package hostclaim

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

	"github.com/carlosframework/platform/internal/release"
)

func TestReadRefusesMalformed(t *testing.T) {
	ctx := context.Background()
	s := release.NewDirStore(t.TempDir())
	obs, err := Read(ctx, s, testHost)
	if err != nil || !obs.Absent || obs.Host != testHost {
		t.Fatalf("absent read = %+v, %v", obs, err)
	}
	key, _ := Key(testHost)
	good := `{"v":2,"host":"` + testHost + `","gen":1,"op":{},"touched":{"complete":false}}`
	unknownChore := servingClaim(t, ctx, s).Claim
	unknownChore.Op = Op{Kind: KindParking, ID: "x"}
	unknownChore.Obligations = []Obligation{{ID: "o", Op: "x", Kind: "park-replica", Region: "ie", Retirement: "r", Owner: "region:ie"}}
	if err := unknownChore.Validate(); err != nil {
		t.Fatalf("invalid fixture before changing chore kind: %v", err)
	}
	unknownChore.Obligations[0].Kind = "teleport"
	unknownChoreBody, err := json.Marshal(unknownChore)
	if err != nil {
		t.Fatal(err)
	}
	for name, body := range map[string]string{
		"unknown field": `{"v":2,"host":"` + testHost + `","gen":1,"op":{},"touched":{"complete":false},"surprise":1}`,
		"trailing data": good + ` {"v":2}`,
		"wrong host":    `{"v":2,"host":"other.bab.oncarlos.com","gen":1,"op":{},"touched":{"complete":false}}`,
		"free with chores": `{"v":2,"host":"` + testHost + `","gen":1,"op":{},"touched":{"complete":false},` +
			`"obligations":[{"id":"o","op":"x","kind":"park-local","box":"b","retirement":"r","owner":"box:b"}]}`,
		"unknown chore kind": string(unknownChoreBody),
	} {
		s2 := release.NewDirStore(t.TempDir())
		if _, err := s2.Put(ctx, key, []byte(body), ""); err != nil {
			t.Fatal(err)
		}
		_, err := Read(ctx, s2, testHost)
		if name == "unknown chore kind" && (err == nil || !strings.Contains(err.Error(), `obligation kind "teleport"`)) {
			t.Errorf("%s: read = %v, want obligation-kind rejection", name, err)
		}
		if !errors.Is(err, ErrMalformed) {
			t.Errorf("%s: read = %v, want ErrMalformed", name, err)
		}
	}
}

func TestUpdateDerivesGenAndBindsHost(t *testing.T) {
	ctx := context.Background()
	s := release.NewDirStore(t.TempDir())
	obs, _ := Read(ctx, s, testHost)
	noop := func(c *Claim) error { return nil }
	o1, err := Update(ctx, s, obs, noop)
	if err != nil || o1.Claim.Gen != 1 || o1.Claim.Host != testHost {
		t.Fatalf("first write = %+v, %v", o1, err)
	}
	if _, err := Update(ctx, s, obs, noop); !errors.Is(err, ErrConflict) {
		t.Fatalf("stale absent write = %v, want ErrConflict (C5a)", err)
	}
	if _, err := Update(ctx, s, o1, func(c *Claim) error { c.Gen = 99; return nil }); !errors.Is(err, ErrMalformed) {
		t.Fatalf("transition changing gen = %v", err)
	}
	if _, err := Update(ctx, s, o1, func(c *Claim) error { c.Host = "other.bab.oncarlos.com"; return nil }); !errors.Is(err, ErrMalformed) {
		t.Fatalf("transition changing host = %v", err)
	}
	o2, err := Update(ctx, s, o1, noop)
	if err != nil || o2.Claim.Gen != 2 {
		t.Fatalf("second write = %+v, %v", o2, err)
	}
	if _, err := Update(ctx, s, o1, noop); !errors.Is(err, ErrConflict) {
		t.Fatalf("stale etag write = %v, want ErrConflict", err)
	}
}

func TestUpdateRejectsNonAbsentObservationWithoutETag(t *testing.T) {
	ctx := context.Background()
	s := release.NewDirStore(t.TempDir())
	obs := Observed{
		Host:   testHost,
		Claim:  &Claim{V: 2, Host: testHost, Gen: 1},
		Absent: false,
		ETag:   "",
	}
	if err := obs.Claim.Validate(); err != nil {
		t.Fatalf("invalid test claim: %v", err)
	}
	transitionCalled := false
	_, err := Update(ctx, s, obs, func(c *Claim) error {
		transitionCalled = true
		return nil
	})
	if !errors.Is(err, ErrMalformed) {
		t.Errorf("Update = %v, want ErrMalformed", err)
	}
	if transitionCalled {
		t.Error("transition called for observation without ETag")
	}
	after, err := Read(ctx, s, testHost)
	if err != nil || !after.Absent {
		t.Errorf("read after rejected update = %+v, %v; want absent", after, err)
	}
}