package server

import (
	"bytes"
	"context"
	"encoding/json"
	"io"
	"log/slog"
	"net/http"
	"net/http/cookiejar"
	"net/http/httptest"
	"path/filepath"
	"strings"
	"testing"
	"time"

	"jarl/internal/api"
	"jarl/internal/auth"
	"jarl/internal/engine"
	"jarl/internal/model"
	"jarl/internal/render"
	"jarl/internal/stats"
	"jarl/internal/store"
)

type apiEnv struct {
	t     *testing.T
	ts    *httptest.Server
	st    *store.Store
	token string // admin token
}

// newAPIEnv starts an API server; a statistics collector may be given.
func newAPIEnv(t *testing.T, collector ...*stats.Collector) *apiEnv {
	t.Helper()
	dir := t.TempDir()
	st, err := store.Open(filepath.Join(dir, "jarl.db"))
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { st.Close() })
	quiet := slog.New(slog.NewTextHandler(io.Discard, nil))
	eng := engine.New(st, nil, engine.Config{
		Paths:      render.Paths{ConfigDir: filepath.Join(dir, "etc"), ZoneDir: filepath.Join(dir, "zones"), CacheDir: filepath.Join(dir, "cache")},
		StagingDir: filepath.Join(dir, "staging"), NoReload: true, SkipCheck: true,
	}, quiet)
	cfg := Config{Version: "test"}
	if len(collector) > 0 {
		cfg.Stats = collector[0]
	}
	srv := New(cfg, eng, quiet, nil)
	ts := httptest.NewServer(srv.Handler())
	t.Cleanup(ts.Close)
	hash, _ := auth.HashPassword("correct horse battery")
	admin := &model.User{Username: "admin", PasswordHash: hash, Admin: true}
	st.CreateUser(context.Background(), admin)
	tok, pid, sh := auth.NewToken()
	st.CreateToken(context.Background(), &model.Token{UserID: admin.ID, Name: "test", PublicID: pid, SecretHash: sh})
	env := &apiEnv{t: t, ts: ts, st: st, token: tok}
	env.do("PATCH", "/settings", env.token, map[string]any{"nameservers": []string{"ns1.example.com."}}, 200)
	return env
}

// do sends a request with a bearer token and checks the status.
func (e *apiEnv) do(method, path, token string, body any, want int) map[string]any {
	e.t.Helper()
	out, status := e.req(method, path, token, body)
	if status != want {
		e.t.Fatalf("%s %s = %d, want %d: %s", method, path, status, want, out)
	}
	if len(out) == 0 {
		return nil
	}
	var m map[string]any
	if json.Unmarshal(out, &m) != nil {
		return map[string]any{"_raw": string(out)}
	}
	return m
}

func (e *apiEnv) req(method, path, token string, body any) ([]byte, int) {
	var rd io.Reader
	if body != nil {
		b, _ := json.Marshal(body)
		rd = bytes.NewReader(b)
	}
	r, _ := http.NewRequest(method, e.ts.URL+api.Prefix+path, rd)
	if token != "" {
		r.Header.Set("Authorization", "Bearer "+token)
	}
	r.Header.Set("Content-Type", "application/json")
	resp, err := http.DefaultClient.Do(r)
	if err != nil {
		e.t.Fatal(err)
	}
	defer resp.Body.Close()
	b, _ := io.ReadAll(resp.Body)
	return b, resp.StatusCode
}

func (e *apiEnv) list(path, token string) []map[string]any {
	e.t.Helper()
	b, status := e.req("GET", path, token, nil)
	if status != 200 {
		e.t.Fatalf("GET %s = %d: %s", path, status, b)
	}
	var out []map[string]any
	json.Unmarshal(b, &out)
	return out
}

