package main

import (
	"encoding/json"
	"fmt"
	"net/http"
	"net/http/httptest"
	"os"
	"regexp"
	"slices"
	"strings"
	"testing"
	"time"
)

// rest sends a request to the REST API with a token.
func rest(h http.Handler, token, method, path, body string, headers map[string]string) *httptest.ResponseRecorder {
	req := httptest.NewRequest(method, path, strings.NewReader(body))
	if token != "" {
		req.Header.Set("Authorization", "Bearer "+token)
	}
	for k, v := range headers {
		req.Header.Set(k, v)
	}
	rec := httptest.NewRecorder()
	h.ServeHTTP(rec, req)
	return rec
}

func TestRESTAuthAndScopes(t *testing.T) {
	a, _ := newTestApp(t)
	h := a.routes()
	if rec := rest(h, "", "GET", "/api/v1/status", "", nil); rec.Code != http.StatusUnauthorized {
		t.Fatalf("no token: %d", rec.Code)
	}
	_, read, _ := a.tokens.Create("reader", "read")
	_, change, _ := a.tokens.Create("changer", "change")
	if rec := rest(h, read, "GET", "/api/v1/status", "", nil); rec.Code != 200 || !strings.Contains(rec.Body.String(), `"uplink"`) {
		t.Fatalf("status: %d %s", rec.Code, rec.Body)
	}
	if rec := rest(h, read, "DELETE", "/api/v1/changes", "", nil); rec.Code != http.StatusForbidden {
		t.Fatalf("a read token discards: %d", rec.Code)
	}
	if rec := rest(h, read, "PATCH", "/api/v1/settings", `{}`, map[string]string{"If-Match": "x"}); rec.Code != http.StatusForbidden {
		t.Fatalf("a read token patches: %d", rec.Code)
	}
	if rec := rest(h, change, "DELETE", "/api/v1/changes", "", nil); rec.Code == http.StatusForbidden || rec.Code == http.StatusUnauthorized {
		t.Fatalf("discard: %d %s", rec.Code, rec.Body)
	}
	if rec := rest(h, read, "POST", "/api/v1/status", "", nil); rec.Code != http.StatusMethodNotAllowed {
		t.Fatalf("POST: %d", rec.Code)
	}
	req := httptest.NewRequest("GET", "/api/v1/status", nil)
	req.Header.Set("Authorization", "Bearer "+read)
	req.Header.Set("Origin", "https://evil.example")
	rec := httptest.NewRecorder()
	h.ServeHTTP(rec, req)
	if rec.Code != http.StatusForbidden {
		t.Fatalf("foreign origin: %d", rec.Code)
	}
}

func TestRESTSettings(t *testing.T) {
	a, sys := newTestApp(t)
	if data, err := os.ReadFile(sys.settingsPath()); err == nil {
		os.WriteFile(sys.confirmedPath(), data, 0o600)
	}
	h := a.routes()
	_, tok, _ := a.tokens.Create("changer", "change")
	rec := rest(h, tok, "GET", "/api/v1/settings", "", nil)
	if rec.Code != 200 {
		t.Fatalf("get: %d", rec.Code)
	}
	etag := rec.Header().Get("ETag")
	if etag == "" {
		t.Fatal("no ETag header")
	}
	patch := `{"system":{"hostName":"gw"}}`
	if rec := rest(h, tok, "PATCH", "/api/v1/settings", patch, nil); rec.Code != http.StatusBadRequest {
		t.Fatalf("without If-Match: %d", rec.Code)
	}
	if rec := rest(h, tok, "PATCH", "/api/v1/settings", patch, map[string]string{"If-Match": `"0000"`}); rec.Code != http.StatusConflict {
		t.Fatalf("stale ETag: %d %s", rec.Code, rec.Body)
	}
	if rec := rest(h, tok, "PATCH", "/api/v1/settings", `{"system":{"sshKeys":[]}}`, map[string]string{"If-Match": etag}); rec.Code != http.StatusBadRequest {
		t.Fatalf("refused patch: %d", rec.Code)
	}
	rec = rest(h, tok, "PATCH", "/api/v1/settings", patch, map[string]string{"If-Match": etag})
	if rec.Code != 200 || !strings.Contains(rec.Body.String(), `"saved": true`) || rec.Header().Get("ETag") == etag {
		t.Fatalf("patch: %d %s", rec.Code, rec.Body)
	}
	rec = rest(h, tok, "GET", "/api/v1/changes", "", nil)
	if !strings.HasPrefix(rec.Header().Get("Content-Type"), "text/plain") || !strings.Contains(rec.Body.String(), "gw") {
		t.Fatalf("changes: %s %s", rec.Header().Get("Content-Type"), rec.Body)
	}
}

