package api_test

import (
	"bytes"
	"crypto/sha256"
	"encoding/hex"
	"encoding/json"
	"io"
	"net/http"
	"net/http/cookiejar"
	"strings"
	"testing"

	"halcyon/api"
)

const adminPW = "correct horse battery"

// admin is a browser-like client (it keeps the session cookie) for the admin API.
type admin struct {
	t    *testing.T
	base string
	c    *http.Client
}

func newAdmin(t *testing.T, base string) *admin {
	jar, _ := cookiejar.New(nil)
	return &admin{t: t, base: base, c: &http.Client{Jar: jar}}
}

func (a *admin) req(method, path string, body any, headers map[string]string) (*http.Response, []byte) {
	a.t.Helper()
	var rdr io.Reader
	if body != nil {
		b, _ := json.Marshal(body)
		rdr = bytes.NewReader(b)
	}
	req, _ := http.NewRequest(method, a.base+path, rdr)
	for k, v := range headers {
		req.Header.Set(k, v)
	}
	resp, err := a.c.Do(req)
	if err != nil {
		a.t.Fatal(err)
	}
	defer resp.Body.Close()
	b, _ := io.ReadAll(resp.Body)
	return resp, b
}

func (a *admin) get(path string, want int) []byte {
	a.t.Helper()
	resp, b := a.req("GET", path, nil, nil)
	if resp.StatusCode != want {
		a.t.Fatalf("GET %s: status %d want %d: %s", path, resp.StatusCode, want, b)
	}
	return b
}

func (a *admin) login() { a.t.Helper(); a.mustLogin(adminPW) }

func (a *admin) mustLogin(pw string) {
	a.t.Helper()
	resp, b := a.req("POST", "/admin/api/login", map[string]string{"password": pw}, nil)
	if resp.StatusCode != 200 {
		a.t.Fatalf("admin login: %d %s", resp.StatusCode, b)
	}
}

type auditRow struct {
	ID       int64          `json:"id"`
	At       int64          `json:"at"`
	PlayerID int64          `json:"player_id"`
	Name     string         `json:"name"`
	Action   string         `json:"action"`
	Ship     int64          `json:"ship"`
	Slot     int            `json:"slot"`
	Detail   map[string]any `json:"detail"`
	IP       string         `json:"ip"`
}

func (a *admin) audit(query string) []auditRow {
	a.t.Helper()
	var rows []auditRow
	if err := json.Unmarshal(a.get("/admin/api/audit"+query, 200), &rows); err != nil {
		a.t.Fatal(err)
	}
	return rows
}

func actionsOf(rows []auditRow) []string {
	var out []string
	for i := len(rows) - 1; i >= 0; i-- { // oldest first
		out = append(out, rows[i].Action)
	}
	return out
}

func TestAdminIsOffWithoutAPassword(t *testing.T) {
	srv, _ := newSite(t, "")
	a := newAdmin(t, srv.URL)
	resp, b := a.req("POST", "/admin/api/login", map[string]string{"password": ""}, nil)
	if resp.StatusCode != 404 || !strings.Contains(string(b), "HALCYON_ADMIN_PASSWORD") {
		t.Fatalf("login with the interface off: %d %s", resp.StatusCode, b)
	}
	a.get("/admin/api/accounts", 404)
	a.get("/admin/api/audit", 404)
}

func TestAdminLoginAndSession(t *testing.T) {
	srv, _ := newSite(t, "", api.WithAdminPassword(adminPW))
	a := newAdmin(t, srv.URL)

	a.get("/admin/api/session", 401)
	a.get("/admin/api/accounts", 401)
	a.get("/admin/api/audit", 401)

	if resp, _ := a.req("POST", "/admin/api/login", map[string]string{"password": "wrong"}, nil); resp.StatusCode != 401 {
		t.Fatalf("wrong password: %d", resp.StatusCode)
	}
	if resp, _ := a.req("POST", "/admin/api/login", "not json", nil); resp.StatusCode != 400 {
		t.Fatalf("malformed body: %d", resp.StatusCode)
	}
	a.get("/admin/api/session", 401) // failed attempts do not log anyone in

	resp, _ := a.req("POST", "/admin/api/login", map[string]string{"password": adminPW}, nil)
	if resp.StatusCode != 200 {
		t.Fatalf("login: %d", resp.StatusCode)
	}
	var cookie *http.Cookie
	for _, c := range resp.Cookies() {
		if c.Name == "halcyon_admin" {
			cookie = c
		}
	}
	if cookie == nil || !cookie.HttpOnly || cookie.SameSite != http.SameSiteStrictMode || cookie.Path != "/admin" || cookie.MaxAge <= 0 {
		t.Fatalf("session cookie = %+v: it must be HttpOnly, SameSite=Strict, scoped to /admin and expire", cookie)
	}
	if cookie.Secure {
		t.Error("a plain-HTTP request should not get a Secure cookie (the browser would drop it)")
	}
	a.get("/admin/api/session", 200)
	a.get("/admin/api/accounts", 200)

