package compose

import (
	"errors"
	"fmt"
	"os"
	"os/exec"
	"reflect"
	"slices"
	"strings"
	"testing"

	"github.com/lixenwraith/logwisp/internal/config"
)

// The engine builds as WebAssembly for the website: it links no TLS, HTTP,
// process, signal or terminal code, nor lw's log, auth or terminal modules
func TestEngineLinksNoHostCode(t *testing.T) {
	// A packager's -buildmode (makepkg's pie) is the host's; wasm has only the
	// default
	flags := slices.DeleteFunc(strings.Fields(os.Getenv("GOFLAGS")), func(f string) bool {
		return strings.HasPrefix(f, "-buildmode")
	})
	cmd := exec.Command("go", "list", "-deps", ".")
	cmd.Env = append(os.Environ(), "GOOS=js", "GOARCH=wasm", "GOFLAGS="+strings.Join(flags, " "))
	out, err := cmd.CombinedOutput()
	if err != nil {
		t.Fatalf("go list: %v\n%s", err, out)
	}
	for _, dep := range strings.Fields(string(out)) {
		module, mine := strings.CutPrefix(dep, "github.com/lixenwraith/")
		if slices.Contains([]string{"crypto/tls", "net/http", "os/exec", "os/signal", "golang.org/x/term"}, dep) ||
			mine && slices.Contains([]string{"log", "auth", "terminal"}, strings.Split(module, "/")[0]) {
			t.Errorf("links %s", dep)
		}
	}
}

// Every form a composition writes, its line ends LF or CRLF, and the
// website's JSON read back to it: escaped and quoted values, nested keys,
// lists, moved filters, stages whose flags' defaults differ from a file's, a
// value starting with '-', JSON's numbers for integers. The environment holds
// one pipeline, so each form is written from one or both.
func TestWrittenFormsReadBack(t *testing.T) {
	c := &Composition{}
	must := func(err error) {
		t.Helper()
		if err != nil {
			t.Fatal(err)
		}
	}
	must(c.AddPipeline("edge"))
	src, err := c.Add(0, "source", "file")
	must(err)
	must(c.Set(0, src, "directory", "/var/log/my app"))
	must(c.Set(0, src, "pattern", "it's *.log"))
	sink, err := c.Add(0, "sink", "tcp_chain")
	must(err)
	for key, value := range map[string]string{"host": "agg.example", "port": "9000", "tls.enabled": "true",
		"tls.pin_sha256": "sha256//" + strings.Repeat("A", 43) + "=", "auth.type": "scram",
		"auth.username": `edge,01=a\b\`, "auth.password_file": "/etc/lw/edge.pass"} {
		must(c.Set(0, sink, key, value))
	}
	exclude, err := c.Add(0, "filters", "exclude")
	must(err)
	must(c.Set(0, exclude, "patterns", `password=\S{8,64}`, `"quoted"`))
	include, err := c.Add(0, "filters", "include")
	must(err)
	must(c.Set(0, include, "patterns", "ERROR"))
	must(c.MoveFilter(0, 1, 0))
	must(c.Set(0, Node{Role: "rate_limit"}, "entries_per_second", "100"))
	must(c.Set(0, Node{Role: "heartbeat"}, "interval_ms", "5000"))
	must(c.Set(0, Node{Role: "heartbeat"}, "enabled", "true"))
	one := &Composition{Pipelines: slices.Clone(c.Pipelines)}
	must(c.AddPipeline("-b"))
	for _, role := range []string{"source", "sink"} {
		_, err = c.Add(1, role, "null")
		must(err)
	}
	must(c.Set(1, Node{Role: "heartbeat"}, "interval_ms", "2000"))
	for _, f := range Forms() {
		written := 0
		for _, c := range []*Composition{c, one} {
			text, err := f.Write(c)
			if err != nil {
				continue
			}
			written++
			for _, pasted := range []string{text, strings.ReplaceAll(text, "\n", "\r\n")} {
				if got, err := f.Read(pasted, nil); err != nil || !reflect.DeepEqual(got, c) {
					t.Fatalf("%s %q\n got %+v %v\nwant %+v", f.Name, pasted, got, err, c)
				}
			}
		}
		if written == 0 {
			t.Errorf("%s wrote neither composition", f.Name)
		}
	}
	data, err := c.JSON()
	must(err)
	if got, err := FromJSON(data); err != nil || !reflect.DeepEqual(got, c) {
		t.Fatalf("%s\n got %+v %v\nwant %+v", data, got, err, c)
	}
}

