package handlers

import (
	"context"
	"html/template"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"github.com/go-chi/chi/v5"
)

func setupDocsTestHandler(t *testing.T) *Handler {
	t.Helper()
	h, cleanup := setupTestHandler(t)
	t.Cleanup(cleanup)

	docsDir := t.TempDir()
	if err := os.MkdirAll(filepath.Join(docsDir, "specs"), 0755); err != nil {
		t.Fatalf("failed to create specs dir: %v", err)
	}
	if err := os.MkdirAll(filepath.Join(docsDir, "plans"), 0755); err != nil {
		t.Fatalf("failed to create plans dir: %v", err)
	}
	if err := os.WriteFile(filepath.Join(docsDir, "specs", "2026-07-14-example-design.md"), []byte("# Example\n\nSome body text."), 0644); err != nil {
		t.Fatalf("failed to write fixture: %v", err)
	}

	h.config.DocsDir = docsDir
	return h
}

func TestHandleDocsIndex_ListsWhitelistedCategories(t *testing.T) {
	h := setupDocsTestHandler(t)

	req := httptest.NewRequest("GET", "/docs", nil)
	w := httptest.NewRecorder()
	h.HandleDocsIndex(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d", w.Code)
	}

	mock := h.renderer.(*MockRenderer)
	if len(mock.Calls) != 1 {
		t.Fatalf("expected 1 render call, got %d", len(mock.Calls))
	}
	if mock.Calls[0].Name != "docs-index.html" {
		t.Errorf("template name = %q, want %q", mock.Calls[0].Name, "docs-index.html")
	}

	data, ok := mock.Calls[0].Data.(struct{ Categories []docsCategoryListing })
	if !ok {
		t.Fatalf("unexpected data type: %T", mock.Calls[0].Data)
	}
	if len(data.Categories) != 2 {
		t.Fatalf("expected 2 categories (specs, plans), got %d", len(data.Categories))
	}
	specs := data.Categories[0]
	if specs.Name != "specs" {
		t.Fatalf("expected first category 'specs', got %q", specs.Name)
	}
	if len(specs.Entries) != 1 || specs.Entries[0].Name != "2026-07-14-example-design.md" {
		t.Fatalf("expected 1 spec entry, got %+v", specs.Entries)
	}
	if specs.Entries[0].URL != "/docs/specs/2026-07-14-example-design.md" {
		t.Errorf("URL = %q, want %q", specs.Entries[0].URL, "/docs/specs/2026-07-14-example-design.md")
	}

	plans := data.Categories[1]
	if plans.Name != "plans" || len(plans.Entries) != 0 {
		t.Fatalf("expected empty plans category, got %+v", plans)
	}
}

func routeWithParams(method, target, category, filename string) *http.Request {
	req := httptest.NewRequest(method, target, nil)
	rctx := chi.NewRouteContext()
	rctx.URLParams.Add("category", category)
	rctx.URLParams.Add("filename", filename)
	return req.WithContext(context.WithValue(req.Context(), chi.RouteCtxKey, rctx))
}

func TestHandleDocsView_RendersMarkdownFile(t *testing.T) {
	h := setupDocsTestHandler(t)

	req := routeWithParams("GET", "/docs/specs/2026-07-14-example-design.md", "specs", "2026-07-14-example-design.md")
	w := httptest.NewRecorder()
	h.HandleDocsView(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d", w.Code)
	}

	mock := h.renderer.(*MockRenderer)
	if len(mock.Calls) != 1 || mock.Calls[0].Name != "docs-view.html" {
		t.Fatalf("expected 1 call to docs-view.html, got %+v", mock.Calls)
	}
	data, ok := mock.Calls[0].Data.(struct {
		Title string
		Body  template.HTML
	})
	if !ok {
		t.Fatalf("unexpected data type: %T", mock.Calls[0].Data)
	}
	if data.Title != "2026-07-14-example-design.md" {
		t.Errorf("Title = %q, want %q", data.Title, "2026-07-14-example-design.md")
	}
	if !strings.Contains(string(data.Body), "<h1>Example</h1>") {
		t.Errorf("Body does not contain expected rendered heading: %s", data.Body)
	}
	if !strings.Contains(string(data.Body), "Some body text.") {
		t.Errorf("Body does not contain expected paragraph text: %s", data.Body)
	}
}

func TestHandleDocsView_RejectsUnknownCategory(t *testing.T) {
	h := setupDocsTestHandler(t)

	req := routeWithParams("GET", "/docs/other/2026-07-14-example-design.md", "other", "2026-07-14-example-design.md")
	w := httptest.NewRecorder()
	h.HandleDocsView(w, req)

	if w.Code != http.StatusNotFound {
		t.Errorf("expected 404 for unknown category, got %d", w.Code)
	}
}

func TestHandleDocsView_RejectsNonMarkdownFilename(t *testing.T) {
	h := setupDocsTestHandler(t)

	req := routeWithParams("GET", "/docs/specs/..", "specs", "..")
	w := httptest.NewRecorder()
	h.HandleDocsView(w, req)

	if w.Code != http.StatusNotFound {
		t.Errorf("expected 404 for a non-.md filename (e.g. '..'), got %d", w.Code)
	}
}

func TestHandleDocsView_RejectsMissingFile(t *testing.T) {
	h := setupDocsTestHandler(t)

	req := routeWithParams("GET", "/docs/specs/does-not-exist.md", "specs", "does-not-exist.md")
	w := httptest.NewRecorder()
	h.HandleDocsView(w, req)

	if w.Code != http.StatusNotFound {
		t.Errorf("expected 404 for a missing file, got %d", w.Code)
	}
}