// Copyright 2026 Arctel.net
// SPDX-License-Identifier: Apache-2.0

package openresty

import (
	"strings"
	"testing"
)

func TestRenderOriginErrorPageEnabled(t *testing.T) {
	t.Parallel()
	doc := Document{
		Routes: []Route{{
			ID: 1, SiteName: "ex", Domains: []string{"ex.test"},
			OriginURL: "http://127.0.0.1:9", Enabled: true,
		}},
		OpenRestyConfig: ConfigSnapshot{
			OriginErrorPageEnabled:     true,
			OriginErrorPageStatusCodes: []string{"500-599"},
		},
	}
	out, err := RenderRouteConfig(doc, nil)
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(out, "proxy_intercept_errors on") {
		t.Fatal("missing intercept")
	}
	if !strings.Contains(out, "error_page") || !strings.Contains(out, "@__openflare_origin_error") {
		t.Fatal("missing error_page")
	}
	if !strings.Contains(out, "error_page 500") {
		t.Fatalf("expected expanded status codes in error_page, got:\n%s", out)
	}
	// Must NOT use `error_page … = @name` (adopts error-URI status → often 200).
	for _, line := range strings.Split(out, "\n") {
		trimmed := strings.TrimSpace(line)
		if strings.HasPrefix(trimmed, "error_page ") && strings.Contains(trimmed, " = ") {
			t.Fatalf("error_page must not use '=' form, got: %s", trimmed)
		}
	}
	if !strings.Contains(out, "error_page ") || !strings.Contains(out, " @__openflare_origin_error;") {
		t.Fatal("error_page must redirect to the named error location without '='")
	}
	if !strings.Contains(out, "location @__openflare_origin_error {") {
		t.Fatal("error location must be a named location (@...) that preserves the request method")
	}
	if strings.Contains(out, "location = /__openflare_origin_error") {
		t.Fatal("error location must NOT be a URI internal redirect (error_page URI redirects rewrite the method to GET, breaking the get_only gate)")
	}
	if !strings.Contains(out, "resolve_error_status") || !strings.Contains(out, "ngx.status = code") {
		t.Fatal("internal location must resolve and set ngx.status to the original error code")
	}
	if !strings.Contains(out, ErrorPageTmplPlaceholder) {
		t.Fatal("missing error page template placeholder")
	}
	res, err := Render(doc, nil)
	if err != nil {
		t.Fatal(err)
	}
	found := false
	for _, f := range res.SupportFiles {
		if f.Path == OriginErrorPageSupportPath {
			found = true
			if !strings.Contains(f.Content, "{{status}}") {
				t.Fatal("template missing placeholder")
			}
			if !strings.Contains(f.Content, "{{host}}") {
				t.Fatal("template missing host placeholder")
			}
		}
	}
	if !found {
		t.Fatal("missing support file")
	}
}

func TestRenderOriginErrorPageGetOnly(t *testing.T) {
	t.Parallel()
	doc := Document{
		Routes: []Route{{
			ID: 1, SiteName: "ex", Domains: []string{"ex.test"},
			OriginURL: "http://127.0.0.1:9", Enabled: true,
		}},
		OpenRestyConfig: ConfigSnapshot{
			OriginErrorPageEnabled:     true,
			OriginErrorPageStatusCodes: []string{"500-599"},
			OriginErrorPageGetOnly:     true,
		},
	}
	out, err := RenderRouteConfig(doc, nil)
	if err != nil {
		t.Fatal(err)
	}
	// Regression: GET-only must NOT intercept at the proxy level.
	// proxy_intercept_errors discards the upstream error body, so non-GET requests
	// would receive nginx's own default error page instead of the original
	// response (this was the reported bug: POST 503 returned OpenResty's page).
	if strings.Contains(out, "proxy_intercept_errors") {
		t.Fatal("get_only must not emit proxy_intercept_errors (it discards the upstream body for non-GET)")
	}
	// The body replacement must happen in Lua filters that only fire for GET.
	if !strings.Contains(out, "header_filter_by_lua_block") {
		t.Fatal("get_only must emit header_filter_by_lua_block inside the proxy location")
	}
	if !strings.Contains(out, "body_filter_by_lua_block") {
		t.Fatal("get_only must emit body_filter_by_lua_block inside the proxy location")
	}
	if !strings.Contains(out, `ngx.req.get_method() == "GET"`) {
		t.Fatal("Lua filter must replace the body only for GET requests")
	}
	if !strings.Contains(out, `ngx.ctx.openflare_error_html`) {
		t.Fatal("Lua filter must stash the error HTML in ngx.ctx for the body filter")
	}
	if !strings.Contains(out, `local codes = {500`) {
		t.Fatal("Lua filter must carry the expanded status codes")
	}
	if !strings.Contains(out, ErrorPageTmplPlaceholder) {
		t.Fatal("missing error page template placeholder")
	}
	// No error_page / named location machinery in GET-only mode.
	if strings.Contains(out, "error_page") {
		t.Fatal("get_only must not emit error_page (named-location path can only serve HTML or an empty status, never the original body)")
	}
	if strings.Contains(out, "@__openflare_origin_error") {
		t.Fatal("get_only must not emit the named error location")
	}
	// nginx rejects proxy_intercept_errors inside limit_except (only allow/deny
	// are valid there); GET-only must rely on Lua filters instead.
	if strings.Contains(out, "limit_except") {
		t.Fatal("get_only must not emit limit_except (proxy_intercept_errors is not allowed there)")
	}
	if strings.Contains(out, "location = /__openflare_origin_error") {
		t.Fatal("must not use URI internal redirect (rewrites method to GET, breaking the GET gate)")
	}
}

