package manifest_test

import (
	"slices"
	"strings"
	"testing"

	"github.com/BurntSushi/toml"

	"git.vakhrushev.me/av/convy/internal/manifest"
)

const projectSource = `# What this repository takes.
source = "../conventions"

# A component is a region where every chosen layer holds at once.
[components.backend]
dir = "backend/docs/conventions"
lang = ["go"]
topics = ["errors", "time"]

[components.web]
dir = "web/docs/conventions"
topics = [
  "client-logging",
]
`

func TestAddToListKeepsTheShapeOfTheArray(t *testing.T) {
	out, err := manifest.AddToList([]byte(projectSource), "components.backend", "topics", "logging")
	if err != nil {
		t.Fatal(err)
	}
	body := string(out)
	if !strings.Contains(body, `topics = ["errors", "logging", "time"]`) {
		t.Errorf("a sorted one-line array did not stay sorted and on one line:\n%s", body)
	}
	if !strings.Contains(body, "# A component is a region where every chosen layer holds at once.") {
		t.Errorf("the comment did not survive the edit:\n%s", body)
	}

	out, err = manifest.AddToList(out, "components.web", "topics", "auth")
	if err != nil {
		t.Fatal(err)
	}
	want := "topics = [\n  \"auth\",\n  \"client-logging\",\n]"
	if !strings.Contains(string(out), want) {
		t.Errorf("an array written down a column did not stay a column:\n%s", out)
	}
}

func TestAddToListCreatesTheKeyItDoesNotFind(t *testing.T) {
	out, err := manifest.AddToList([]byte(projectSource), "components.web", "stack", "express")
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(string(out), `stack = ["express"]`) {
		t.Errorf("the missing key was not created:\n%s", out)
	}
}

func TestAddToListRefusesWhatIsThereAlready(t *testing.T) {
	_, err := manifest.AddToList([]byte(projectSource), "components.backend", "topics", "time")
	if err == nil || !strings.Contains(err.Error(), "already holds") {
		t.Errorf("a repeated subscription went through: %v", err)
	}
	if _, err := manifest.AddToList([]byte(projectSource), "components.mobile", "topics", "time"); err == nil {
		t.Errorf("a table that is not there took an entry")
	}
}

func TestRemoveFromList(t *testing.T) {
	out, err := manifest.RemoveFromList([]byte(projectSource), "components.backend", "topics", "errors")
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(string(out), `topics = ["time"]`) {
		t.Errorf("the value was not removed:\n%s", out)
	}
	if _, err := manifest.RemoveFromList([]byte(projectSource), "components.backend", "topics", "logging"); err == nil {
		t.Errorf("removing what is not there went through")
	}
}

func TestAddTableGoesLast(t *testing.T) {
	out, err := manifest.AddTable([]byte(projectSource), "components.mobile",
		[][2]string{{"dir", `"mobile/docs/conventions"`}, {"topics", "[]"}})
	if err != nil {
		t.Fatal(err)
	}
	body := string(out)
	if !strings.Contains(body, "[components.mobile]\ndir = \"mobile/docs/conventions\"\ntopics = []") {
		t.Errorf("the table was not written:\n%s", body)
	}
	if strings.Index(body, "[components.mobile]") < strings.Index(body, "[components.web]") {
		t.Errorf("the new table did not go last:\n%s", body)
	}
	if _, err := manifest.AddTable(out, "components.mobile", nil); err == nil {
		t.Errorf("a second table of the same name went through")
	}
}

// The array is read the way the manifest wrote it. A # inside a string opens no
// comment, a bracket inside a comment closes no array, and a name inside a
// comment is not a subscription — turning any of the three into data is the one
// mistake there is no way back from.
func TestAddToListReadsCommentsAsComments(t *testing.T) {
	cases := []struct {
		name    string
		src     string
		add     string
		values  []string
		remains string
	}{{
		name:    "a name quoted inside a comment",
		src:     "[c.app]\ntopics = [\n  \"errors\",\n  # \"config\" is not taken yet\n]\n",
		add:     "time",
		values:  []string{"errors", "time"},
		remains: `# "config" is not taken yet`,
	}, {
		name:    "a bracket inside a comment",
		src:     "[c.app]\ntopics = [\n  \"errors\", # [enough for now]\n  \"db-schema\",\n]\n",
		add:     "config",
		values:  []string{"errors", "db-schema", "config"},
		remains: `"errors", # [enough for now]`,
	}, {
		name:    "a comment trailing a one-line array",
		src:     "[c.app]\ntopics = [\"git\"] # only git for now\n",
		add:     "time",
		values:  []string{"git", "time"},
		remains: `topics = ["git", "time"] # only git for now`,
	}, {
		name:    "a hash inside a value",
		src:     "[c.app]\ntopics = [\"a#b\"]\n",
		add:     "time",
		values:  []string{"a#b", "time"},
		remains: `topics = ["a#b", "time"]`,
	}}

	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			out, err := manifest.AddToList([]byte(tc.src), "c.app", "topics", tc.add)
			if err != nil {
				t.Fatal(err)
			}
			got := decodeTopics(t, out)
			if !slices.Equal(got, tc.values) {
				t.Errorf("the array holds %q, expected %q:\n%s", got, tc.values, out)
			}
			if !strings.Contains(string(out), tc.remains) {
				t.Errorf("what the author wrote is gone — no %q:\n%s", tc.remains, out)
			}
		})
	}
}

// decodeTopics reads the array back with the parser the tool itself uses.
func decodeTopics(t *testing.T, source []byte) []string {
	t.Helper()
	var got struct {
		C map[string]struct{ Topics []string } `toml:"c"`
	}
	if _, err := toml.Decode(string(source), &got); err != nil {
		t.Fatalf("the manifest the tool wrote does not parse: %v\n%s", err, source)
	}
	return got.C["app"].Topics
}

// A key is not always one line. Appending after the first line of an array
// written down a column would land the new entry inside it.
func TestAddToListAppendsPastAMultilineNeighbour(t *testing.T) {
	src := "[c.app]\ndir = \"docs\"\nstack = [\n  \"sqlite\",\n  \"postgres\",\n]\n"
	out, err := manifest.AddToList([]byte(src), "c.app", "topics", "errors")
	if err != nil {
		t.Fatal(err)
	}
	body := string(out)
	if !strings.Contains(body, "  \"postgres\",\n]\ntopics = [\"errors\"]") {
		t.Errorf("the new key did not land past the array:\n%s", body)
	}
}

// Whatever the tool writes into a manifest, it has to be able to read back.
func TestQuoteSurvivesTheRoundTrip(t *testing.T) {
	for _, value := range []string{`docs\conventions`, `a "quoted" name`, `both\ "kinds"`} {
		out, err := manifest.AddToList([]byte("[c.app]\ntopics = []\n"), "c.app", "topics", value)
		if err != nil {
			t.Fatal(err)
		}
		if list := decodeTopics(t, out); len(list) != 1 || list[0] != value {
			t.Errorf("%q came back as %q", value, list)
		}
	}
}