package client

import (
	"context"
	"errors"
	"io"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"time"

	"github.com/iceBear67/simplepages/api"
)

const testToken = "pgs_abcdefghijklmnop_ThisIsTheSecretHalfAndMustNotLeakAnywhere"

func TestNewValidatesConfig(t *testing.T) {
	cases := []struct {
		desc    string
		cfg     Config
		wantErr string
	}{
		{"no server", Config{Token: testToken}, "no server URL"},
		{"no token", Config{BaseURL: "https://p.example.com"}, "no token"},
		{"missing scheme", Config{BaseURL: "p.example.com", Token: testToken}, "missing scheme"},
		{"wrong scheme", Config{BaseURL: "ftp://p.example.com", Token: testToken}, "scheme must be http or https"},
		{"missing host", Config{BaseURL: "https://", Token: testToken}, "missing host"},
	}
	for _, tc := range cases {
		t.Run(tc.desc, func(t *testing.T) {
			_, err := New(tc.cfg)
			if err == nil || !strings.Contains(err.Error(), tc.wantErr) {
				t.Fatalf("err = %v, want one containing %q", err, tc.wantErr)
			}
			// A rejected URL is echoed back so the operator can see the typo, but
			// the token must never turn up in a message they might paste anywhere.
			if err != nil && strings.Contains(err.Error(), testToken) {
				t.Error("error message contains the token")
			}
		})
	}
}

func TestNewTrimsTrailingSlash(t *testing.T) {
	c, err := New(Config{BaseURL: "https://p.example.com/", Token: testToken})
	if err != nil {
		t.Fatal(err)
	}
	if got := c.BaseURL(); got != "https://p.example.com" {
		t.Errorf("BaseURL = %q, want no trailing slash", got)
	}
}

// TestRequestCarriesTokenInHeaderOnly is the wire half of the rule that a
// token never reaches a proxy access log: it belongs in Authorization, and
// nowhere near the URL.
func TestRequestCarriesTokenInHeaderOnly(t *testing.T) {
	var gotAuth, gotURL, gotAccept, gotAgent string
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		gotAuth, gotURL = r.Header.Get("Authorization"), r.URL.String()
		gotAccept, gotAgent = r.Header.Get("Accept"), r.Header.Get("User-Agent")
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"key_id":"abcdefghijklmnop","scope":"admin"}`))
	}))
	defer srv.Close()

	c, err := New(Config{BaseURL: srv.URL, Token: testToken})
	if err != nil {
		t.Fatal(err)
	}
	who, err := c.WhoAmI(context.Background())
	if err != nil {
		t.Fatal(err)
	}
	if who.KeyID != "abcdefghijklmnop" || who.Scope != "admin" {
		t.Errorf("decoded %+v", who)
	}
	if gotAuth != "Bearer "+testToken {
		t.Errorf("Authorization = %q", gotAuth)
	}
	if strings.Contains(gotURL, "pgs_") {
		t.Errorf("token reached the URL: %q", gotURL)
	}
	if gotAccept != "application/json" {
		t.Errorf("Accept = %q", gotAccept)
	}
	if !strings.HasPrefix(gotAgent, "pages/") {
		t.Errorf("User-Agent = %q", gotAgent)
	}
}

// TestRedirectIsRefused: following a redirect would send the bearer token to a
// host the operator never named.
func TestRedirectIsRefused(t *testing.T) {
	elsewhere := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		t.Errorf("request followed the redirect and reached %s", r.Host)
	}))
	defer elsewhere.Close()