	// Behind the TLS-terminating proxy the cookie is Secure.
	b := newAdmin(t, srv.URL)
	resp, _ = b.req("POST", "/admin/api/login", map[string]string{"password": adminPW}, map[string]string{"X-Forwarded-Proto": "https"})
	if c := resp.Cookies(); len(c) == 0 || !c[0].Secure {
		t.Errorf("cookie behind https = %+v, want Secure", c)
	}

	// Every admin response is uncacheable.
	if resp, _ := a.req("GET", "/admin/api/accounts", nil, nil); resp.Header.Get("Cache-Control") != "no-store" {
		t.Errorf("Cache-Control = %q", resp.Header.Get("Cache-Control"))
	}

	// A tampered cookie is refused.
	tampered := newAdmin(t, srv.URL)
	req, _ := http.NewRequest("GET", srv.URL+"/admin/api/accounts", nil)
	req.AddCookie(&http.Cookie{Name: "halcyon_admin", Value: "9999999999." + strings.Repeat("a", 64)})
	if resp, err := tampered.c.Do(req); err != nil || resp.StatusCode != 401 {
		t.Fatalf("forged cookie: %v %v", resp, err)
	}

	// Logout ends the session.
	if resp, _ := a.req("POST", "/admin/api/logout", nil, nil); resp.StatusCode != 204 {
		t.Fatalf("logout: %d", resp.StatusCode)
	}
	a.get("/admin/api/session", 401)
}

func TestAdminLoginIsRateLimitedPerAddress(t *testing.T) {
	srv, _ := newSite(t, "", api.WithAdminPassword(adminPW))
	a := newAdmin(t, srv.URL)
	// Behind the proxy the client's address is X-Forwarded-For; the test server's own peer is loopback.
	from := func(ip string) map[string]string { return map[string]string{"X-Forwarded-For": ip} }
	for i := 0; i < 5; i++ {
		if resp, _ := a.req("POST", "/admin/api/login", map[string]string{"password": "guess"}, from("203.0.113.9")); resp.StatusCode != 401 {
			t.Fatalf("attempt %d: %d", i+1, resp.StatusCode)
		}
	}
	// Now even the right password is refused for that address...
	resp, _ := a.req("POST", "/admin/api/login", map[string]string{"password": adminPW}, from("203.0.113.9"))
	if resp.StatusCode != 429 || resp.Header.Get("Retry-After") == "" {
		t.Fatalf("locked out address: %d retry-after=%q", resp.StatusCode, resp.Header.Get("Retry-After"))
	}
	// ...but not for anyone else.
	if resp, _ := a.req("POST", "/admin/api/login", map[string]string{"password": adminPW}, from("198.51.100.7")); resp.StatusCode != 200 {
		t.Fatalf("a different address was locked out too: %d", resp.StatusCode)
	}
}

func TestAdminAndPlayerCredentialsAreSeparate(t *testing.T) {
	srv, _ := newSite(t, "", api.WithAdminPassword(adminPW))
	p := newPlayer(t, srv.URL, "ann")
	a := newAdmin(t, srv.URL)
	a.login()

	// A player's API key opens nothing under /admin, and the admin session opens nothing of a player's.
	resp, _ := http.DefaultClient.Do(mustReq("GET", srv.URL+"/admin/api/accounts", "Bearer "+p.key))
	if resp.StatusCode != 401 {
		t.Fatalf("a player key on the admin API: %d", resp.StatusCode)
	}
	if resp, _ := a.req("GET", "/ships", nil, nil); resp.StatusCode != 401 {
		t.Fatalf("the admin cookie on a player endpoint: %d", resp.StatusCode)
	}
	// The admin password is not an API key.
	resp, _ = http.DefaultClient.Do(mustReq("GET", srv.URL+"/me", "Bearer "+adminPW))
	if resp.StatusCode != 401 {
		t.Fatalf("the admin password as an API key: %d", resp.StatusCode)
	}
}

