package maphandler

import (
	"context"
	"net/http"
	"net/http/httptest"
	"reflect"
	"strings"
	"testing"

	"github.com/caddyserver/caddy/v2"
	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
)

func TestValidateDuplicateInputs(t *testing.T) {
	for _, tc := range []struct {
		name    string
		first   Mapping
		second  Mapping
		wantErr bool
	}{
		{name: "duplicate literals", first: Mapping{Input: "/abc"}, second: Mapping{Input: "/abc"}, wantErr: true},
		{name: "duplicate regexps", first: Mapping{InputRegexp: "/abc"}, second: Mapping{InputRegexp: "/abc"}, wantErr: true},
		{name: "literal then regexp", first: Mapping{Input: "/abc"}, second: Mapping{InputRegexp: "/abc"}},
		{name: "regexp then literal", first: Mapping{InputRegexp: "/abc"}, second: Mapping{Input: "/abc"}},
	} {
		t.Run(tc.name, func(t *testing.T) {
			tc.first.Outputs = []any{"first"}
			tc.second.Outputs = []any{"second"}
			h := Handler{
				Destinations: []string{"{output}"},
				Mappings:     []Mapping{tc.first, tc.second},
			}
			err := h.Validate()
			if tc.wantErr {
				if err == nil || !strings.Contains(err.Error(), "duplicate input '/abc'") {
					t.Fatalf("expected duplicate input error, got %v", err)
				}
			} else if err != nil {
				t.Fatalf("unexpected validation error: %v", err)
			}
		})
	}
}

func TestProvisionDestinations(t *testing.T) {
	for _, tc := range []struct {
		name        string
		destination string
		want        string
		wantErr     bool
	}{
		{name: "valid placeholder", destination: "{output}", want: "output"},
		{name: "trailing text", destination: "{output}suffix", wantErr: true},
		{name: "leading text", destination: "prefix{output}", wantErr: true},
		{name: "missing opening brace", destination: "output}", wantErr: true},
		{name: "missing closing brace", destination: "{output", wantErr: true},
		{name: "double closing brace", destination: "{output}}", wantErr: true},
		{name: "double opening brace", destination: "{{output}", wantErr: true},
		{name: "nested braces", destination: "{out{put}}", wantErr: true},
		{name: "empty braces", destination: "{}", wantErr: true},
		{name: "no braces", destination: "output", wantErr: true},
	} {
		t.Run(tc.name, func(t *testing.T) {
			h := Handler{
				Source:       "{http.request.uri.path}",
				Destinations: []string{tc.destination},
				Mappings: []Mapping{
					{
						Input:   "/foo",
						Outputs: []any{"FOO"},
					},
				},
			}
			err := h.Provision(caddy.Context{})
			if tc.wantErr {
				if err == nil {
					t.Fatalf("expected error for destination %q, but got none (stored %q)", tc.destination, h.Destinations[0])
				}
				return
			}
			if err != nil {
				t.Fatalf("unexpected error for destination %q: %v", tc.destination, err)
			}
			if h.Destinations[0] != tc.want {
				t.Fatalf("expected destination %q, got %q", tc.want, h.Destinations[0])
			}
		})
	}
}

func TestHandler(t *testing.T) {
	for i, tc := range []struct {
		handler Handler
		reqURI  string
		expect  map[string]any
	}{
		{
			reqURI: "/foo",
			handler: Handler{
				Source:       "{http.request.uri.path}",
				Destinations: []string{"{output}"},
				Mappings: []Mapping{
					{
						Input:   "/foo",
						Outputs: []any{"FOO"},
					},
				},
			},
			expect: map[string]any{
				"output": "FOO",
			},
		},
		{
			reqURI: "/abcdef",
			handler: Handler{
				Source:       "{http.request.uri.path}",
				Destinations: []string{"{output}"},
				Mappings: []Mapping{
					{
						InputRegexp: "(/abc)",
						Outputs:     []any{"ABC"},
					},
				},
			},
			expect: map[string]any{
				"output": "ABC",
			},
		},
		{
			reqURI: "/ABCxyzDEF",
			handler: Handler{
				Source:       "{http.request.uri.path}",
				Destinations: []string{"{output}"},
				Mappings: []Mapping{
					{
						InputRegexp: "(xyz)",
						Outputs:     []any{"...${1}..."},
					},
				},
			},
			expect: map[string]any{
				"output": "...xyz...",
			},
		},
		{
			// Test case from https://caddy.community/t/map-directive-and-regular-expressions/13866/14?u=matt
			reqURI: "/?s=0%27+AND+%28SELECT+0+FROM+%28SELECT+count%28%2A%29%2C+CONCAT%28%28SELECT+%40%40version%29%2C+0x23%2C+FLOOR%28RAND%280%29%2A2%29%29+AS+x+FROM+information_schema.columns+GROUP+BY+x%29+y%29+-+-+%27",
			handler: Handler{
				Source:       "{http.request.uri}",
				Destinations: []string{"{output}"},
				Mappings: []Mapping{
					{
						InputRegexp: "(?i)(\\^|`|<|>|%|\\\\|\\{|\\}|\\|)",
						Outputs:     []any{"3"},
					},
				},
			},
			expect: map[string]any{
				"output": "3",
			},
		},
		{
			reqURI: "/foo",
			handler: Handler{
				Source:       "{http.request.uri.path}",
				Destinations: []string{"{output}"},
				Mappings: []Mapping{
					{
						Input:   "/foo",
						Outputs: []any{"{testvar}"},
					},
				},
			},
			expect: map[string]any{
				"output": "testing",
			},
		},
		{
			reqURI: "/foo",
			handler: Handler{
				Source:       "{http.request.uri.path}",
				Destinations: []string{"{output}"},
				Defaults:     []string{"default"},
			},
			expect: map[string]any{
				"output": "default",
			},
		},
		{
			reqURI: "/foo",
			handler: Handler{
				Source:       "{http.request.uri.path}",
				Destinations: []string{"{output}"},
				Defaults:     []string{"{testvar}"},
			},
			expect: map[string]any{
				"output": "testing",
			},
		},
	} {
		if err := tc.handler.Provision(caddy.Context{}); err != nil {
			t.Fatalf("Test %d: Provisioning handler: %v", i, err)
		}

		req, err := http.NewRequest(http.MethodGet, tc.reqURI, nil)
		if err != nil {
			t.Fatalf("Test %d: Creating request: %v", i, err)
		}
		repl := caddyhttp.NewTestReplacer(req)
		repl.Set("testvar", "testing")
		ctx := context.WithValue(req.Context(), caddy.ReplacerCtxKey, repl)
		req = req.WithContext(ctx)

		rr := httptest.NewRecorder()
		noop := caddyhttp.HandlerFunc(func(_ http.ResponseWriter, _ *http.Request) error { return nil })

		if err := tc.handler.ServeHTTP(rr, req, noop); err != nil {
			t.Errorf("Test %d: Handler returned error: %v", i, err)
			continue
		}

		for key, expected := range tc.expect {
			actual, _ := repl.Get(key)
			if !reflect.DeepEqual(actual, expected) {
				t.Errorf("Test %d: Expected %#v but got %#v for {%s}", i, expected, actual, key)
			}
		}
	}
}