func TestRecordsAPI(t *testing.T) {
	e := newAPIEnv(t)
	e.do("POST", "/zones", e.token, map[string]any{"name": "example.com", "records": []map[string]any{{"name": "ns1", "type": "A", "data": "192.0.2.1"}}}, 201)
	res := e.do("POST", "/zones/example.com/records", e.token, map[string]any{"name": "www", "type": "A", "data": "192.0.2.10", "ttl": 300}, 201)
	obj := res["object"].(map[string]any)
	if obj["name"] != "www.example.com." || obj["relative_name"] != "www" || obj["effective_ttl"].(float64) != 300 {
		t.Errorf("object = %v", obj)
	}
	id := int64(obj["id"].(float64))
	// The CNAME rule, over HTTP.
	b, status := e.req("POST", "/zones/example.com/records", e.token, map[string]any{"name": "www", "type": "CNAME", "data": "ns1"})
	if status != 422 || !strings.Contains(string(b), "cname_conflict") {
		t.Errorf("CNAME next to A: %d %s", status, b)
	}
	// Bad data is a 400 with a clear message.
	b, status = e.req("POST", "/zones/example.com/records", e.token, map[string]any{"name": "x", "type": "A", "data": "1.2.3"})
	if status != 400 || !strings.Contains(string(b), "invalid A data") {
		t.Errorf("bad data: %d %s", status, b)
	}
	// TXT as plain text.
	e.do("POST", "/zones/example.com/records", e.token, map[string]any{"name": "@", "type": "TXT", "data": "v=spf1 mx -all"}, 201)
	recs := e.list("/zones/example.com/records?type=TXT", e.token)
	if len(recs) != 1 || recs[0]["data"] != `"v=spf1 mx -all"` || recs[0]["text"] != "v=spf1 mx -all" {
		t.Errorf("TXT = %v", recs)
	}
	// Update, dry run first.
	res = e.do("PATCH", "/records/"+itoa(id)+"?dry_run=1", e.token, map[string]any{"data": "192.0.2.11"}, 200)
	if res["applied"] == true || !strings.Contains(res["result"].(map[string]any)["diff"].(string), "192.0.2.11") {
		t.Errorf("dry run = %v", res)
	}
	e.do("PATCH", "/records/"+itoa(id), e.token, map[string]any{"data": "192.0.2.11"}, 200)
	got := e.do("GET", "/records/"+itoa(id), e.token, nil, 200)
	if got["data"] != "192.0.2.11" {
		t.Errorf("after update = %v", got)
	}
	// RRset replace and delete by match.
	e.do("PUT", "/zones/example.com/rrsets/api/A", e.token, map[string]any{"ttl": 60, "data": []string{"192.0.2.30", "192.0.2.31"}}, 200)
	if n := len(e.list("/zones/example.com/records?name=api", e.token)); n != 2 {
		t.Errorf("rrset has %d records", n)
	}
	e.do("DELETE", "/zones/example.com/records?name=api&type=A&data=192.0.2.30", e.token, nil, 200)
	e.do("DELETE", "/zones/example.com/rrsets/api/A", e.token, nil, 200)
	if n := len(e.list("/zones/example.com/records?name=api", e.token)); n != 0 {
		t.Errorf("rrset not deleted: %d", n)
	}
	// Zone file.
	b, status = e.req("GET", "/zones/example.com/file", e.token, nil)
	if status != 200 || !strings.Contains(string(b), "www\t\tIN\tA\t192.0.2.11") && !strings.Contains(string(b), "www\t300\tIN\tA\t192.0.2.11") {
		t.Errorf("zone file %d:\n%s", status, b)
	}
	// History and revert.
	cs := e.list("/changesets?status=applied", e.token)
	if len(cs) < 5 {
		t.Errorf("changesets = %d", len(cs))
	}
	if strings.Contains(string(mustJSON(cs)), `"undo"`) {
		t.Error("undo ops leaked in changeset list")
	}
}

func itoa(n int64) string { return strings.TrimSpace(strings.TrimSuffix(string(mustJSON(n)), "\n")) }