func TestLogs(t *testing.T) {
	one := 0
	cases := []struct {
		q    logQuery
		want []string
		bad  bool
	}{
		{logQuery{Unit: "router-webui"}, []string{"--lines=100"}, false},
		{logQuery{}, nil, true},
		{logQuery{Unit: "sshd.service"}, []string{"--unit=sshd.service"}, false},
		{logQuery{Unit: "systemd-journald"}, nil, true},
		{logQuery{Unit: "getty@tty1"}, nil, true},
		{logQuery{Unit: "router-pppoe", Lines: 5, Since: "1 hour ago", Priority: "err", Grep: "LCP", Boot: &one},
			[]string{"--lines=5", "--unit=router-pppoe", "--since=1 hour ago", "--priority=err", "--grep=LCP", "--boot=0"}, false},
		{logQuery{Unit: "kernel"}, []string{"-k"}, false},
		{logQuery{Unit: "--vacuum-time=1s"}, nil, true},
		{logQuery{Unit: "a b"}, nil, true},
		{logQuery{Unit: "router-webui", Lines: 5000}, nil, true},
		{logQuery{Unit: "router-webui", Priority: "loud"}, nil, true},
		{logQuery{Unit: "router-webui", Since: "$(reboot)"}, nil, true},
	}
	for _, c := range cases {
		args, err := journalArgs(c.q)
		if (err != nil) != c.bad {
			t.Fatalf("%+v: error %v", c.q, err)
		}
		for _, w := range c.want {
			if !slices.Contains(args, w) {
				t.Errorf("%+v: %q missing from %q", c.q, w, args)
			}
		}
	}

	a, _ := newTestApp(t)
	h := a.routes()
	var got []string
	runJournal = func(name string, args ...string) (string, error) {
		got = append([]string{name}, args...)
		return "2026-10-31T22:16:08+0000 router pppd[1]: Connected", nil
	}
	t.Cleanup(func() { runJournal = command })
	_, tok, _ := a.tokens.Create("reader", "read")
	rec := rest(h, tok, "GET", "/api/v1/logs?unit=router-pppoe&lines=3&boot=-1", "", nil)
	if rec.Code != 200 || !strings.Contains(rec.Body.String(), "Connected") || !slices.Contains(got, "--boot=-1") || !slices.Contains(got, "--lines=3") {
		t.Fatalf("logs: %d %s %q", rec.Code, rec.Body, got)
	}
	if rec := rest(h, tok, "GET", "/api/v1/logs?lines=abc", "", nil); rec.Code != http.StatusBadRequest {
		t.Fatalf("bad number: %d", rec.Code)
	}
	if rec := rest(h, tok, "GET", "/api/v1/logs?unit=-x", "", nil); rec.Code != http.StatusBadRequest {
		t.Fatalf("bad unit: %d", rec.Code)
	}
	text, failed := call(t, h, tok, "get_logs", map[string]any{"unit": "router-webui", "grep": "x"})
	if failed || !strings.Contains(text, "Connected") || !slices.Contains(got, "--unit=router-webui") {
		t.Fatalf("mcp get_logs: %v %q", failed, text)
	}
}

