package journal

import (
	"bytes"
	"log/slog"
	"strings"
	"sync"
	"testing"

	"git.golem15.com/golem15/sm-journal-plugin/classes"
	"git.golem15.com/golem15/summercms/modules/backpack"
	"git.golem15.com/golem15/summercms/modules/compass"
	"git.golem15.com/golem15/summercms/modules/cooler"
)

const siteCacheKeysToken = "journal-site-cache-keys-token-0123456789"

type keysLogBuffer struct {
	mu  sync.Mutex
	buf bytes.Buffer
}

func (b *keysLogBuffer) Write(p []byte) (int, error) {
	b.mu.Lock()
	defer b.mu.Unlock()
	return b.buf.Write(p)
}

func (b *keysLogBuffer) lines() []string {
	b.mu.Lock()
	defer b.mu.Unlock()
	var out []string
	for _, l := range strings.Split(strings.TrimSpace(b.buf.String()), "\n") {
		if l != "" {
			out = append(out, l)
		}
	}
	return out
}

// siteCacheApp returns an app on a config without a database holding values,
// with slog.Default captured for the test.
func siteCacheApp(t *testing.T, values map[string]string) (*backpack.App, *keysLogBuffer) {
	t.Helper()
	cfg, err := compass.Open(compass.Options{Dir: t.TempDir(), Environ: []string{}})
	if err != nil {
		t.Fatal(err)
	}
	for k, v := range values {
		if err := cfg.Set(k, v); err != nil {
			t.Fatal(err)
		}
	}
	buf := &keysLogBuffer{}
	prev := slog.Default()
	slog.SetDefault(slog.New(slog.NewTextHandler(buf, nil)))
	t.Cleanup(func() { slog.SetDefault(prev) })
	return backpack.New(cfg), buf
}

func assertNoPurgeToken(t *testing.T, lines []string) {
	t.Helper()
	for _, l := range lines {
		if strings.Contains(l, siteCacheKeysToken) {
			t.Fatalf("log line carries the token: %s", l)
		}
	}
}

func TestSiteCacheFrameworkKeysWin(t *testing.T) {
	framework := map[string]string{
		cooler.SiteCachePurgeURLKey:   "http://127.0.0.1:3000/api/__site__/cache/purge",
		cooler.SiteCachePurgeTokenKey: siteCacheKeysToken,
	}

	t.Run("framework keys only: the Journal publishes nothing and stays quiet", func(t *testing.T) {
		app, logs := siteCacheApp(t, framework)
		if err := (&Plugin{}).wireSiteCache(app); err != nil {
			t.Fatal(err)
		}
		if p, ok := app.Lookup[*cooler.SiteCachePurger](); ok && p != nil {
			t.Fatal("the Journal published a purger although the framework keys are set")
		}
		if lines := logs.lines(); len(lines) != 0 {
			t.Fatalf("log = %q, want nothing", lines)
		}
		// The framework builds the purger from its own keys.
		if p := cooler.SiteCacheFromApp(app); p == nil || p.Endpoint() != "127.0.0.1:3000/api/__site__/cache/purge" {
			t.Fatalf("cooler.SiteCacheFromApp = %v", p)
		}
	})

	t.Run("alias keys too: one warning that they are ignored", func(t *testing.T) {
		values := map[string]string{
			classes.SiteCachePurgeURLKey:   "http://127.0.0.1:4000/purge",
			classes.SiteCachePurgeTokenKey: "x", // invalid, but ignored
		}
		for k, v := range framework {
			values[k] = v
		}
		app, logs := siteCacheApp(t, values)
		if err := (&Plugin{}).wireSiteCache(app); err != nil {
			t.Fatalf("ignored alias keys must not fail boot: %v", err)
		}
		if p, ok := app.Lookup[*cooler.SiteCachePurger](); ok && p != nil {
			t.Fatal("the Journal published a purger from ignored keys")
		}
		lines := logs.lines()
		if len(lines) != 1 || !strings.Contains(lines[0], "level=WARN") || !strings.Contains(lines[0], "ignored") ||
			!strings.Contains(lines[0], cooler.SiteCachePurgeURLKey) {
			t.Fatalf("log = %q, want one warning naming the framework keys", lines)
		}
		assertNoPurgeToken(t, lines)
	})

	t.Run("only the framework token set still counts as framework keys", func(t *testing.T) {
		app, _ := siteCacheApp(t, map[string]string{
			cooler.SiteCachePurgeTokenKey:  siteCacheKeysToken,
			classes.SiteCachePurgeURLKey:   "http://127.0.0.1:4000/purge",
			classes.SiteCachePurgeTokenKey: siteCacheKeysToken,
		})
		if err := (&Plugin{}).wireSiteCache(app); err != nil {
			t.Fatal(err)
		}
		if p, ok := app.Lookup[*cooler.SiteCachePurger](); ok && p != nil {
			t.Fatal("alias keys were used although a framework key is set")
		}
	})
}