	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		http.Redirect(w, r, elsewhere.URL+r.URL.Path, http.StatusFound)
	}))
	defer srv.Close()

	c, _ := New(Config{BaseURL: srv.URL, Token: testToken})
	_, err := c.WhoAmI(context.Background())
	if err == nil {
		t.Fatal("expected an error")
	}
	if !strings.Contains(err.Error(), "redirected") {
		t.Errorf("err = %v, want it to explain the redirect", err)
	}
}

func TestErrorResponses(t *testing.T) {
	cases := []struct {
		desc        string
		status      int
		body        string
		contentType string
		wantCode    api.Code
		wantMsg     string
	}{
		{
			desc:     "server envelope is used verbatim",
			status:   http.StatusConflict,
			body:     `{"error":{"code":"project_exists","message":"project demo already exists"}}`,
			wantCode: "project_exists",
			wantMsg:  "project demo already exists",
		},
		{
			desc:     "a bare proxy error still gets a code from the status",
			status:   http.StatusForbidden,
			body:     "<html>403 Forbidden</html>",
			wantCode: api.CodeForbidden,
			wantMsg:  "<html>403 Forbidden</html>",
		},
		{
			desc:     "an empty body falls back to the status text",
			status:   http.StatusBadGateway,
			body:     "",
			wantCode: api.CodeInternal,
			wantMsg:  "Bad Gateway",
		},
		{
			desc:     "an envelope without a code is not an envelope",
			status:   http.StatusNotFound,
			body:     `{"error":{"message":"nope"}}`,
			wantCode: api.CodeNotFound,
			wantMsg:  `{"error":{"message":"nope"}}`,
		},
	}
	for _, tc := range cases {
		t.Run(tc.desc, func(t *testing.T) {
			srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
				w.WriteHeader(tc.status)
				w.Write([]byte(tc.body))
			}))
			defer srv.Close()

			c, _ := New(Config{BaseURL: srv.URL, Token: testToken})
			_, err := c.WhoAmI(context.Background())

			var apiErr *api.Error
			if !errors.As(err, &apiErr) {
				t.Fatalf("err = %v (%T), want *api.Error", err, err)
			}
			if apiErr.Code != tc.wantCode {
				t.Errorf("code = %q, want %q", apiErr.Code, tc.wantCode)
			}
			if apiErr.Message != tc.wantMsg {
				t.Errorf("message = %q, want %q", apiErr.Message, tc.wantMsg)
			}
		})
	}
}

// TestHugeErrorBodyIsTruncated: a wrong --server can point at something that
// answers every request with a megabyte of HTML.
func TestHugeErrorBodyIsTruncated(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusBadRequest)
		w.Write([]byte(strings.Repeat("x", 1<<20)))
	}))
	defer srv.Close()

	c, _ := New(Config{BaseURL: srv.URL, Token: testToken})
	_, err := c.WhoAmI(context.Background())
	if err == nil {
		t.Fatal("expected an error")
	}
	if len(err.Error()) > 400 {
		t.Errorf("error message is %d bytes; it should be truncated", len(err.Error()))
	}
}

func TestNoContentNeedsNoBody(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodDelete {
			t.Errorf("method = %s", r.Method)
		}
		w.WriteHeader(http.StatusNoContent)
	}))
	defer srv.Close()

	c, _ := New(Config{BaseURL: srv.URL, Token: testToken})
	if err := c.DeleteProject(context.Background(), "demo"); err != nil {
		t.Fatalf("DeleteProject: %v", err)
	}
}

// TestTimeoutSaysWhichFlagToRaise — the timeout is the one failure a user can
// fix from the message alone, so the message has to name the flag.
func TestTimeoutSaysWhichFlagToRaise(t *testing.T) {
	release := make(chan struct{})
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		<-release
	}))
	defer func() { close(release); srv.Close() }()

	c, _ := New(Config{BaseURL: srv.URL, Token: testToken, Timeout: 50 * time.Millisecond})
	_, err := c.WhoAmI(context.Background())
	if err == nil {
		t.Fatal("expected a timeout")
	}
	if !strings.Contains(err.Error(), "--timeout") {
		t.Errorf("err = %v, want it to mention --timeout", err)
	}
}