func mustReq(method, url, auth string) *http.Request {
	r, _ := http.NewRequest(method, url, nil)
	r.Header.Set("Authorization", auth)
	return r
}

func TestAuditTrailOfPlayerActions(t *testing.T) {
	srv, cfg := newSite(t, "", api.WithAdminPassword(adminPW))
	a := newAdmin(t, srv.URL)
	a.login()
	if rows := a.audit(""); len(rows) != 0 {
		t.Fatalf("a new world has %d audit entries", len(rows))
	}

	p := newPlayer(t, srv.URL, "ann") // register
	post := func(path string, body any, want int, hdr map[string]string) {
		t.Helper()
		var rdr io.Reader
		if body != nil {
			b, _ := json.Marshal(body)
			rdr = bytes.NewReader(b)
		}
		req, _ := http.NewRequest("POST", srv.URL+path, rdr)
		req.Header.Set("Authorization", "Bearer "+p.key)
		for k, v := range hdr {
			req.Header.Set(k, v)
		}
		resp, err := http.DefaultClient.Do(req)
		if err != nil {
			t.Fatal(err)
		}
		resp.Body.Close()
		if resp.StatusCode != want {
			t.Fatalf("POST %s: %d, want %d", path, resp.StatusCode, want)
		}
	}
	post("/login", nil, 200, map[string]string{"User-Agent": "TestBrowser/1.0", "X-Forwarded-For": "203.0.113.55, 10.0.0.1"})
	src := "ldi r1, 5\nhalt"
	p.do("PUT", "/slots/5", map[string]string{"name": "MINER", "source": src}, 200)
	p.do("PUT", "/slots/5", map[string]string{"name": "MINER 2", "source": "halt"}, 200)
	p.do("DELETE", "/slots/5", nil, 204)
	p.do("PUT", "/slots/6", map[string]string{"name": "TINY", "source": src}, 200)
	post("/ships/"+itoa(p.ship)+"/launch", map[string]int{"slot": 6}, 202, nil)
	msg := []byte{0x48, 0x45, 0x4c, 0x4c, 0x4f, 0x00, 0xff}
	req, _ := http.NewRequest("PUT", srv.URL+"/ships/"+itoa(p.ship)+"/uplink", bytes.NewReader(msg))
	req.Header.Set("Authorization", "Bearer "+p.key)
	if resp, err := http.DefaultClient.Do(req); err != nil || resp.StatusCode != 204 {
		t.Fatalf("uplink: %v %v", resp, err)
	}

	rows := a.audit("")
	want := []string{"register", "login", "code_save", "code_save", "code_clear", "code_save", "launch", "uplink"}
	if got := actionsOf(rows); strings.Join(got, ",") != strings.Join(want, ",") {
		t.Fatalf("audit trail = %v\nwant       %v", got, want)
	}
	if rows[0].Action != "uplink" || rows[len(rows)-1].Action != "register" {
		t.Fatal("entries should be listed newest first")
	}
	byAction := map[string][]auditRow{}
	for i := len(rows) - 1; i >= 0; i-- {
		byAction[rows[i].Action] = append(byAction[rows[i].Action], rows[i])
	}
	for _, r := range rows {
		if r.Name != "ann" || r.PlayerID != 1 || r.At == 0 || r.IP == "" {
			t.Errorf("entry %d lacks who/when/where: %+v", r.ID, r)
		}
	}
	if d := byAction["register"][0].Detail; d["name"] != "ann" || byAction["register"][0].Ship != p.ship {
		t.Errorf("register: %+v", byAction["register"][0])
	}
	lg := byAction["login"][0]
	if lg.IP != "203.0.113.55" || lg.Detail["user_agent"] != "TestBrowser/1.0" {
		t.Errorf("login: ip=%q detail=%v (the client address behind the proxy, and its browser)", lg.IP, lg.Detail)
	}
	s1 := byAction["code_save"][0]
	if s1.Slot != 5 || s1.Detail["name"] != "MINER" || s1.Detail["bytes"] != float64(len(src)) || s1.Detail["sha256"] != sha256hex(src) {
		t.Errorf("first save: %+v", s1)
	}
	if s2 := byAction["code_save"][1]; s2.Slot != 5 || s2.Detail["name"] != "MINER 2" {
		t.Errorf("second save: %+v", s2)
	}
	if c := byAction["code_clear"][0]; c.Slot != 5 {
		t.Errorf("clear: %+v", c)
	}
	l := byAction["launch"][0]
	if l.Ship != p.ship || l.Slot != 6 || l.Detail["program_bytes"] != float64(8) || l.Detail["slot_name"] != "TINY" {
		t.Errorf("launch: %+v", l)
	}
	u := byAction["uplink"][0]
	if u.Ship != p.ship || u.Detail["bytes"] != float64(len(msg)) || u.Detail["hex"] != hex.EncodeToString(msg) {
		t.Errorf("uplink: %+v (the data itself must be recorded)", u)
	}