func TestRenderOriginErrorPageDisabled(t *testing.T) {
	t.Parallel()
	doc := Document{
		Routes: []Route{{
			ID: 1, SiteName: "ex", Domains: []string{"ex.test"},
			OriginURL: "http://127.0.0.1:9", Enabled: true,
		}},
		OpenRestyConfig: ConfigSnapshot{OriginErrorPageEnabled: false},
	}
	out, err := RenderRouteConfig(doc, nil)
	if err != nil {
		t.Fatal(err)
	}
	if strings.Contains(out, "proxy_intercept_errors") {
		t.Fatal("should not intercept when disabled")
	}
	if strings.Contains(out, "@__openflare_origin_error") {
		t.Fatal("should not emit error location when disabled")
	}
	res, err := Render(doc, nil)
	if err != nil {
		t.Fatal(err)
	}
	for _, f := range res.SupportFiles {
		if f.Path == OriginErrorPageSupportPath {
			t.Fatal("should not emit support file when disabled")
		}
	}
}

func TestRenderOriginErrorPageDefaultsEmptyHTMLAndStatusCodes(t *testing.T) {
	t.Parallel()
	doc := Document{
		Routes: []Route{{
			ID: 1, SiteName: "ex", Domains: []string{"ex.test"},
			OriginURL: "http://127.0.0.1:9", Enabled: true,
		}},
		OpenRestyConfig: ConfigSnapshot{
			OriginErrorPageEnabled: true,
		},
	}
	out, err := RenderRouteConfig(doc, nil)
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(out, "error_page 500") {
		t.Fatalf("empty status codes should default to 500-599, got:\n%s", out)
	}
	html := EffectiveOriginErrorPageHTML(doc.OpenRestyConfig)
	if html != DefaultOriginErrorPageHTML {
		t.Fatal("empty HTML should use default template")
	}
	if !strings.Contains(html, "{{status}}") || !strings.Contains(html, "{{host}}") {
		t.Fatal("default HTML must include placeholders")
	}
	if !strings.Contains(html, "OpenFlare") || !strings.Contains(html, "upstream server is unreachable") {
		t.Fatal("default HTML missing minimalist copy")
	}
}

func TestRenderOriginErrorPageCustomHTMLInSupportFile(t *testing.T) {
	t.Parallel()
	custom := "<html><body>custom {{status}} @ {{host}}</body></html>"
	doc := Document{
		Routes: []Route{{
			ID: 1, SiteName: "ex", Domains: []string{"ex.test"},
			OriginURL: "http://127.0.0.1:9", Enabled: true,
		}},
		OpenRestyConfig: ConfigSnapshot{
			OriginErrorPageEnabled:     true,
			OriginErrorPageStatusCodes: []string{"502"},
			OriginErrorPageHTML:        custom,
		},
	}
	res, err := Render(doc, nil)
	if err != nil {
		t.Fatal(err)
	}
	found := false
	for _, f := range res.SupportFiles {
		if f.Path == OriginErrorPageSupportPath {
			found = true
			if f.Content != custom {
				t.Fatalf("support file content = %q, want custom HTML", f.Content)
			}
		}
	}
	if !found {
		t.Fatal("missing support file")
	}
	out, err := RenderRouteConfig(doc, nil)
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(out, "error_page 502 @__openflare_origin_error;") {
		t.Fatalf("expected single 502 error_page without '=', got:\n%s", out)
	}
}

func TestRenderOriginErrorPageSkipsPagesRoutes(t *testing.T) {
	t.Parallel()
	doc := Document{
		Routes: []Route{{
			ID: 1, SiteName: "pages", Domains: []string{"pages.test"},
			UpstreamType: "pages", Enabled: true,
			PagesDeployment: &PagesDeployment{
				ProjectID: 1, LocalRoot: PagesDirPlaceholder + "/projects/1/current",
				EntryFile: "index.html",
			},
		}},
		OpenRestyConfig: ConfigSnapshot{
			OriginErrorPageEnabled:     true,
			OriginErrorPageStatusCodes: []string{"500-599"},
		},
	}
	out, err := RenderRouteConfig(doc, nil)
	if err != nil {
		t.Fatal(err)
	}
	if strings.Contains(out, "proxy_intercept_errors") {
		t.Fatal("pages routes must not get proxy_intercept_errors")
	}
	if strings.Contains(out, "@__openflare_origin_error") {
		t.Fatal("pages routes must not get origin error location")
	}
}