// Pasted environment text reads as a shell runs it: a comment line assigns
// nothing, export is no assignment, and a later assignment wins
func TestPastedEnvironmentReadsAsAShellRunsIt(t *testing.T) {
	c, err := FromEnvironment("export LOGWISP_SOURCE='null'\n# LOGWISP_SOURCE='tcp_chain'\n\nLOGWISP_SINK='tcp:port=1'\nLOGWISP_SINK='null'\n", nil)
	if err != nil {
		t.Fatal(err)
	}
	p := c.Pipelines[0]
	if len(c.Pipelines) != 1 || len(p.PluginSources) != 1 || p.PluginSources[0].Type != "null" || len(p.PluginSinks) != 1 || p.PluginSinks[0].Type != "null" {
		t.Fatalf("pipelines %+v", c.Pipelines)
	}
}

// Of a line piped into lw, lw's part is read, its pipeline reading standard
// input; a word that is no pipeline flag is refused, naming those to paste
func TestPastedCommandLineIsLwsPart(t *testing.T) {
	c, err := FromCommandLine("tail -F app.log | lw --filter include:patterns=ERROR", nil)
	if err != nil || c.Pipelines[0].PluginSources[0].Type != "console" || len(c.Pipelines[0].Flow.Filters) != 1 {
		t.Fatalf("%v %v", c, err)
	}
	if _, err := FromCommandLine("lw -c lw.toml --sink null", nil); err == nil || !strings.HasPrefix(err.Error(), "-c: not a pipeline flag; paste lw's --pipeline, --preset, ") {
		t.Fatalf("-c: %v", err)
	}
}

// Locate places a problem by its path: a plugin's key, a key of its table, a
// rule between its table's keys, a list entry, the plugin itself under an id
// holding ']', a filter's list entry, a stage and the pipeline; and nothing
// outside one
func TestLocatePlacesAProblem(t *testing.T) {
	sink := func(id string) Node { return Node{Role: "sink", ID: id} }
	for path, want := range map[string]struct {
		pi  int
		n   Node
		key string
	}{
		"pipelines[1].plugin_sinks[out].config.port":            {1, sink("out"), "port"},
		"pipelines[0].plugin_sinks[out].config.tls.min_version": {0, sink("out"), "tls.min_version"},
		"pipelines[0].plugin_sinks[out].config.tls":             {0, sink("out"), "tls"},
		"pipelines[0].plugin_sinks[out].config.acl.allow[1]":    {0, sink("out"), "acl.allow"},
		"pipelines[0].plugin_sinks[a]b].config":                 {0, sink("a]b"), ""},
		"pipelines[0].plugin_sources[in].type":                  {0, Node{Role: "source", ID: "in"}, "type"},
		"pipelines[0].flow.filters[2].patterns[1]":              {0, Node{Role: "filters", Index: 2}, "patterns"},
		"pipelines[0].flow.rate_limit.policy":                   {0, Node{Role: "rate_limit"}, "policy"},
		"pipelines[3].name":                                     {3, Node{}, "name"},
	} {
		pi, n, key, text, ok := Locate(fmt.Errorf("checked: %w", &config.KeyError{Key: path, Err: errors.New("wrong")}))
		if !ok || pi != want.pi || n != want.n || key != want.key || text != "wrong" {
			t.Errorf("%s: %d %+v %q %q %v", path, pi, n, key, text, ok)
		}
	}
	for _, err := range []error{errors.New("no pipelines configured"), &config.KeyError{Key: "color", Err: errors.New("wrong")}} {
		if _, _, _, text, ok := Locate(err); ok || text != err.Error() {
			t.Errorf("%v: placed, text %q", err, text)
		}
	}
}