	// Filters and paging.
	if got := actionsOf(a.audit("?action=code_save")); len(got) != 3 {
		t.Errorf("action filter returned %v", got)
	}
	if got := a.audit("?action=CODE_SAVE"); len(got) != 3 {
		t.Errorf("action filters ignore case: got %d", len(got))
	}
	if got := a.audit("?player=1"); len(got) != len(want) {
		t.Errorf("player filter: %d", len(got))
	}
	if got := a.audit("?player=99"); len(got) != 0 {
		t.Errorf("unknown player: %d entries", len(got))
	}
	var seen []int64
	before := ""
	for i := 0; i < 10; i++ {
		page := a.audit("?limit=3" + before)
		if len(page) == 0 {
			break
		}
		for _, r := range page {
			seen = append(seen, r.ID)
		}
		before = "&before=" + itoa(page[len(page)-1].ID)
	}
	if len(seen) != len(want) {
		t.Fatalf("paging returned %d entries %v, want %d", len(seen), seen, len(want))
	}
	for i := 1; i < len(seen); i++ {
		if seen[i] >= seen[i-1] {
			t.Fatalf("paging repeated or reordered entries: %v", seen)
		}
	}
	for _, q := range []string{"?action=bogus", "?player=abc", "?before=-1", "?limit=0", "?limit=x"} {
		a.get("/admin/api/audit"+q, 400)
	}

	// Things that failed are not actions taken, and are not logged.
	n := len(a.audit(""))
	p.do("PUT", "/slots/1", map[string]string{"name": "X", "source": "halt"}, 403)                // read-only example
	p.do("POST", "/ships/"+itoa(p.ship)+"/launch", map[string]int{"slot": 6}, 409)                // already launching
	p.do("PUT", "/ships/"+itoa(p.ship)+"/program", string(make([]byte, cfg.ProgramBytes+4)), 413) // too large
	bad := &player{t: t, base: srv.URL, key: "not-a-key"}
	bad.do("POST", "/login", nil, 401) // a wrong key is not a login
	if got := len(a.audit("")); got != n {
		t.Errorf("%d entries recorded for actions that failed", got-n)
	}
}

func TestAuditRecordsProgramUploadAndPlainLaunch(t *testing.T) {
	srv, _ := newSite(t, "", api.WithAdminPassword(adminPW))
	a := newAdmin(t, srv.URL)
	a.login()
	p := newPlayer(t, srv.URL, "bob")
	prog := []byte{0x02, 0, 0, 0} // HALT
	req, _ := http.NewRequest("PUT", srv.URL+"/ships/"+itoa(p.ship)+"/program", bytes.NewReader(prog))
	req.Header.Set("Authorization", "Bearer "+p.key)
	if resp, err := http.DefaultClient.Do(req); err != nil || resp.StatusCode != 204 {
		t.Fatalf("upload: %v %v", resp, err)
	}
	p.do("POST", "/ships/"+itoa(p.ship)+"/launch", nil, 202)
	rows := a.audit("")
	if got := strings.Join(actionsOf(rows), ","); got != "register,program_upload,launch" {
		t.Fatalf("trail = %s", got)
	}
	if up := rows[1]; up.Detail["bytes"] != float64(4) || up.Detail["sha256"] != sha256hex(string(prog)) || up.Ship != p.ship {
		t.Errorf("program upload: %+v", up)
	}
	if l := rows[0]; l.Slot != 0 || l.Ship != p.ship || l.Detail["program"] == nil {
		t.Errorf("plain launch: %+v", l)
	}
}

func TestAdminAccountsAndDetail(t *testing.T) {
	srv, _ := newSite(t, "", api.WithAdminPassword(adminPW))
	a := newAdmin(t, srv.URL)
	a.login()