func mustJSON(v any) []byte {
	b, _ := json.Marshal(v)
	return b
}

func TestStagingAPI(t *testing.T) {
	e := newAPIEnv(t)
	e.do("POST", "/zones", e.token, map[string]any{"name": "example.com", "records": []map[string]any{{"name": "ns1", "type": "A", "data": "192.0.2.1"}}}, 201)
	cs := e.do("POST", "/changesets", e.token, map[string]any{"description": "web refresh"}, 201)
	id := itoa(int64(cs["id"].(float64)))
	res := e.do("POST", "/zones/example.com/records?changeset="+id, e.token, map[string]any{"name": "www", "type": "A", "data": "192.0.2.10"}, 202)
	if res["staged"] != true {
		t.Errorf("not staged: %v", res)
	}
	if n := len(e.list("/zones/example.com/records?name=www", e.token)); n != 0 {
		t.Error("staged record visible before apply")
	}
	prev := e.do("GET", "/changesets/"+id+"/preview", e.token, nil, 200)
	if prev["valid"] != true || !strings.Contains(prev["diff"].(string), "192.0.2.10") {
		t.Errorf("preview = %v", prev)
	}
	e.do("POST", "/changesets/"+id+"/apply", e.token, nil, 200)
	if n := len(e.list("/zones/example.com/records?name=www", e.token)); n != 1 {
		t.Error("record missing after apply")
	}
	b, status := e.req("POST", "/zones/example.com/records?changeset="+id, e.token, map[string]any{"name": "x", "type": "A", "data": "192.0.2.2"})
	if status != 409 {
		t.Errorf("staging into applied changeset: %d %s", status, b)
	}
	// Batch apply is atomic.
	b, status = e.req("POST", "/apply", e.token, map[string]any{"ops": []map[string]any{
		{"op": "record.create", "data": map[string]any{"zone": "example.com", "name": "a", "type": "A", "data": "192.0.2.3"}},
		{"op": "record.create", "data": map[string]any{"zone": "example.com", "name": "a", "type": "CNAME", "data": "www"}},
	}})
	if status != 422 {
		t.Errorf("bad batch: %d %s", status, b)
	}
	if n := len(e.list("/zones/example.com/records?name=a", e.token)); n != 0 {
		t.Error("part of a failed batch was applied")
	}
}

