package release

import (
	"context"
	"encoding/json"
	"errors"
	"testing"
)

func TestChangeScope(t *testing.T) {
	cases := map[string]string{
		"apps/bab/shop/instances/a.example.com.json": "apps/bab/shop",
		"apps/bab/shop/config-gen.json":              "apps/bab/shop",
		"apps/bab/shop/channels/canary/x":            "apps/bab/shop",
		"apps/bab/shop/sidecars.json":                "apps/bab/shop",
		"apps/bab/shop/schedules.json":               "apps/bab/shop",
		"accounts/bab/account.json":                  "accounts/bab",
		"accounts/bab/telemetry.json":                "accounts/bab",
		"control/certs/example.com":                  "control/certs",
		"control/edges/box-a.json":                   "control/edges",
	}
	for k, want := range cases {
		got, ok := ChangeScope(k)
		if !ok || got != want {
			t.Errorf("ChangeScope(%q) = %q,%v want %q", k, got, ok, want)
		}
	}
	for _, k := range []string{
		"apps/bab/shop/logs/box/2026-10-21-10/x", "apps/bab/shop/errors/x",
		"apps/bab/shop/analytics/x", "apps/bab/shop/runs/r1/request.json",
		"apps/bab/shop/metrics/x", "apps/bab/shop/schedule-status/shop.example.com.json",
		"apps/bab/shop", "apps/bab/", "apps/",
		ChangeIndexKey, "control/serial", "control/edge-mesh-key",
		"control/edge-mesh-key.next", "releases/x", "status/boxes/a.json",
		"fleets/f/apps/bab/shop/config.json",
	} {
		if s, ok := ChangeScope(k); ok {
			t.Errorf("ChangeScope(%q) = %q, want none", k, s)
		}
	}
}

// bumpFuncs adapts a Store to the raw get/put pair bumpChangeIndex takes.
func bumpFuncs(s Store) (func(context.Context, string) ([]byte, string, error), func(context.Context, string, []byte, string) (string, error)) {
	return s.Get, s.Put
}

func TestBumpChangeIndexCreatesThenIncrements(t *testing.T) {
	t.Parallel()
	ctx := context.Background()
	s := NewDirStore(t.TempDir())
	get, put := bumpFuncs(s)
	if err := bumpChangeIndex(ctx, get, put, "control/certs"); err != nil {
		t.Fatal(err)
	}
	for i := 0; i < 2; i++ {
		if err := bumpChangeIndex(ctx, get, put, "apps/bab/shop"); err != nil {
			t.Fatal(err)
		}
	}
	idx, etag, err := ReadChangeIndex(ctx, s)
	if err != nil {
		t.Fatal(err)
	}
	if etag == "" || idx.Schema != 1 {
		t.Fatalf("etag %q schema %d", etag, idx.Schema)
	}
	if idx.Entries["apps/bab/shop"] != 2 || idx.Entries["control/certs"] != 1 || len(idx.Entries) != 2 {
		t.Fatalf("entries = %v", idx.Entries)
	}
}

func TestBumpChangeIndexAppliesAllScopesInOneWrite(t *testing.T) {
	t.Parallel()
	ctx := context.Background()
	s := NewDirStore(t.TempDir())
	puts := 0
	get := s.Get
	put := func(ctx context.Context, k string, b []byte, m string) (string, error) {
		puts++
		return s.Put(ctx, k, b, m)
	}
	if err := bumpChangeIndex(ctx, get, put, "apps/bab/shop", "accounts/bab", "apps/bab/shop"); err != nil {
		t.Fatal(err)
	}
	idx, _, _ := ReadChangeIndex(ctx, s)
	if puts != 1 || idx.Entries["accounts/bab"] != 1 || idx.Entries["apps/bab/shop"] != 1 {
		t.Fatalf("puts %d entries %v", puts, idx.Entries)
	}
}

func TestBumpChangeIndexRetriesOnConflict(t *testing.T) {
	t.Parallel()
	ctx := context.Background()
	s := NewDirStore(t.TempDir())
	puts := 0
	put := func(ctx context.Context, k string, b []byte, m string) (string, error) {
		puts++
		if puts <= 2 {
			return "", ErrCASConflict
		}
		return s.Put(ctx, k, b, m)
	}
	if err := bumpChangeIndex(ctx, s.Get, put, "apps/bab/shop"); err != nil {
		t.Fatal(err)
	}
	idx, _, _ := ReadChangeIndex(ctx, s)
	if puts != 3 || idx.Entries["apps/bab/shop"] != 1 {
		t.Fatalf("puts %d entries %v", puts, idx.Entries)
	}
}

func TestBumpChangeIndexGivesUpAfterFourAttempts(t *testing.T) {
	t.Parallel()
	s := NewDirStore(t.TempDir())
	puts := 0
	put := func(context.Context, string, []byte, string) (string, error) {
		puts++
		return "", ErrCASConflict
	}
	err := bumpChangeIndex(context.Background(), s.Get, put, "apps/bab/shop")
	if err == nil || !errors.Is(err, ErrCASConflict) {
		t.Fatalf("err = %v", err)
	}
	if puts != 4 {
		t.Fatalf("puts = %d, want 4", puts)
	}
}

func TestBumpChangeIndexRefusesUnknownSchema(t *testing.T) {
	t.Parallel()
	ctx := context.Background()
	s := NewDirStore(t.TempDir())
	if _, err := s.Put(ctx, ChangeIndexKey, []byte(`{"schema":2,"entries":{}}`), ""); err != nil {
		t.Fatal(err)
	}
	puts := 0
	put := func(ctx context.Context, k string, b []byte, m string) (string, error) {
		puts++
		return s.Put(ctx, k, b, m)
	}
	err := bumpChangeIndex(ctx, s.Get, put, "apps/bab/shop")
	if !errors.Is(err, ErrChangeIndexSchema) || puts != 0 {
		t.Fatalf("err = %v, puts = %d", err, puts)
	}
}

func TestReadChangeIndexAbsentIsEmpty(t *testing.T) {
	t.Parallel()
	idx, etag, err := ReadChangeIndex(context.Background(), NewDirStore(t.TempDir()))
	if err != nil {
		t.Fatal(err)
	}
	if idx.Schema != 1 || idx.Entries == nil || len(idx.Entries) != 0 || etag != "" {
		t.Fatalf("idx %+v etag %q", idx, etag)
	}
}

func TestReadChangeIndexMalformedAndSchema(t *testing.T) {
	t.Parallel()
	ctx := context.Background()
	s := NewDirStore(t.TempDir())
	if _, err := s.Put(ctx, ChangeIndexKey, []byte(`not json`), ""); err != nil {
		t.Fatal(err)
	}
	if _, _, err := ReadChangeIndex(ctx, s); err == nil || errors.Is(err, ErrChangeIndexSchema) {
		t.Fatalf("malformed err = %v", err)
	}
	body, _ := json.Marshal(ChangeIndex{Schema: 3})
	if _, err := s.Put(ctx, ChangeIndexKey, body, mustEtag(t, s)); err != nil {
		t.Fatal(err)
	}
	if _, _, err := ReadChangeIndex(ctx, s); !errors.Is(err, ErrChangeIndexSchema) {
		t.Fatalf("schema err = %v", err)
	}
}

func mustEtag(t *testing.T, s Store) string {
	t.Helper()
	_, e, err := s.Get(context.Background(), ChangeIndexKey)
	if err != nil {
		t.Fatal(err)
	}
	return e
}