package main

import (
	"context"
	"encoding/json"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"testing"

	"xterm/internal/desktop"
)

type manifest struct {
	Capabilities []string `json:"capabilities"`
	Requires     []string `json:"requires"`
	Claims       []struct {
		Name   string   `json:"name"`
		Serves []string `json:"serves"`
	} `json:"claims"`
	Tools       []string `json:"tools"`
	Environment struct {
		Variables map[string]string `json:"variables"`
	} `json:"environment"`
	Shell []struct {
		For, Slot, Code string
	} `json:"shell"`
	Resources []map[string]any `json:"resources"`
	Build     struct {
		Artifacts []map[string]any `json:"artifacts"`
	} `json:"build"`
}

func readManifest(t *testing.T) manifest {
	raw, err := os.ReadFile(filepath.Join("..", "..", "module.json"))
	if err != nil {
		t.Fatal(err)
	}
	var m manifest
	if err := json.Unmarshal(raw, &m); err != nil {
		t.Fatal(err)
	}
	return m
}

func TestItHoldsTheTerminalSeatOnAnXDisplayAndNamesItselfTheTerminal(t *testing.T) {
	m := readManifest(t)
	if len(m.Claims) != 1 || m.Claims[0].Name != "node-terminal-emulator" || strings.Join(m.Claims[0].Serves, ",") != "open" {
		t.Fatalf("%+v", m.Claims)
	}
	if strings.Join(m.Requires, ",") != "x11-display" || m.Environment.Variables["TERMINAL"] != "xterm" || len(m.Environment.Variables) != 1 {
		t.Fatalf("%v %v", m.Requires, m.Environment)
	}
	served := map[string]bool{}
	for _, tool := range tools(xterm{}) {
		served[tool.Name] = true
	}
	if !served["node-terminal-emulator.open"] || len(served) != len(m.Tools)+1 {
		t.Fatalf("%v %v", served, m.Tools)
	}
	for _, n := range m.Tools {
		if !served[n] {
			t.Errorf("%s", n)
		}
	}
	if len(m.Resources) != 1 || m.Resources[0]["package"] != "xterm" {
		t.Fatalf("%v", m.Resources)
	}
	if a := m.Build.Artifacts[0]; a["binary"] != "xterm-tools" || a["from"] != "cmd/xterm-tools" {
		t.Fatalf("a binary not named xterm, so nothing looking for xterm by name finds the tools: %v", a)
	}
}

func TestItsResourcesAreOneContributionInTheNormalSlotScopedToXTerm(t *testing.T) {
	m := readManifest(t)
	if len(m.Shell) != 1 || m.Shell[0].For != "xresources" || m.Shell[0].Slot != "normal" {
		t.Fatalf("%+v", m.Shell)
	}
	if m.Shell[0].Code != Resources() {
		t.Fatal("the manifest's resources are not the ones the bundle describes: regenerate the manifest from Resources()")
	}
	for _, l := range strings.Split(strings.TrimSpace(Resources()), "\n") {
		switch {
		case strings.HasPrefix(l, "!"), strings.HasPrefix(l, "  "):
		case strings.HasPrefix(l, "#"):
			t.Errorf("merged with -nocpp, a # line is skipped: %q", l)
		case !strings.HasPrefix(l, "XTerm*"):
			t.Errorf("a resource of another program, or of every one: %q", l)
		}
	}
	if !strings.Contains(Resources(), "XTerm*faceName: JetBrainsMono Nerd Font") || !strings.Contains(Resources(), "copy-selection(CLIPBOARD)") {
		t.Fatal("the chosen face and the clipboard keys")
	}
}

type fake struct {
	ran   []string
	stdin []string
	query string
}

func (f *fake) desk(session bool) desktop.Desk {
	return desktop.Desk{
		Find: func() (*desktop.Session, error) {
			if !session {
				return nil, &desktop.NoSession{Reason: "none"}
			}
			return &desktop.Session{Display: ":1", XAuthority: "/h/.Xauthority", Type: "x11", RuntimeDir: "/run/user/1000", Bus: "unix:path=/run/user/1000/bus"}, nil
		},
		Run: func(_ context.Context, _ []string, stdin []byte, name string, args ...string) desktop.Result {
			f.ran = append(f.ran, strings.Join(append([]string{name}, args...), " "))
			f.stdin = append(f.stdin, string(stdin))
			switch name {
			case "xrdb":
				return desktop.Result{Stdout: f.query}
			case "fc-list":
				if strings.Contains(args[0], "Missing") {
					return desktop.Result{}
				}
				return desktop.Result{Stdout: args[0] + "\n"}
			case "fc-match":
				return desktop.Result{Stdout: "JetBrainsMono Nerd Font|Regular|/usr/share/fonts/TTF/J.ttf"}
			}
			return desktop.Result{}
		},
	}
}

