
}

type fakeBus struct {
	refuse  bool
	watched []Wanted
	handles map[Wanted]func(string, json.RawMessage) error
	gets    int
	value   json.RawMessage
}

func (b *fakeBus) bus() Bus {
	return Bus{
		Watch: func(state, key string, h func(string, json.RawMessage) error) error {
			if b.refuse {
				return errors.New("not granted")
			}
			w := Wanted{state, key}
			b.watched = append(b.watched, w)
			if b.handles == nil {
				b.handles = map[Wanted]func(string, json.RawMessage) error{}
			}
			b.handles[w] = h
			return nil
		},
		Get: func(string, string) (json.RawMessage, bool, error) { b.gets++; return b.value, b.value != nil, nil },
	}
}

func barFiles(t *testing.T, content string) []string {
	t.Helper()
	f := filepath.Join(t.TempDir(), "bottom-bar.toml")
	if err := os.WriteFile(f, []byte(content), 0o644); err != nil {
		t.Fatal(err)
	}
	return []string{f}
}

func TestAFollowerSaysARefusedWatchRereadsASilentOneAndDropsARemovedBlock(t *testing.T) {
	now := time.Date(2026, 10, 8, 12, 0, 0, 0, time.UTC)
	var said []string
	b := &fakeBus{refuse: true}
	dir := t.TempDir()
	f := &Follower{Dir: dir, Bus: b.bus(), Now: func() time.Time { return now }, Say: func(s string) { said = append(said, s) }}
	bar := barFiles(t, `command = "~/.local/bin/i3status-value power.draw laptop"`)

	// Refused: said, and tried again the next round.
	f.Round(bar)
	if len(said) != 1 || !strings.Contains(said[0], "cannot watch power.draw laptop: not granted") {
		t.Fatalf("%v", said)
	}
	b.refuse = false
	f.Round(bar)
	if len(b.watched) != 1 {
		t.Fatalf("watched %v", b.watched)
	}

	// Silent for longer than Silent: said, and read again.
	b.value = json.RawMessage(`{"text":"9.0 W CPU","at":"2026-10-08T12:01:00Z"}`)
	now = now.Add(Silent + time.Second)
	f.Round(bar)
	if b.gets != 1 || !strings.Contains(said[len(said)-1], "has said nothing") {
		t.Fatalf("gets %d, said %v", b.gets, said)
	}
	if got, _ := os.ReadFile(filepath.Join(dir, "power.draw@laptop")); string(got) != "9.0 W CPU\n" {
		t.Fatalf("%q", got)
	}
	// Not again while the watch speaks.
	if err := b.handles[Wanted{"power.draw", "laptop"}]("put", b.value); err != nil {
		t.Fatal(err)
	}
	f.Round(bar)
	if b.gets != 1 {
		t.Fatalf("read again while the watch speaks: %d", b.gets)
	}

	// Its block removed: the file goes, and what the watch still hands over is dropped.
	f.Round(barFiles(t, "no values here"))
	if _, err := os.Stat(filepath.Join(dir, "power.draw@laptop")); !os.IsNotExist(err) {
		t.Fatal("a value no bar shows is still kept")
	}
	if err := b.handles[Wanted{"power.draw", "laptop"}]("put", b.value); err != nil {
		t.Fatal(err)
	}
	if _, err := os.Stat(filepath.Join(dir, "power.draw@laptop")); !os.IsNotExist(err) {
		t.Fatal("a stopped watch still writes")
	}
	if !strings.Contains(said[len(said)-1], "no longer kept") {
		t.Fatalf("%v", said)
	}
}

func TestAKeyIsAMachinesName(t *testing.T) {
	if w := wantedIn(barFiles(t, `i3status-value power.draw ../etc`+"\n"+`i3status-value power.draw Laptop`)); len(w) != 0 {
		t.Fatalf("%v", w)
	}
}

func TestTheBlocksCommandShowsOnlyAFreshValue(t *testing.T) {
	runtime := t.TempDir()
	dir := filepath.Join(runtime, "i3status-rust", "values")
	run := func() string {
		cmd := exec.Command("sh", "../../files/bin/i3status-value", "power.draw", "laptop")
		cmd.Env = append(os.Environ(), "XDG_RUNTIME_DIR="+runtime)
		out, err := cmd.Output()
		if err != nil {
			t.Fatal(err)
		}
		return strings.TrimSpace(string(out))
	}
	if got := run(); got != "" {
		t.Fatalf("no value: %q", got)
	}
	fresh := time.Now().UTC().Format(time.RFC3339)
	if err := keep(dir, Wanted{"power.draw", "laptop"}, "put", json.RawMessage(`{"text":"8.0 W CPU","at":"`+fresh+`"}`)); err != nil {
		t.Fatal(err)
	}
	if got := run(); got != "8.0 W CPU" {
		t.Fatalf("fresh: %q", got)
	}
	// A value measured 31 s ago hides, however recently it arrived.
	old := time.Now().Add(-31 * time.Second).UTC().Format(time.RFC3339)
	if err := keep(dir, Wanted{"power.draw", "laptop"}, "put", json.RawMessage(`{"text":"8.0 W CPU","at":"`+old+`"}`)); err != nil {
		t.Fatal(err)
	}
	if got := run(); got != "" {
		t.Fatalf("measured 31 s ago: %q", got)
	}
}