// A null in the website's JSON is a value left unset, which every form then
// leaves out, in a table or a list
func TestANullInJSONIsUnset(t *testing.T) {
	with, err := FromJSON([]byte(`[{"name":"p","flow":{"rate_limit":null,"filters":[{"patterns":["a",null]}]},
		"plugin_sources":[{"type":"file","config":{"directory":"/x/","pattern":null}}],
		"plugin_sinks":[{"type":"console","config":{"color":null}}]}]`))
	if err != nil {
		t.Fatal(err)
	}
	without, err := FromJSON([]byte(`[{"name":"p","flow":{"filters":[{"patterns":["a"]}]},
		"plugin_sources":[{"type":"file","config":{"directory":"/x/"}}],"plugin_sinks":[{"type":"console"}]}]`))
	if err != nil || !reflect.DeepEqual(with, without) {
		t.Fatalf("%v\n got %+v\nwant %+v", err, with, without)
	}
}

// The website's JSON and a pasted file refuse a misspelled key as lw does,
// at any depth
func TestAMisspelledKeyIsRefused(t *testing.T) {
	for _, data := range []string{`[{"name":"p","plugin_source":[]}]`, `[{"name":"p","flow":{"rate_limt":{}}}]`} {
		if _, err := FromJSON([]byte(data)); err == nil || !strings.Contains(err.Error(), "unknown key") {
			t.Errorf("%s: %v", data, err)
		}
	}
	file := "[[pipelines]]\nname = \"p\"\nnmae = \"q\"\n[[pipelines.plugin_sources]]\ntype = \"null\"\n"
	if _, err := FromFile([]byte(file)); err == nil || !strings.Contains(err.Error(), `unknown key "pipelines[0].nmae"`) {
		t.Errorf("file: %v", err)
	}
}

// The command line and environment carry no control character, which a
// terminal acts on before the shell reads the paste; the file carries it
func TestShellFormsRefuseControlCharacters(t *testing.T) {
	c, err := FromPreset("tail", map[string]string{"path": "/srv/a\x15b/"}, nil)
	if err != nil {
		t.Fatal(err)
	}
	_, line := c.CommandLine()
	_, env := c.Environment()
	if _, err := c.File(); err != nil || line == nil || env == nil {
		t.Fatalf("command line %v, environment %v, file %v", line, env, err)
	}
}

// Set refuses a value of the wrong kind, a plugin's and a stage's alike, and
// leaves the key as it was; Unset leaves a key unset, dropping a table it
// leaves empty
func TestSetKeepsAKeyItCannotTake(t *testing.T) {
	c := &Composition{}
	if err := c.AddPipeline("p"); err != nil {
		t.Fatal(err)
	}
	n, _ := c.Add(0, "sink", "tcp")
	beat := Node{Role: "heartbeat"}
	for _, err := range []error{c.Set(0, n, "port", "8080"), c.Set(0, n, "tls.enabled", "true"),
		c.Unset(0, n, "tls.enabled"), c.Set(0, beat, "interval_ms", "5000"), c.Unset(0, beat, "interval_ms")} {
		if err != nil {
			t.Fatal(err)
		}
	}
	for want, err := range map[string]error{"port: not an integer": c.Set(0, n, "port", "http"),
		"interval_ms: not an integer": c.Set(0, beat, "interval_ms", "soon")} {
		if err == nil || err.Error() != want {
			t.Errorf("%v, want %s", err, want)
		}
	}
	if m, beat := c.Pipelines[0].PluginSinks[0].Config, c.Pipelines[0].Flow.Heartbeat; !reflect.DeepEqual(m, map[string]any{"port": int64(8080)}) ||
		beat.IntervalMS != 0 {
		t.Fatalf("options %v, heartbeat %+v", m, beat)
	}
}