	ann := newPlayer(t, srv.URL, "ann")
	bob := newPlayer(t, srv.URL, "<img src=x onerror=alert(1)>") // hostile names must come back as plain data
	req, _ := http.NewRequest("POST", srv.URL+"/login", nil)
	req.Header.Set("Authorization", "Bearer "+ann.key)
	if resp, err := http.DefaultClient.Do(req); err != nil || resp.StatusCode != 200 {
		t.Fatalf("login: %v %v", resp, err)
	}
	ann.do("PUT", "/slots/4", map[string]string{"name": "ALPHA", "source": "; alpha\nhalt"}, 200)
	ann.do("PUT", "/slots/9", map[string]string{"name": "OMEGA", "source": "; omega\nhalt"}, 200)
	ann.do("POST", "/ships/"+itoa(ann.ship)+"/launch", map[string]int{"slot": 4}, 202)

	var accts []struct {
		ID         int64  `json:"id"`
		Name       string `json:"name"`
		Credits    int64  `json:"credits"`
		Ships      int    `json:"ships"`
		SlotsUsed  int    `json:"slots_used"`
		Actions    int    `json:"actions"`
		LastLogin  int64  `json:"last_login"`
		LastAction int64  `json:"last_action"`
	}
	if err := json.Unmarshal(a.get("/admin/api/accounts", 200), &accts); err != nil || len(accts) != 2 {
		t.Fatalf("accounts: %v %v", err, accts)
	}
	if x := accts[0]; x.ID != 1 || x.Name != "ann" || x.Ships != 1 || x.SlotsUsed != 2 || x.Actions != 5 || x.LastLogin == 0 || x.LastAction == 0 {
		t.Errorf("ann's row: %+v", x)
	}
	if x := accts[1]; x.Name != "<img src=x onerror=alert(1)>" || x.Actions != 1 || x.LastLogin != 0 || x.SlotsUsed != 0 {
		t.Errorf("bob's row: %+v", x)
	}
	_ = bob

	var d struct {
		Name  string `json:"name"`
		Ships []struct {
			ID           int64  `json:"id"`
			Status       string `json:"status"`
			ProgramBytes int    `json:"program_bytes"`
		} `json:"ships"`
		Slots []struct {
			Slot int    `json:"slot"`
			Name string `json:"name"`
			Size int    `json:"size"`
		} `json:"slots"`
		Audit []auditRow `json:"audit"`
	}
	if err := json.Unmarshal(a.get("/admin/api/accounts/1", 200), &d); err != nil {
		t.Fatal(err)
	}
	if d.Name != "ann" || len(d.Ships) != 1 || d.Ships[0].Status != "launching" || d.Ships[0].ProgramBytes == 0 {
		t.Errorf("detail ships: %+v", d)
	}
	if len(d.Slots) != 2 || d.Slots[0].Slot != 4 || d.Slots[0].Name != "ALPHA" || d.Slots[1].Slot != 9 || d.Slots[0].Size != len("; alpha\nhalt") {
		t.Errorf("detail slots: %+v", d.Slots)
	}
	if len(d.Audit) != 5 || d.Audit[0].Action != "launch" {
		t.Errorf("detail audit: %d entries, first %v", len(d.Audit), d.Audit)
	}
	// Another account's actions do not leak into this one's.
	for _, r := range d.Audit {
		if r.PlayerID != 1 {
			t.Errorf("foreign entry in ann's audit: %+v", r)
		}
	}

	// The code saved in a slot can be read.
	var src struct {
		Name   string `json:"name"`
		Source string `json:"source"`
	}
	json.Unmarshal(a.get("/admin/api/accounts/1/slots/9", 200), &src)
	if src.Name != "OMEGA" || src.Source != "; omega\nhalt" {
		t.Errorf("slot source: %+v", src)
	}
	a.get("/admin/api/accounts/1/slots/12", 404) // empty
	a.get("/admin/api/accounts/1/slots/x", 400)
	a.get("/admin/api/accounts/99", 404)
	a.get("/admin/api/accounts/abc", 400)
	a.get("/admin/api/accounts/99/slots/4", 404)
}

func sha256hex(s string) string {
	return sha256HexOf([]byte(s))
}

func sha256HexOf(b []byte) string {
	h := sha256.Sum256(b)
	return hex.EncodeToString(h[:])
}