package bot

import (
	"encoding/json"
	"errors"
	"strings"
	"testing"

	cepis "cep.is/go"

	"cep.is/telegrambot/internal/lookup"
)

func decodeAddress(t *testing.T, body string) *cepis.Address {
	t.Helper()
	var address cepis.Address
	if err := json.Unmarshal([]byte(body), &address); err != nil {
		t.Fatalf("decode: %v", err)
	}
	return &address
}

const streetJSON = `{"cep":"01001000","logradouro":"Praça da Sé","complemento":"lado ímpar",
 "unidade":"","bairro":"Sé","localidade":"São Paulo","uf":"SP","estado":"São Paulo",
 "regiao":"Sudeste","ibge":"3550308","gia":"1004","ddd":"11","siafi":"7107",
 "geo":{"lat":-23.567202,"lon":-46.649659,"raio_m":128,"precisao":"logradouro"}}`

const municipalityJSON = `{"cep":"76200000","logradouro":"","complemento":"","unidade":"",
 "bairro":"","localidade":"Iporá","uf":"GO","estado":"Goiás","regiao":"Centro-Oeste",
 "ibge":"5210000","gia":"","ddd":"64","siafi":"9439",
 "geo":{"lat":-16.441,"lon":-51.118,"raio_m":18400,"precisao":"localidade"}}`

func TestFormatStreetLevelCEP(t *testing.T) {
	text := FormatAddress(decodeAddress(t, streetJSON))

	for _, needed := range []string{"01001-000", "Praça da Sé", "lado ímpar", "Sé — São Paulo/SP", "DDD 11", "128 m"} {
		if !strings.Contains(text, needed) {
			t.Fatalf("reply is missing %q:\n%s", needed, text)
		}
	}
	if !strings.Contains(text, "openstreetmap.org/?mlat=-23.567202&mlon=-46.649659") {
		t.Fatalf("a street-level CEP should link to the point:\n%s", text)
	}
}

func TestFormatMunicipalityCEP(t *testing.T) {
	text := FormatAddress(decodeAddress(t, municipalityJSON))

	if strings.Contains(text, "openstreetmap.org") {
		t.Fatalf("a municipality CEP must not offer a pin:\n%s", text)
	}
	for _, needed := range []string{"CEP geral de município", "centroide de Iporá", "18,4 km", "não serve", "Iporá/GO"} {
		if !strings.Contains(strings.ToLower(text), strings.ToLower(needed)) {
			t.Fatalf("reply is missing %q:\n%s", needed, text)
		}
	}
}

func TestFormatDiffersByPrecision(t *testing.T) {
	street := FormatAddress(decodeAddress(t, streetJSON))
	municipality := FormatAddress(decodeAddress(t, municipalityJSON))
	if street == municipality {
		t.Fatal("the two precisions produced the same reply")
	}
}

func TestFormatWithoutGeo(t *testing.T) {
	text := FormatAddress(decodeAddress(t, `{"cep":"29902000","logradouro":"Rua X","localidade":"Linhares","uf":"ES"}`))
	if !strings.Contains(text, "Sem coordenada") {
		t.Fatalf("reply should say there is no coordinate:\n%s", text)
	}
	if strings.Contains(text, "openstreetmap.org") {
		t.Fatalf("no coordinate must mean no link:\n%s", text)
	}
}

func TestFormatEscapesHTML(t *testing.T) {
	text := FormatAddress(decodeAddress(t, `{"cep":"12345678","logradouro":"Rua <b>Fake</b> & Cia","localidade":"X","uf":"SP"}`))
	if strings.Contains(text, "<b>Fake</b>") {
		t.Fatalf("address data must be escaped:\n%s", text)
	}
	if !strings.Contains(text, "&lt;b&gt;Fake&lt;/b&gt; &amp; Cia") {
		t.Fatalf("escaping is wrong:\n%s", text)
	}
}

func TestInlineDescriptionWarnsAboutMunicipality(t *testing.T) {
	description := InlineDescription(decodeAddress(t, municipalityJSON))
	if !strings.Contains(description, "CEP geral do município") {
		t.Fatalf("description = %q", description)
	}
	if street := InlineDescription(decodeAddress(t, streetJSON)); strings.Contains(street, "geral do município") {
		t.Fatalf("street description = %q", street)
	}
}

func TestErrorMessagesAreDistinct(t *testing.T) {
	cases := map[string]error{
		"not found":        cepis.ErrCEPNotFound,
		"invalid":          cepis.ErrInvalidCEP,
		"rate limited":     cepis.ErrRateLimited,
		"server":           cepis.ErrServer,
		"network":          cepis.ErrNetwork,
		"invalid response": cepis.ErrInvalidResponse,
		"unknown":          errors.New("something else"),
	}

	seen := make(map[string]string, len(cases))
	for name, err := range cases {
		message := ErrorMessage(err)
		if message == "" {
			t.Fatalf("%s produced no message", name)
		}
		if other, clash := seen[message]; clash {
			t.Fatalf("%s and %s share a message: %q", name, other, message)
		}
		seen[message] = name
	}
}

func notFound(faixa *lookup.Faixa) error {
	return &lookup.NotFoundError{Faixa: faixa, Err: cepis.ErrCEPNotFound}
}

var areal = &lookup.Faixa{
	Localidade: "Areal", UF: "RJ", Estado: "Rio de Janeiro", Regiao: "Sudeste",
	IBGE: "3300225", CEPIni: "25845001", CEPFim: "25849899", CEPs: 118,
}

func TestNotFoundNamesTheMunicipality(t *testing.T) {
	text := ErrorMessage(notFound(areal))

	for _, needed := range []string{
		"não encontrado", "Areal/RJ", "118 CEPs", "25845-001", "25849-899",
		"esparsa", "Confira os oito dígitos",
	} {
		if !strings.Contains(text, needed) {
			t.Fatalf("reply is missing %q:\n%s", needed, text)
		}
	}
}