// Options are a copy: changing them changes no pipeline; a stage that is off
// has none
func TestOptionsAreACopy(t *testing.T) {
	c := &Composition{}
	if err := c.AddPipeline("p"); err != nil {
		t.Fatal(err)
	}
	n, _ := c.Add(0, "sink", "tcp")
	if err := c.Set(0, n, "port", "9000"); err != nil {
		t.Fatal(err)
	}
	opts, on, err := c.Options(0, n)
	opts["port"] = int64(1)
	if _, rate, _ := c.Options(0, Node{Role: "rate_limit"}); err != nil || !on || rate || c.Pipelines[0].PluginSinks[0].Config["port"] != int64(9000) {
		t.Fatalf("%v %v %v %v", opts, on, rate, err)
	}
}

// A file may leave a source's or sink's id out: the engine names it as a
// spec would, around the ids the file gave, so the shell forms load back
func TestUnnamedPartsTakeFreeIDs(t *testing.T) {
	c, err := FromConfig(&config.Config{Pipelines: []config.PipelineConfig{{Name: "p",
		PluginSources: []config.PluginSourceConfig{{Type: "null"}, {ID: "null", Type: "null"}},
		PluginSinks:   []config.PluginSinkConfig{{Type: "null"}}}}})
	if err != nil {
		t.Fatal(err)
	}
	p := c.Pipelines[0]
	if ids := []string{p.PluginSources[0].ID, p.PluginSources[1].ID, p.PluginSinks[0].ID}; !slices.Equal(ids, []string{"null_2", "null", "null"}) {
		t.Fatalf("ids %q", ids)
	}
	line, err := c.CommandLine()
	if err == nil {
		_, err = FromCommandLine(line, nil)
	}
	if err != nil {
		t.Fatalf("%v\n%s", err, line)
	}
}

// Retype keeps the part's place and a chosen id, renames an automatic one,
// and carries the options of the same name and kind only within a side
func TestRetypeKeepsThePlace(t *testing.T) {
	c := &Composition{}
	if err := c.AddPipeline("p"); err != nil {
		t.Fatal(err)
	}
	for _, typ := range []string{"tcp", "http", "tcp"} {
		if _, err := c.Add(0, "sink", typ); err != nil {
			t.Fatal(err)
		}
	}
	tcp2, chosen := Node{Role: "sink", ID: "tcp_2"}, Node{Role: "sink", ID: "web"}
	c.Pipelines[0].PluginSinks[1].ID = chosen.ID
	for _, err := range []error{c.Set(0, tcp2, "port", "9000"), c.Set(0, tcp2, "keep_alive", "false"), c.Set(0, chosen, "port", "80")} {
		if err != nil {
			t.Fatal(err)
		}
	}
	got, err := c.Retype(0, tcp2, "http")
	if err != nil || got.ID != "http" {
		t.Fatalf("%+v %v", got, err)
	}
	if _, err := c.Retype(0, chosen, "tcp_chain"); err != nil {
		t.Fatal(err)
	}
	var parts []string
	for _, s := range c.Pipelines[0].PluginSinks {
		parts = append(parts, fmt.Sprintf("%s=%s %v", s.ID, s.Type, s.Config))
	}
	if want := []string{"tcp=tcp map[]", "web=tcp_chain map[]", "http=http map[port:9000]"}; !slices.Equal(parts, want) {
		t.Fatalf("%q, want %q", parts, want)
	}
}

// A pipeline takes a name no other has, renamed as when added
func TestPipelineNamesAreUnique(t *testing.T) {
	c := &Composition{}
	for _, name := range []string{"a", "b"} {
		if err := c.AddPipeline(name); err != nil {
			t.Fatal(err)
		}
	}
	if c.AddPipeline("a") == nil || c.RenamePipeline(1, "a") == nil || c.RenamePipeline(1, "") == nil {
		t.Fatal("took a name another pipeline has")
	}
	if err := c.RenamePipeline(1, "b"); err != nil || c.RenamePipeline(1, "c") != nil || c.Pipelines[1].Name != "c" {
		t.Fatalf("%v, %+v", err, c.Pipelines)
	}
}

