package web

import (
	"io"
	"log/slog"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	llmgw "gitea.mynodes.xyz/ilker/llmgw"
	"gitea.mynodes.xyz/ilker/llmgw/internal/store"
)

// docsMux mounts the portal the way the router does.
func docsMux(h http.HandlerFunc) *http.ServeMux {
	mux := http.NewServeMux()
	mux.HandleFunc("GET /docs", h)
	mux.HandleFunc("GET /docs/{doc}", h)
	return mux
}

func TestTheDocsPortalRendersADocumentWithItsHeadingsAndCode(t *testing.T) {
	code, body := get(t, docsMux(Docs("v1", false)), "/docs/clients", nil)
	if code != http.StatusOK {
		t.Fatalf("status %d", code)
	}
	for _, want := range []string{
		`<h1 id="using-llmgw-from-code">Using llmgw from code`,
		// A heading links to itself, for someone sending a section to someone.
		`<h2 id="streaming">Streaming<a href="#streaming"`,
		// Fenced code keeps its language, and its text is escaped, not markup.
		`<pre><code class="language-python">`,
		`client.chat.completions.create(`,
		// Tables are GitHub's.
		`<table>`,
		// The sidebar offers every document and marks the open one.
		`<a href="/docs/clients" aria-current="page">Using llmgw from code</a>`,
		`<a href="/docs/reference">`,
		// And this document's sections beneath it.
		`<a href="#the-anthropic-sdk">The Anthropic SDK</a>`,
	} {
		if !strings.Contains(body, want) {
			t.Errorf("the page lacks %q", want)
		}
	}
}

func TestEveryDocumentInTheManualIsAPage(t *testing.T) {
	h := docsMux(Docs("v1", false))
	for _, d := range llmgw.Manual() {
		if code, _ := get(t, h, "/docs/"+d.Key, nil); code != http.StatusOK {
			t.Errorf("/docs/%s: %d", d.Key, code)
		}
	}
}

func TestTheIndexLeadsWithTheClientGuide(t *testing.T) {
	code, body := get(t, docsMux(Docs("v1", true)), "/docs", nil)
	if code != http.StatusOK {
		t.Fatalf("status %d", code)
	}
	lead := strings.Index(body, `<a href="/docs/clients">Using llmgw from code</a> shows`)
	every := strings.Index(body, "Every document")
	if lead < 0 || every < 0 || lead > every {
		t.Errorf("the client guide is not offered first:\n%s", body)
	}
	if !strings.Contains(body, `<a href="/login">Sign in</a>`) {
		t.Error("a gateway with accounts does not offer to sign in")
	}
}

func TestLinksBetweenDocumentsStayInThePortal(t *testing.T) {
	paths := map[string]string{"docs/install.md": "install", "docs/guardrails.md": "guardrails",
		"README.md": "readme", "CHANGELOG.md": "changes"}
	src := "See [install](install.md), [a section](install.md#2-the-control-plane), " +
		"[here](#local), [the readme](../README.md), [proxies](../deploy/proxy/), " +
		"[the plan](llmgw-plan.md) and [elsewhere](https://example.com/x.md).\n"
	body, _ := renderDoc(src, "docs/guardrails.md", paths)
	for _, want := range []string{
		`href="/docs/install"`,
		`href="/docs/install#2-the-control-plane"`,
		`href="#local"`,
		`href="/docs/readme"`,
		// Not in the binary: the repository has it.
		`href="` + repoURL + `/src/branch/main/deploy/proxy/"`,
		`href="` + repoURL + `/src/branch/main/docs/llmgw-plan.md"`,
		`href="https://example.com/x.md"`,
	} {
		if !strings.Contains(string(body), want) {
			t.Errorf("rendered without %s:\n%s", want, body)
		}
	}
	// The README links into docs/ from the repository's root.
	body, _ = renderDoc("[guardrails](docs/guardrails.md)\n", "README.md", paths)
	if !strings.Contains(string(body), `href="/docs/guardrails"`) {
		t.Errorf("a link from the README: %s", body)
	}
}

