package tide

import (
	"bytes"
	"errors"
	"io/fs"
	"mime/multipart"
	"net/textproto"
	"os"
	"path/filepath"
	"strings"
	"testing"
)

// TestUpstreamSidecarRefusals covers the refusals of the sidecar loader,
// writer and multipart comparison that the replay tests do not reach: a
// missing, malformed or invalid sidecar is an error naming the file, a
// write that cannot validate or create its directory writes nothing, every
// part mismatch is reported, and an unresolved placeholder is an error.
func TestUpstreamSidecarRefusals(t *testing.T) {
	dir := t.TempDir()
	if _, err := LoadUpstream(filepath.Join(dir, "missing.upstream.yaml")); !errors.Is(err, fs.ErrNotExist) {
		t.Errorf("missing sidecar = %v", err)
	}
	write := func(name, body string) string {
		path := filepath.Join(dir, name)
		if err := os.WriteFile(path, []byte(body), 0o644); err != nil {
			t.Fatal(err)
		}
		return path
	}
	for name, body := range map[string]string{
		"unknown-field.yaml": "version: 1\nsurprise: true\n",
		"version.yaml":       "version: 9\n",
		"method.yaml":        "version: 1\nexchanges:\n  - request: {method: \" \", url: \"https://x.test/\"}\n    response: {status: 200}\n",
		"url.yaml":           "version: 1\nexchanges:\n  - request: {method: GET, url: \"/relative\"}\n    response: {status: 200}\n",
		"status.yaml":        "version: 1\nexchanges:\n  - request: {method: GET, url: \"https://x.test/\"}\n    response: {status: 42}\n",
	} {
		if _, err := LoadUpstream(write(name, body)); err == nil || !strings.Contains(err.Error(), name) {
			t.Errorf("%s = %v, want an error naming the file", name, err)
		}
	}

	store, err := OpenStore("")
	if err != nil {
		t.Fatal(err)
	}
	bad := UpstreamSidecar{Exchanges: []UpstreamExchange{{Request: UpstreamRequest{Method: "", URL: "https://x.test/"}, Response: UpstreamResponse{Status: 200}}}}
	if err := WriteUpstream(filepath.Join(dir, "bad.upstream.yaml"), bad, store); err == nil {
		t.Error("an invalid sidecar was written")
	}
	blocker := write("blocker", "a file, not a directory")
	good := UpstreamSidecar{Exchanges: []UpstreamExchange{{Request: UpstreamRequest{Method: "GET", URL: "https://x.test/"}, Response: UpstreamResponse{Status: 200}}}}
	if err := WriteUpstream(filepath.Join(blocker, "x.upstream.yaml"), good, store); err == nil {
		t.Error("a sidecar was written under a file")
	}
	path := filepath.Join(dir, "nested", "good.upstream.yaml")
	if err := WriteUpstream(path, good, store); err != nil {
		t.Fatal(err)
	}
	if s, err := LoadUpstream(path); err != nil || s.Version != CurrentVersion {
		t.Fatalf("written sidecar = %+v %v", s, err)
	}

	var body bytes.Buffer
	mw := multipart.NewWriter(&body)
	_ = mw.WriteField("title", "Bug")
	h := textproto.MIMEHeader{}
	h.Set("Content-Disposition", `form-data; name="file"; filename="s.png"`)
	h.Set("Content-Type", "image/png")
	fw, _ := mw.CreatePart(h)
	_, _ = fw.Write([]byte("png"))
	_ = mw.Close()
	ctype := mw.FormDataContentType()
	fake := NewUpstreamFake(UpstreamSidecar{}, store)
	got, err := upstreamParts(ctype, body.Bytes())
	if err != nil || len(got) != 2 {
		t.Fatalf("parts %+v %v", got, err)
	}
	for _, c := range []struct {
		name string
		want []UpstreamPart
		frag string
	}{
		{"count", got[:1], "want 1, got 2"},
		{"name", []UpstreamPart{{Name: "other", Value: "Bug"}, got[1]}, "name: want"},
		{"filename", []UpstreamPart{got[0], {Name: "file", Filename: "x.png", ContentType: "image/png", SHA256: got[1].SHA256}}, "filename"},
		{"content type", []UpstreamPart{got[0], {Name: "file", Filename: "s.png", ContentType: "image/jpeg", SHA256: got[1].SHA256}}, "content type"},
		{"sha256", []UpstreamPart{got[0], {Name: "file", Filename: "s.png", ContentType: "image/png", SHA256: strings.Repeat("0", 64)}}, "sha256"},
		{"value", []UpstreamPart{{Name: "title", Value: "Feature"}, got[1]}, "value differs"},
		{"placeholder", []UpstreamPart{{Name: "title", Value: "{{missing}}"}, got[1]}, "unresolved placeholder"},
	} {
		problems := fake.compareParts(c.want, ctype, body.Bytes())
		if len(problems) == 0 || !strings.Contains(strings.Join(problems, "; "), c.frag) {
			t.Errorf("%s mismatch reported %v", c.name, problems)
		}
	}
	if problems := fake.compareParts(got, "application/json", body.Bytes()); len(problems) != 1 || !strings.Contains(problems[0], "not multipart") {
		t.Errorf("a non-multipart body = %v", problems)
	}
	if problems := fake.compareParts(got, ctype, body.Bytes()); len(problems) != 0 {
		t.Errorf("identical parts = %v", problems)
	}
	if _, err := store.expandKeeping("{{absent}} and {{sha256:kept}}", isHashPlaceholder); err == nil || !strings.Contains(err.Error(), "absent") {
		t.Errorf("expandKeeping with a missing name = %v", err)
	}
	if out, err := store.expandKeeping("plain", isHashPlaceholder); err != nil || out != "plain" {
		t.Errorf("expandKeeping(plain) = %q %v", out, err)
	}
}