// TestDeploymentQueriesTravelInTheURL. State, limit and cursor are the three
// knobs of a deployment listing and all three ride the query string; one that
// went missing would leave a listing that quietly answers a different question.
func TestDeploymentQueriesTravelInTheURL(t *testing.T) {
	var got string
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		got = r.URL.RequestURI()
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"deployments":[]}`))
	}))
	defer srv.Close()

	c, _ := New(Config{BaseURL: srv.URL, Token: testToken})
	ctx := context.Background()
	list := api.PathDeployments("demo")
	one := api.PathDeployment("demo", "dpl_1")

	cases := []struct {
		desc string
		call func() error
		want string
	}{
		{
			"no options, no query",
			func() error { _, err := c.ListDeployments(ctx, "demo", DeploymentListOptions{}); return err },
			list,
		},
		{
			"every option set",
			func() error {
				opts := DeploymentListOptions{State: "ready"}
				opts.Limit, opts.Cursor = 50, "dpl_9"
				_, err := c.ListDeployments(ctx, "demo", opts)
				return err
			},
			list + "?cursor=dpl_9&limit=50&state=ready",
		},
		{
			"a manifest is not fetched by default",
			func() error { _, err := c.GetDeployment(ctx, "demo", "dpl_1", false); return err },
			one,
		},
		{
			"asking for the manifest",
			func() error { _, err := c.GetDeployment(ctx, "demo", "dpl_1", true); return err },
			one + "?files=true",
		},
	}
	for _, tc := range cases {
		t.Run(tc.desc, func(t *testing.T) {
			if err := tc.call(); err != nil {
				t.Fatal(err)
			}
			if got != tc.want {
				t.Errorf("requested %q, want %q", got, tc.want)
			}
		})
	}
}

// TestUpkeepPostsItsFlag: a --dry-run that silently ran for real, or a fsck
// that repaired without being asked, are the two ways these calls can be
// dangerous, and both live in the request body.
func TestUpkeepPostsItsFlag(t *testing.T) {
	var gotMethod, gotPath, gotBody string
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		body, _ := io.ReadAll(r.Body)
		gotMethod, gotPath, gotBody = r.Method, r.URL.Path, string(body)
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{}`))
	}))
	defer srv.Close()

	c, _ := New(Config{BaseURL: srv.URL, Token: testToken})
	ctx := context.Background()

	if _, err := c.Collect(ctx, true); err != nil {
		t.Fatal(err)
	}
	if gotMethod != http.MethodPost || gotPath != api.PathGC() {
		t.Errorf("collect sent %s %s", gotMethod, gotPath)
	}
	if !strings.Contains(gotBody, `"dry_run":true`) {
		t.Errorf("collect body = %q, want dry_run set", gotBody)
	}

	if _, err := c.Fsck(ctx, true); err != nil {
		t.Fatal(err)
	}
	if gotMethod != http.MethodPost || gotPath != api.PathFsck() {
		t.Errorf("fsck sent %s %s", gotMethod, gotPath)
	}
	if !strings.Contains(gotBody, `"repair":true`) {
		t.Errorf("fsck body = %q, want repair set", gotBody)
	}
}

// TestListAllProjectsFollowsTheCursor: paging is invisible to the CLI, so the
// only place it can break is here.
func TestListAllProjectsFollowsTheCursor(t *testing.T) {
	var seen []string
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		cursor := r.URL.Query().Get("cursor")
		seen = append(seen, cursor)
		w.Header().Set("Content-Type", "application/json")
		switch cursor {
		case "":
			w.Write([]byte(`{"projects":[{"name":"a"},{"name":"b"}],"next_cursor":"b"}`))
		case "b":
			w.Write([]byte(`{"projects":[{"name":"c"}]}`))
		default:
			t.Errorf("unexpected cursor %q", cursor)
		}
	}))
	defer srv.Close()

	c, _ := New(Config{BaseURL: srv.URL, Token: testToken})
	got, err := c.ListAllProjects(context.Background())
	if err != nil {
		t.Fatal(err)
	}
	var names []string
	for _, p := range got {
		names = append(names, p.Name)
	}
	if strings.Join(names, ",") != "a,b,c" {
		t.Errorf("projects = %v, want a,b,c", names)
	}
	if len(seen) != 2 || seen[0] != "" || seen[1] != "b" {
		t.Errorf("cursors requested = %q", seen)
	}
}