func TestOpenAPI(t *testing.T) {
	a, _ := newTestApp(t)
	h := a.routes()
	rec := rest(h, "", "GET", "/api/openapi.json", "", nil)
	if rec.Code != 200 {
		t.Fatalf("spec: %d", rec.Code)
	}
	var spec struct {
		OpenAPI string                               `json:"openapi"`
		Paths   map[string]map[string]map[string]any `json:"paths"`
	}
	if err := json.Unmarshal(rec.Body.Bytes(), &spec); err != nil || spec.OpenAPI != "3.1.0" {
		t.Fatalf("spec: %v %s", err, spec.OpenAPI)
	}
	// Every tool has an operation (the two interfaces stay equal).
	ops := map[string]bool{}
	for _, methods := range spec.Paths {
		for _, op := range methods {
			ops[op["operationId"].(string)] = true
		}
	}
	for _, tool := range mcpTools {
		if !ops[tool.name] {
			t.Errorf("tool %s has no REST operation", tool.name)
		}
	}
	for _, rt := range apiRoutes {
		if spec.Paths[rt.path][strings.ToLower(rt.method)] == nil {
			t.Errorf("%s %s is not in the spec", rt.method, rt.path)
		}
	}
}

func TestTokenExpiry(t *testing.T) {
	a, _ := newTestApp(t)
	h := a.routes()
	tok, secret, err := a.tokens.CreateFor("short", "read", time.Hour)
	if err != nil || tok.Expires.IsZero() {
		t.Fatalf("create: %v %+v", err, tok)
	}
	if rec := rest(h, secret, "GET", "/api/v1/status", "", nil); rec.Code != 200 {
		t.Fatalf("valid token: %d", rec.Code)
	}
	// Move its end into the past.
	toks := a.tokens.load()
	toks[0].Expires = time.Now().Add(-time.Minute)
	if err := a.tokens.save(toks); err != nil {
		t.Fatal(err)
	}
	if rec := rest(h, secret, "GET", "/api/v1/status", "", nil); rec.Code != http.StatusUnauthorized {
		t.Fatalf("expired token: %d", rec.Code)
	}
	if rec, _ := rpc(h, secret, "ping", nil); rec.Code != http.StatusUnauthorized {
		t.Fatalf("expired token on MCP: %d", rec.Code)
	}
	_, forever, _ := a.tokens.Create("long", "read")
	if rec := rest(h, forever, "GET", "/api/v1/status", "", nil); rec.Code != 200 {
		t.Fatalf("token without expiry: %d", rec.Code)
	}
}

func TestTokenEditNote(t *testing.T) {
	a, sys := newTestApp(t)
	h := a.routes()
	data, _ := os.ReadFile(sys.settingsPath())
	os.WriteFile(sys.confirmedPath(), data, 0o600)
	_, tok, _ := a.tokens.Create("assistant", "change")
	rec := rest(h, tok, "GET", "/api/v1/settings", "", nil)
	e := rec.Header().Get("ETag")
	if rec := rest(h, tok, "PATCH", "/api/v1/settings", `{"system":{"hostName":"gw"}}`, map[string]string{"If-Match": e}); rec.Code != 200 {
		t.Fatalf("patch: %d %s", rec.Code, rec.Body)
	}
	cur, _ := os.ReadFile(sys.settingsPath())
	if note := sys.tokenEditNote(cur); !strings.Contains(note, "assistant") {
		t.Fatalf("no note: %q", note)
	}
	// A later edit by a person makes the note stale.
	other := append([]byte(nil), cur...)
	other = append(other, '\n', ' ')
	if note := sys.tokenEditNote(other); note != "" {
		t.Fatalf("stale note: %q", note)
	}
}