func TestNoEmbeddedDocumentLinksToAPageThePortalLacks(t *testing.T) {
	// Every link a document makes into /docs/ must land on a page, or the
	// portal ships its own 404s.
	keys := map[string]bool{}
	for _, d := range manual() {
		keys[d.Key] = true
	}
	for _, d := range manual() {
		for _, part := range strings.Split(string(d.Body), `href="/docs/`)[1:] {
			key := part[:strings.IndexAny(part, `"#`)]
			if !keys[key] {
				t.Errorf("%s links to /docs/%s, which is not a page", d.Key, key)
			}
		}
	}
}

func TestAnUnknownDocumentIsNotFound(t *testing.T) {
	h := docsMux(Docs("v1", false))
	for _, path := range []string{"/docs/no-such-doc", "/docs/..%2fgo.mod", "/docs/BACKLOG"} {
		if code, _ := get(t, h, path, nil); code != http.StatusNotFound {
			t.Errorf("%s: %d, want 404", path, code)
		}
	}
	// The file name works as well as the key: it is what the documents say.
	if code, _ := get(t, h, "/docs/install.md", nil); code != http.StatusOK {
		t.Errorf("/docs/install.md: %d", code)
	}
}

func TestTheDocsCarryThePolicyAndNoScript(t *testing.T) {
	for _, path := range []string{"/docs", "/docs/clients", "/docs/reference", "/docs/readme"} {
		rec := httptest.NewRecorder()
		docsMux(Docs("v1", false)).ServeHTTP(rec, httptest.NewRequest("GET", path, nil))
		csp := rec.Header().Get("Content-Security-Policy")
		if !strings.Contains(csp, "script-src 'self';") || strings.Contains(csp, "sha256-") {
			t.Errorf("%s: policy %q, want this server's scripts and no inline one", path, csp)
		}
		if strings.Contains(strings.ToLower(rec.Body.String()), "<script") {
			t.Errorf("%s emits a script", path)
		}
	}
}

func TestTheDocsCanRequireSigningIn(t *testing.T) {
	a := fakeAccounts{user: store.User{ID: "u1", Email: "a@example.com"}}
	p := NewAccountPages(a, nil, nil, "v0", slog.New(slog.NewTextHandler(io.Discard, nil)))

	required := docsMux(p.DocsPage(Docs("v0", true), true))
	rec := httptest.NewRecorder()
	required.ServeHTTP(rec, httptest.NewRequest("GET", "/docs/install", nil))
	if rec.Code != http.StatusSeeOther || rec.Header().Get("Location") != "/login" {
		t.Errorf("without a session: %d to %q, want a redirect to /login", rec.Code, rec.Header().Get("Location"))
	}
	signedIn := mirrorGet(t, required, "/docs/install")
	if signedIn.Code != http.StatusOK {
		t.Fatalf("signed in: %d", signedIn.Code)
	}
	// Signed in, the page draws the portal's menu with Docs marked.
	if menu := menuRe.FindString(signedIn.Body.String()); !strings.Contains(menu, `aria-current="page">Docs<`) ||
		!strings.Contains(menu, `"/logout"`) {
		t.Errorf("the signed-in menu:\n%s", menu)
	}
	if !strings.Contains(signedIn.Header().Get("Cache-Control"), "no-store") {
		t.Error("a page with someone's menu on it may be cached")
	}

	public := docsMux(p.DocsPage(Docs("v0", true), false))
	rec = httptest.NewRecorder()
	public.ServeHTTP(rec, httptest.NewRequest("GET", "/docs/install", nil))
	if rec.Code != http.StatusOK || strings.Contains(rec.Body.String(), `"/logout"`) {
		t.Errorf("public, without a session: %d", rec.Code)
	}
}