func TestSiteCacheAliasKeysDeprecated(t *testing.T) {
	t.Run("valid alias keys publish a purger with one deprecation warning", func(t *testing.T) {
		app, logs := siteCacheApp(t, map[string]string{
			classes.SiteCachePurgeURLKey:   "http://127.0.0.1:4000/api/__site__/cache/purge",
			classes.SiteCachePurgeTokenKey: siteCacheKeysToken,
		})
		if err := (&Plugin{}).wireSiteCache(app); err != nil {
			t.Fatal(err)
		}
		p, ok := app.Lookup[*cooler.SiteCachePurger]()
		if !ok || p == nil || p.Endpoint() != "127.0.0.1:4000/api/__site__/cache/purge" {
			t.Fatalf("published purger = %v", p)
		}
		if got := cooler.SiteCacheFromApp(app); got != p {
			t.Fatal("cooler.SiteCacheFromApp did not return the alias purger")
		}
		lines := logs.lines()
		if len(lines) != 1 || !strings.Contains(lines[0], "level=WARN") || !strings.Contains(lines[0], "deprecated") ||
			!strings.Contains(lines[0], cooler.SiteCachePurgeURLKey) || !strings.Contains(lines[0], cooler.SiteCachePurgeTokenKey) {
			t.Fatalf("log = %q, want one deprecation warning naming both framework keys", lines)
		}
		assertNoPurgeToken(t, lines)
	})

	for _, tc := range []struct {
		name, url, token, key string
	}{
		{"only the alias URL", "http://127.0.0.1:4000/purge", "", classes.SiteCachePurgeTokenKey},
		{"only the alias token", "", siteCacheKeysToken, classes.SiteCachePurgeURLKey},
		{"http to a remote host", "http://example.test/purge", siteCacheKeysToken, classes.SiteCachePurgeURLKey},
		{"a short token", "http://127.0.0.1:4000/purge", "short", classes.SiteCachePurgeTokenKey},
	} {
		t.Run("invalid alias keys fail boot: "+tc.name, func(t *testing.T) {
			app, _ := siteCacheApp(t, map[string]string{
				classes.SiteCachePurgeURLKey:   tc.url,
				classes.SiteCachePurgeTokenKey: tc.token,
			})
			err := (&Plugin{}).wireSiteCache(app)
			if err == nil || !strings.Contains(err.Error(), tc.key) {
				t.Fatalf("wireSiteCache = %v, want an error naming %s", err, tc.key)
			}
			if tc.token != "" && strings.Contains(err.Error(), tc.token) {
				t.Fatalf("error %q carries the token", err)
			}
			if p, ok := app.Lookup[*cooler.SiteCachePurger](); ok && p != nil {
				t.Fatal("an invalid alias configuration published a purger")
			}
		})
	}

	t.Run("an already published purger is kept", func(t *testing.T) {
		app, _ := siteCacheApp(t, map[string]string{
			classes.SiteCachePurgeURLKey:   "http://127.0.0.1:4000/purge",
			classes.SiteCachePurgeTokenKey: siteCacheKeysToken,
		})
		first, err := cooler.NewSiteCachePurger("http://127.0.0.1:5000/purge", siteCacheKeysToken)
		if err != nil {
			t.Fatal(err)
		}
		if err := app.Publish(first); err != nil {
			t.Fatal(err)
		}
		if err := (&Plugin{}).wireSiteCache(app); err != nil {
			t.Fatal(err)
		}
		if got, _ := app.Lookup[*cooler.SiteCachePurger](); got != first {
			t.Fatal("wireSiteCache replaced a published purger")
		}
	})
}

func TestSiteCacheNoKeys(t *testing.T) {
	app, logs := siteCacheApp(t, nil)
	if err := (&Plugin{}).wireSiteCache(app); err != nil {
		t.Fatal(err)
	}
	if p, ok := app.Lookup[*cooler.SiteCachePurger](); ok && p != nil {
		t.Fatal("no keys published a purger")
	}
	if p := cooler.SiteCacheFromApp(app); p != nil {
		t.Fatalf("cooler.SiteCacheFromApp = %v, want nil", p)
	}
	if lines := logs.lines(); len(lines) != 0 {
		t.Fatalf("log = %q, want nothing", lines)
	}
	if err := (&Plugin{}).wireSiteCache(nil); err != nil {
		t.Fatalf("wireSiteCache(nil) = %v", err)
	}
	if err := (&Plugin{}).wireSiteCache(backpack.New(nil)); err != nil {
		t.Fatalf("wireSiteCache(no config) = %v", err)
	}
}