func TestAPIReference(t *testing.T) {
	a, _ := newTestApp(t)
	h := a.routes()
	if rec := do(h, "GET", "/apireference", nil, nil); rec.Code != http.StatusSeeOther {
		t.Fatalf("without a session: %d", rec.Code)
	}
	cookie := login(t, h)
	rec := do(h, "GET", "/apireference", nil, cookie)
	body := rec.Body.String()
	if rec.Code != 200 {
		t.Fatalf("reference: %d", rec.Code)
	}
	csp := rec.Header().Get("Content-Security-Policy")
	m := regexp.MustCompile(`data-nonce="([^"]+)"`).FindStringSubmatch(body)
	if m == nil || !strings.Contains(csp, "'nonce-"+m[1]+"'") {
		t.Errorf("the page's nonce is not in its CSP: %q", csp)
	}
	if strings.Contains(csp, "unsafe-inline") || strings.Contains(csp, "unsafe-eval") {
		t.Errorf("CSP too loose: %q", csp)
	}
	if !strings.Contains(body, `data-spec="/api/openapi.json"`) || !strings.Contains(body, "/static/redoc.standalone.js") {
		t.Errorf("the page does not load Redoc with the spec:\n%s", body)
	}
}

func TestSpecExplainsETags(t *testing.T) {
	spec := openAPISpec("1.2.3", nil, "router.example")
	info := spec["info"].(map[string]any)["description"].(string)
	for _, want := range []string{"ETag", "If-Match", "409"} {
		if !strings.Contains(info, want) {
			t.Errorf("%q is not explained in the spec's description", want)
		}
	}
	patch := spec["paths"].(map[string]any)["/api/v1/settings"].(map[string]any)["patch"].(map[string]any)
	if strings.Contains(patch["description"].(string), "update_settings") || strings.Contains(patch["description"].(string), "check_settings") {
		t.Errorf("REST description names an MCP tool: %v", patch["description"])
	}
	src := patch["x-codeSamples"].([]any)[0].(map[string]any)["source"].(string)
	if !strings.Contains(src, "https://router.example/api/v1/settings") || !strings.Contains(src, "If-Match") {
		t.Errorf("curl sample: %s", src)
	}
	get := spec["paths"].(map[string]any)["/api/v1/settings"].(map[string]any)["get"].(map[string]any)
	if _, ok := get["responses"].(map[string]any)["200"].(map[string]any)["headers"].(map[string]any)["ETag"]; !ok {
		t.Errorf("GET settings does not document its ETag header")
	}
}

// strs reads a string or a list of strings of a decoded schema.
func strs(v any) []string {
	switch x := v.(type) {
	case string:
		return []string{x}
	case []any:
		var out []string
		for _, e := range x {
			out = append(out, fmt.Sprint(e))
		}
		return out
	}
	return nil
}