// A stage an edit turns on does what its spec would: a rate limit drops what
// passes its rate, a heartbeat beats. A stage and a filter hold only the keys
// set, so the forms carry no default the edit did not set.
func TestAStageTurnsOnAsItsSpecDoes(t *testing.T) {
	c := &Composition{}
	if err := c.AddPipeline("p"); err != nil {
		t.Fatal(err)
	}
	_, err := c.Add(0, "filters", "")
	for _, err := range []error{err, c.Set(0, Node{Role: "rate_limit"}, "entries_per_second", "5"), c.Set(0, Node{Role: "heartbeat"}, "interval_ms", "500"),
		c.Set(0, Node{Role: "filters"}, "patterns", "x")} {
		if err != nil {
			t.Fatal(err)
		}
	}
	f := c.Pipelines[0].Flow
	if *f.RateLimit != (config.RateLimitConfig{EntriesPerSecond: 5, Policy: "drop"}) || *f.Heartbeat != (config.HeartbeatConfig{Enabled: true, IntervalMS: 500}) ||
		!reflect.DeepEqual(f.Filters, []config.FilterConfig{{Patterns: []string{"x"}}}) {
		t.Fatalf("%+v %+v %+v", f.RateLimit, f.Heartbeat, f.Filters)
	}
}

// A zero where zero takes the key's default is unset, as lw reads it; where
// zero means something of its own (retention_hours 0 keeps files), it stays
func TestAZeroTakingTheDefaultIsUnset(t *testing.T) {
	c, err := FromJSON([]byte(`[{"name":"p","plugin_sources":[{"type":"file","config":{"directory":"/x","check_interval_ms":0}}],
		"plugin_sinks":[{"type":"file","config":{"directory":"/y","name":"n","retention_hours":0}}]}]`))
	if err == nil {
		err = c.Set(0, Node{Role: "sink", ID: "file"}, "buffer_size", "0")
	}
	if src, sink := c.Pipelines[0].PluginSources[0].Config, c.Pipelines[0].PluginSinks[0].Config; err != nil ||
		!reflect.DeepEqual(src, map[string]any{"directory": "/x"}) || !reflect.DeepEqual(sink, map[string]any{"directory": "/y", "name": "n", "retention_hours": 0.0}) {
		t.Fatalf("%v %v %v", src, sink, err)
	}
}

// Text pasted as one form that has another's shape is refused as that form;
// text in no form's shape, or in this one's, gets this form's own refusal.
// The settings a file holds, and an environment's LOGWISP_ variables no
// pipeline flag has, are left out by name.
func TestAPasteIsReadAsItsForm(t *testing.T) {
	form := map[string]Form{}
	for _, f := range Forms() {
		form[f.Name] = f
	}
	for text, want := range map[[2]string]string{
		{"file", "lw --source null --sink null"}:         "this is an lw command line, not the pipelines of a configuration file: read it as the command form",
		{"command", "LOGWISP_SOURCE='null'\n"}:           "this is LOGWISP_ variables for one pipeline, not an lw command line: read it as the environment form",
		{"environment", "[[pipelines]]\nname = \"p\"\n"}: "this is the pipelines of a configuration file, not LOGWISP_ variables for one pipeline: read it as the file form",
		{"command", "lw -c lw.toml"}:                     "-c: not a pipeline flag",
		{"file", "hello world"}:                          "expected '=' after key",
	} {
		if _, err := form[text[0]].Parse(text[1], nil); err == nil || !strings.Contains(err.Error(), want) {
			t.Errorf("%s %q: %v", text[0], text[1], err)
		}
	}
	file, err := form["file"].Parse("quiet = true\n[logging]\nlevel = \"info\"\n[[pipelines]]\nname = \"p\"\n", nil)
	if err != nil || !slices.Equal(file.LeftOut, []string{"logging.level", "quiet"}) {
		t.Fatalf("file: %+v %v", file, err)
	}
	env, err := form["environment"].Parse("LOGWISP_SORCE_1='null'\nLOGWISP_QUIET=true\nLOGWISP_SINK=''\nLOGWISP_SOURCE_1=null\nHOME=/root\n", nil)
	if err != nil || !slices.Equal(env.LeftOut, []string{"LOGWISP_QUIET", "LOGWISP_SORCE_1"}) {
		t.Fatalf("environment: %+v %v", env, err)
	}
}