func TestSessionsAndPermissions(t *testing.T) {
	e := newAPIEnv(t)
	e.do("POST", "/zones", e.token, map[string]any{"name": "example.com", "records": []map[string]any{{"name": "ns1", "type": "A", "data": "192.0.2.1"}}}, 201)
	e.do("POST", "/zones", e.token, map[string]any{"name": "secret.org", "nameservers": []string{"ns1.example.com."}}, 201)
	// Unauthenticated.
	if _, status := e.req("GET", "/zones", "", nil); status != 401 {
		t.Errorf("unauthenticated = %d", status)
	}
	if _, status := e.req("GET", "/zones", "jarl_aaaaaaaaaaaaaaaa_bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb", nil); status != 401 {
		t.Errorf("bad token = %d", status)
	}
	// An ACME user with a restricted token.
	e.do("POST", "/users", e.token, map[string]any{"username": "acme", "password": "acme-password-123", "grant_strings": []string{"records:write zones=example.com names=_acme-challenge.* types=TXT"}}, 201)
	users := e.list("/users", e.token)
	var acmeID int64
	for _, u := range users {
		if u["username"] == "acme" {
			acmeID = int64(u["id"].(float64))
		}
	}
	tok := e.do("POST", "/users/"+itoa(acmeID)+"/tokens", e.token, map[string]any{"name": "certbot", "expires_in": "90d"}, 201)
	acme := tok["token"].(string)
	e.do("POST", "/zones/example.com/records", acme, map[string]any{"name": "_acme-challenge.www", "type": "TXT", "data": "token"}, 201)
	if _, status := e.req("POST", "/zones/example.com/records", acme, map[string]any{"name": "www", "type": "A", "data": "192.0.2.66"}); status != 403 {
		t.Errorf("acme wrote an A record: %d", status)
	}
	zones := e.list("/zones", acme)
	if len(zones) != 1 || zones[0]["name"] != "example.com." {
		t.Errorf("acme sees zones %v", zones)
	}
	if recs := e.list("/zones/example.com/records", acme); len(recs) != 1 {
		t.Errorf("acme sees %d records", len(recs))
	}
	if _, status := e.req("GET", "/zones/secret.org", acme, nil); status != 404 {
		t.Errorf("acme can see secret.org: %d", status)
	}
	if _, status := e.req("GET", "/users", acme, nil); status != 403 {
		t.Errorf("acme lists users: %d", status)
	}
	// Session login with CSRF protection.
	jar, _ := cookiejar.New(nil)
	c := &http.Client{Jar: jar}
	post := func(path, csrf string, body any) *http.Response {
		b, _ := json.Marshal(body)
		r, _ := http.NewRequest("POST", e.ts.URL+api.Prefix+path, bytes.NewReader(b))
		r.Header.Set("Content-Type", "application/json")
		if csrf != "" {
			r.Header.Set(csrfHeader, csrf)
		}
		resp, err := c.Do(r)
		if err != nil {
			t.Fatal(err)
		}
		return resp
	}
	resp := post("/auth/login", "", map[string]string{"username": "admin", "password": "wrong"})
	if resp.StatusCode != 401 {
		t.Errorf("wrong password = %d", resp.StatusCode)
	}
	resp = post("/auth/login", "", map[string]string{"username": "ADMIN", "password": "correct horse battery"})
	var who api.Whoami
	json.NewDecoder(resp.Body).Decode(&who)
	resp.Body.Close()
	if resp.StatusCode != 200 || who.CSRFToken == "" || !who.Admin {
		t.Fatalf("login = %d %+v", resp.StatusCode, who)
	}
	if r := post("/zones/example.com/records", "", map[string]any{"name": "web", "type": "A", "data": "192.0.2.80"}); r.StatusCode != 403 {
		t.Errorf("missing CSRF = %d", r.StatusCode)
	}
	if r := post("/zones/example.com/records", who.CSRFToken, map[string]any{"name": "web", "type": "A", "data": "192.0.2.80"}); r.StatusCode != 201 {
		b, _ := io.ReadAll(r.Body)
		t.Errorf("with CSRF = %d %s", r.StatusCode, b)
	}
	cs := e.list("/changesets?status=applied", e.token)
	if cs[0]["via"] != "web" || cs[0]["username"] != "admin" {
		t.Errorf("last changeset = %v", cs[0])
	}
	if r := post("/auth/logout", who.CSRFToken, nil); r.StatusCode != 204 {
		t.Errorf("logout = %d", r.StatusCode)
	}
	resp2, _ := c.Get(e.ts.URL + api.Prefix + "/auth/whoami")
	if resp2.StatusCode != 401 {
		t.Errorf("after logout = %d", resp2.StatusCode)
	}
	// Audit trail.
	evs := e.list("/audit?action=auth.", e.token)
	if len(evs) < 3 {
		t.Errorf("auth audit events = %d", len(evs))
	}
	// Login rate limiting.
	for i := 0; i < 10; i++ {
		post("/auth/login", "", map[string]string{"username": "acme", "password": "nope"})
	}
	if r := post("/auth/login", "", map[string]string{"username": "acme", "password": "acme-password-123"}); r.StatusCode != 429 {
		t.Errorf("rate limit = %d", r.StatusCode)
	}
}

func TestTSIGSecrets(t *testing.T) {
	e := newAPIEnv(t)
	res := e.do("POST", "/tsig-keys", e.token, map[string]any{"name": "xfer"}, 201)
	obj := res["object"].(map[string]any)
	if s, _ := obj["secret"].(string); len(s) != 44 {
		t.Errorf("generated secret not returned once: %v", obj)
	}
	list := e.list("/tsig-keys", e.token)
	if _, has := list[0]["secret"]; has {
		t.Error("secret in list")
	}
	k := e.do("GET", "/tsig-keys/xfer?secret=1", e.token, nil, 200)
	if len(k["secret"].(string)) != 44 {
		t.Error("secret not revealed")
	}
	ops := e.list("/changesets?status=applied", e.token)[0]["ops"].([]any)
	if !strings.Contains(string(mustJSON(ops)), "(hidden)") {
		t.Errorf("secret not redacted in changeset: %s", mustJSON(ops))
	}
	_ = time.Now
}