// conforms checks a decoded JSON value against a schema of the OpenAPI
// document (the subset typeschema.go emits), resolving $ref in spec.
func conforms(v any, s map[string]any, spec map[string]any, path string) []string {
	if ref, ok := s["$ref"].(string); ok {
		name := strings.TrimPrefix(ref, "#/components/schemas/")
		def, _ := spec["components"].(map[string]any)["schemas"].(map[string]any)[name].(map[string]any)
		if def == nil {
			return []string{path + ": unknown schema " + name}
		}
		return conforms(v, def, spec, path)
	}
	if branches, ok := s["anyOf"].([]any); ok {
		for _, b := range branches {
			if len(conforms(v, b.(map[string]any), spec, path)) == 0 {
				return nil
			}
		}
		return []string{path + ": matches none of the alternatives"}
	}
	types := strs(s["type"])
	if len(types) == 0 {
		return nil // any
	}
	kind := "null"
	switch v.(type) {
	case bool:
		kind = "boolean"
	case string:
		kind = "string"
	case float64:
		kind = "number"
	case []any:
		kind = "array"
	case map[string]any:
		kind = "object"
	}
	if f, ok := v.(float64); ok && f == float64(int64(f)) && slices.Contains(types, "integer") {
		kind = "integer"
	}
	if !slices.Contains(types, kind) {
		return []string{path + ": is " + kind + ", the schema says " + strings.Join(types, " or ")}
	}
	var errs []string
	switch x := v.(type) {
	case string:
		if s["format"] == "date-time" {
			if _, err := time.Parse(time.RFC3339Nano, x); err != nil {
				errs = append(errs, path+": not a date-time: "+x)
			}
		}
		if enum := strs(s["enum"]); enum != nil && !slices.Contains(enum, x) {
			errs = append(errs, path+": "+x+" is not in the enum")
		}
	case []any:
		items, _ := s["items"].(map[string]any)
		for i, e := range x {
			errs = append(errs, conforms(e, items, spec, fmt.Sprintf("%s[%d]", path, i))...)
		}
	case map[string]any:
		props, _ := s["properties"].(map[string]any)
		{
			for _, k := range strs(s["required"]) {
				if _, ok := x[k]; !ok {
					errs = append(errs, path+": "+k+" is missing")
				}
			}
		}
		for k, c := range x {
			if p, ok := props[k].(map[string]any); ok {
				errs = append(errs, conforms(c, p, spec, path+"/"+k)...)
			} else if add, ok := s["additionalProperties"].(map[string]any); ok {
				errs = append(errs, conforms(c, add, spec, path+"/"+k)...)
			} else if props != nil {
				errs = append(errs, path+": "+k+" is not in the schema")
			}
		}
	}
	return errs
}

// What the API answers is what the OpenAPI document says it answers.
func TestResponsesMatchTheirSchemas(t *testing.T) {
	a, sys := newTestApp(t)
	if data, err := os.ReadFile(sys.settingsPath()); err == nil {
		os.WriteFile(sys.confirmedPath(), data, 0o600)
	}
	h := a.routes()
	_, tok, _ := a.tokens.Create("changer", "change")
	// Through JSON, as a client sees the document.
	var spec map[string]any
	data, _ := json.Marshal(openAPISpec("1.2.3", nil, "router.example"))
	json.Unmarshal(data, &spec)
	check := func(method, path, body string, headers map[string]string) {
		t.Helper()
		rec := rest(h, tok, method, path, body, headers)
		if rec.Code != 200 {
			t.Errorf("%s %s: %d %s", method, path, rec.Code, rec.Body)
			return
		}
		op := spec["paths"].(map[string]any)[path].(map[string]any)[strings.ToLower(method)].(map[string]any)
		content := op["responses"].(map[string]any)["200"].(map[string]any)["content"].(map[string]any)
		js, ok := content["application/json"].(map[string]any)
		if !ok {
			if _, text := content["text/plain"]; !text || !strings.HasPrefix(rec.Header().Get("Content-Type"), "text/plain") {
				t.Errorf("%s %s: documented %v, sent %s", method, path, content, rec.Header().Get("Content-Type"))
			}
			return
		}
		var v any
		if err := json.Unmarshal(rec.Body.Bytes(), &v); err != nil {
			t.Errorf("%s %s: %v", method, path, err)
			return
		}
		if errs := conforms(v, js["schema"].(map[string]any), spec, ""); len(errs) > 0 {
			t.Errorf("%s %s does not match its schema: %v\n%s", method, path, errs, rec.Body)
		}
	}
	for _, p := range []string{"/api/v1/status", "/api/v1/settings", "/api/v1/interfaces", "/api/v1/dhcp-leases", "/api/v1/update", "/api/v1/apply-log"} {
		check("GET", p, "", nil)
	}
	check("GET", "/api/v1/changes", "", nil)
	check("DELETE", "/api/v1/changes", "", nil)
	rec := rest(h, tok, "GET", "/api/v1/settings", "", nil)
	check("PATCH", "/api/v1/settings", `{"system":{"hostName":"gw"}}`, map[string]string{"If-Match": rec.Header().Get("ETag")})
}