func TestOpenHandsTheTerminalToTheAccountsServiceManagerWithTheSessionsDisplay(t *testing.T) {
	f := &fake{}
	dir := t.TempDir()
	got, err := xterm{d: f.desk(true)}.open(context.Background(), desktop.Args{"directory": dir, "command": "htop", "hold": true, "title": "top"})
	if err != nil {
		t.Fatal(err)
	}
	if len(f.ran) != 1 || !strings.HasPrefix(f.ran[0], "systemd-run --user --collect --quiet --unit=mesh-xterm-") {
		t.Fatalf("%q", f.ran)
	}
	for _, want := range []string{"--setenv=DISPLAY=:1", "--setenv=XAUTHORITY=/h/.Xauthority", "-- xterm -title top -hold -e /bin/sh -c", "sh " + dir + " htop"} {
		if !strings.Contains(f.ran[0], want) {
			t.Errorf("lacks %q: %s", want, f.ran[0])
		}
	}
	if !strings.Contains(asJSON(got), `"unit":"mesh-xterm-`) {
		t.Fatalf("%s", asJSON(got))
	}
	if _, err := (xterm{d: f.desk(true)}).open(context.Background(), desktop.Args{"directory": "/no/such/dir"}); err == nil {
		t.Fatal("a directory that is not there")
	}
	if _, err := (xterm{d: (&fake{}).desk(false)}).open(context.Background(), desktop.Args{}); !desktop.IsNoSession(err) {
		t.Fatalf("%v", err)
	}
}

func TestTheTerminalsScriptStartsInTheDirectoryAndRunsTheCommandThroughTheShell(t *testing.T) {
	dir := t.TempDir()
	args := OpenArgs(dir, "pwd > out", "", false)
	sh := args[len(args)-6:] // /bin/sh -c script sh dir command
	cmd := exec.Command(sh[0], sh[1:]...)
	cmd.Env = []string{"SHELL=/bin/sh", "PATH=/usr/bin:/bin", "HOME=" + dir}
	if out, err := cmd.CombinedOutput(); err != nil {
		t.Fatalf("%v %s", err, out)
	}
	b, _ := os.ReadFile(filepath.Join(dir, "out"))
	if strings.TrimSpace(string(b)) != dir {
		t.Fatalf("%q", b)
	}
}

func TestFontAndColoursAreReadAsAnXTermSeesThem(t *testing.T) {
	q := "*faceName:\tHack Nerd Font\nXTerm*faceName:\tJetBrainsMono Nerd Font\nXTerm*faceSize:\t12\n" +
		"XTerm*background:\t#000000\n*foreground:\trgb:a8/a8/a8\nXTerm*color1:\trgb:ff/00/00\n"
	if Effective(q, "faceName") != "JetBrainsMono Nerd Font" || Effective(q, "foreground") != "rgb:a8/a8/a8" {
		t.Fatal("XTerm's own value outranks the global one; the global one stands alone")
	}
	for in, want := range map[string]string{"rgb:9e/18/28": "#9e1828", "rgb:f/0/8": "#ff0088", "rgb:ffff/0000/8080": "#ff0080", "#ABCDEF": "#abcdef", "red": "red"} {
		if got := Hex(in); got != want {
			t.Errorf("%s: %s", in, got)
		}
	}
	f := &fake{query: q}
	got, err := xterm{d: f.desk(true)}.colours(context.Background(), desktop.Args{})
	if err != nil {
		t.Fatal(err)
	}
	j := asJSON(got)
	if !strings.Contains(j, `{"name":"color1","value":"#ff0000","default":"#9e1828","differs":true}`) || !strings.Contains(j, `{"name":"foreground","value":"#a8a8a8","default":"#a8a8a8"}`) {
		t.Fatalf("%s", j)
	}
	if _, err := (xterm{d: f.desk(true)}).font(context.Background(), desktop.Args{"face": "Missing Font"}); err == nil {
		t.Fatal("a face that is not installed")
	}
	if _, err := (xterm{d: f.desk(true)}).font(context.Background(), desktop.Args{"size": 99.0}); err == nil {
		t.Fatal("size out of range")
	}
	f.ran, f.stdin = nil, nil
	got, err = xterm{d: f.desk(true)}.font(context.Background(), desktop.Args{"face": "Inter", "size": 13.0})
	if err != nil {
		t.Fatal(err)
	}
	if f.stdin[1] != "XTerm*faceName: Inter\nXTerm*faceSize: 13\n" || !strings.Contains(asJSON(got), `"lasts"`) {
		t.Fatalf("%q %s", f.stdin, asJSON(got))
	}
}

func asJSON(v any) string {
	b, _ := json.Marshal(v)
	return string(b)
}