// The municipality is context on a failure. A reply that looks like a hit would
// have someone write the city down as the answer.
func TestNotFoundDoesNotLookLikeAnAnswer(t *testing.T) {
	text := ErrorMessage(notFound(areal))

	if strings.Contains(text, "📮") {
		t.Fatalf("the found-address marker leaked into a failure:\n%s", text)
	}
	if !strings.HasPrefix(text, notFoundHead) {
		t.Fatalf("the reply must open by saying the CEP does not exist:\n%s", text)
	}
	if !strings.HasSuffix(text, notFoundAdvice) {
		t.Fatalf("the reply must close with the usual advice:\n%s", text)
	}
	if strings.Contains(text, "25845-000") {
		t.Fatalf("the reply suggests the CEP that just failed:\n%s", text)
	}
}

// Absence of a faixa must be indistinguishable from the day before this
// existed, byte for byte.
func TestNotFoundWithoutFaixaIsUnchanged(t *testing.T) {
	const want = "🔍 CEP não encontrado na base dos Correios (DNE).\n" +
		"Confira os oito dígitos — a base é atualizada a cada quinze dias."

	for name, err := range map[string]error{
		"plain sentinel": cepis.ErrCEPNotFound,
		"no faixa":       notFound(nil),
		"empty faixa":    notFound(&lookup.Faixa{}),
	} {
		if got := ErrorMessage(err); got != want {
			t.Fatalf("%s:\n got %q\nwant %q", name, got, want)
		}
	}
}

func TestNotFoundEscapesTheMunicipality(t *testing.T) {
	text := ErrorMessage(notFound(&lookup.Faixa{
		Localidade: "Santa <b>Rita</b> & Cia", UF: "M&G",
		CEPIni: "25845001", CEPFim: "25849899", CEPs: 2,
	}))

	if strings.Contains(text, "<b>Rita</b>") {
		t.Fatalf("the municipality name must be escaped:\n%s", text)
	}
	if !strings.Contains(text, "Santa &lt;b&gt;Rita&lt;/b&gt; &amp; Cia/M&amp;G") {
		t.Fatalf("escaping is wrong:\n%s", text)
	}
}

// Every field of the faixa is optional in practice, and a missing one may not
// take the sentence down with it.
func TestNotFoundDegradesFieldByField(t *testing.T) {
	cases := map[string]struct {
		faixa   *lookup.Faixa
		present []string
		absent  []string
	}{
		"no count": {
			faixa:   &lookup.Faixa{Localidade: "Areal", UF: "RJ", CEPIni: "25845001", CEPFim: "25849899"},
			present: []string{"Areal/RJ", "25845-001", "25849-899", "esparsa"},
			absent:  []string{"CEPs,"},
		},
		"no range": {
			faixa:   &lookup.Faixa{Localidade: "Areal", UF: "RJ", CEPs: 118},
			present: []string{"Areal/RJ", "118 CEPs"},
			absent:  []string{"<code>", "esparsa"},
		},
		"only the name": {
			faixa:   &lookup.Faixa{Localidade: "Areal"},
			present: []string{"cairia em <b>Areal</b>."},
			absent:  []string{"<code>", "esparsa", "Areal/"},
		},
		"single CEP": {
			faixa:   &lookup.Faixa{Localidade: "Vila", UF: "SP", CEPIni: "12345678", CEPFim: "12345678", CEPs: 1},
			present: []string{"1 CEP."},
			absent:  []string{"12345-678"},
		},
		"unusable range": {
			faixa:   &lookup.Faixa{Localidade: "Areal", UF: "RJ", CEPIni: "abc", CEPFim: "2584", CEPs: 118},
			present: []string{"118 CEPs."},
			absent:  []string{"abc", "2584"},
		},
	}

	for name, tc := range cases {
		t.Run(name, func(t *testing.T) {
			text := ErrorMessage(notFound(tc.faixa))
			for _, needed := range tc.present {
				if !strings.Contains(text, needed) {
					t.Fatalf("missing %q:\n%s", needed, text)
				}
			}
			for _, unwanted := range tc.absent {
				if strings.Contains(text, unwanted) {
					t.Fatalf("should not carry %q:\n%s", unwanted, text)
				}
			}
		})
	}
}

func TestInlineErrorDescriptionNamesTheMunicipality(t *testing.T) {
	if got := inlineErrorDescription(notFound(areal)); got != "Cairia em Areal/RJ — toque para ver" {
		t.Fatalf("description = %q", got)
	}
	if got := inlineErrorDescription(cepis.ErrCEPNotFound); got != "Toque para enviar o motivo" {
		t.Fatalf("description without a faixa = %q", got)
	}
	// Titles and descriptions are plain text: escaping them would show the
	// entities to the user.
	got := inlineErrorDescription(notFound(&lookup.Faixa{Localidade: "Santa & Cia", UF: "SP"}))
	if !strings.Contains(got, "Santa & Cia/SP") {
		t.Fatalf("description = %q", got)
	}
}

func TestHelpMentionsEveryEntryPoint(t *testing.T) {
	text := HelpMessage("cepisbot")
	for _, needed := range []string{"01001-000", "/cep 01001000", "@cepisbot 01001000", "https://cep.is"} {
		if !strings.Contains(text, needed) {
			t.Fatalf("help is missing %q:\n%s", needed, text)
		}
	}
}