package main

import (
	"context"
	"os"
	"path/filepath"
	"regexp"
	"strconv"
	"strings"
	"testing"

	"xterm/internal/desktop"
)

// todaysResources is the file every machine had before the module took config values (novox/hq issue 1656).
var todaysResources = strings.Join([]string{
	"! xterm: the face, the palette and the clipboard keys. Scoped to the XTerm class, so they",
	"! outrank any `*name` resource of yours and touch no other X program.",
	"XTerm*termName: xterm-256color",
	"XTerm*saveLines: 10000",
	"XTerm*renderFont: true",
	"XTerm*faceName: JetBrainsMono Nerd Font",
	"XTerm*faceSize: 12",
	"XTerm*boldMode: false",
	"XTerm*alwaysBoldMode: false",
	"XTerm*allowBoldFonts: true",
	"XTerm*background: #000000",
	"XTerm*foreground: #a8a8a8",
	"XTerm*color0: #000000",
	"XTerm*color8: #666666",
	"XTerm*color1: #9e1828",
	"XTerm*color9: #bc5766",
	"XTerm*color2: #008800",
	"XTerm*color10: #61a171",
	"XTerm*color3: #d2bb4b",
	"XTerm*color11: #e7db52",
	"XTerm*color4: #414171",
	"XTerm*color12: #5085af",
	"XTerm*color5: #963c59",
	"XTerm*color13: #a97a99",
	"XTerm*color6: #418179",
	"XTerm*color14: #6ba4a4",
	"XTerm*color7: #bebebe",
	"XTerm*color15: #ffffff",
	"XTerm*VT100.Translations: #override \\n\\",
	"  Ctrl Shift ~Alt <Key> C: copy-selection(CLIPBOARD) \\n\\",
	"  Ctrl Shift ~Alt <Key> V: insert-selection(CLIPBOARD)",
	"",
}, "\n")

var placeholder = regexp.MustCompile(`\$\{config:([a-z0-9][a-z0-9_.-]*)\}`)

// asText is a default as the controller writes a value into a file: a string as it is, a number without a
// needless fraction, a boolean as true or false.
func asText(t *testing.T, v any) string {
	t.Helper()
	switch v := v.(type) {
	case string:
		return v
	case float64:
		return strconv.FormatFloat(v, 'f', -1, 64)
	case bool:
		return strconv.FormatBool(v)
	}
	t.Fatalf("a default of no type: %v", v)
	return ""
}

func template(t *testing.T) string {
	t.Helper()
	m := readManifest(t)
	if len(m.Shell) != 1 {
		t.Fatalf("%+v", m.Shell)
	}
	return m.Shell[0].Code
}

// 1656/AC1: every value the resources set is a config value with today's value as its default.
func TestEveryResourceValueIsAConfigValueWithTodaysDefault(t *testing.T) {
	m := readManifest(t)
	want := map[string]any{
		"face": "JetBrainsMono Nerd Font", "size": 12.0, "save-lines": 10000.0, "term-name": "xterm-256color",
		"render-font": true, "bold-mode": false, "always-bold-mode": false, "allow-bold-fonts": true,
		"background": "#000000", "foreground": "#a8a8a8",
		"color0": "#000000", "color1": "#9e1828", "color2": "#008800", "color3": "#d2bb4b",
		"color4": "#414171", "color5": "#963c59", "color6": "#418179", "color7": "#bebebe",
		"color8": "#666666", "color9": "#bc5766", "color10": "#61a171", "color11": "#e7db52",
		"color12": "#5085af", "color13": "#a97a99", "color14": "#6ba4a4", "color15": "#ffffff",
		"copy-binding": "Ctrl Shift ~Alt <Key> C", "paste-binding": "Ctrl Shift ~Alt <Key> V",
	}
	if len(m.Config) != len(want) {
		t.Errorf("declares %d config values, want %d", len(m.Config), len(want))
	}
	for key, def := range want {
		c, ok := m.Config[key]
		if !ok {
			t.Errorf("%s: not declared", key)
			continue
		}
		if c.Default != def || c.Required || strings.TrimSpace(c.Description) == "" {
			t.Errorf("%s: %+v, want default %v and a description", key, c, def)
		}
		wantType := map[bool]string{true: "string"}[true]
		switch def.(type) {
		case float64:
			wantType = "number"
		case bool:
			wantType = "boolean"
		}
		if c.Type != wantType {
			t.Errorf("%s: type %q, want %q", key, c.Type, wantType)
		}
	}
	size := m.Config["size"]
	if size.Predefined != "font-size" || size.Minimum == nil || *size.Minimum != 6 || size.Maximum == nil || *size.Maximum != 72 {
		t.Errorf("size: %+v, want the predefined font-size from 6 to 72", size)
	}
	names := []string{"background", "foreground"}
	for i := 0; i < 16; i++ {
		names = append(names, "color"+strconv.Itoa(i))
	}
	for _, key := range names {
		c := m.Config[key]
		re, err := regexp.Compile("^(?:" + c.Pattern + ")$")
		if err != nil || c.Pattern == "" {
			t.Errorf("%s: pattern %q", key, c.Pattern)
			continue
		}
		if !re.MatchString("#0a1B2c") || re.MatchString("red") || re.MatchString("#12345") || re.MatchString("#1234567") {
			t.Errorf("%s: pattern %q is not #rrggbb", key, c.Pattern)
		}
	}
	for _, key := range []string{"copy-binding", "paste-binding"} {
		re := regexp.MustCompile("^(?:" + m.Config[key].Pattern + ")$")
		if !re.MatchString("Ctrl Shift ~Alt <Key> C") || re.MatchString("a: b") || re.MatchString("a\nb") || re.MatchString(`a\`) {
			t.Errorf("%s: pattern %q lets a value end the resource", key, m.Config[key].Pattern)
		}
	}
}

// 1656/AC2: no literal value is left in the resources, and every declared key is used.
func TestEveryResourceValueIsAPlaceholderOfADeclaredKeyAndEveryKeyIsUsed(t *testing.T) {
	m := readManifest(t)
	text := template(t)
	used := map[string]bool{}
	for _, l := range strings.Split(text, "\n") {
		switch {
		case l == "", strings.HasPrefix(l, "!"):
			continue
		case strings.HasPrefix(l, "XTerm*VT100.Translations: #override"):
			continue
		}
		_, value, ok := strings.Cut(l, ": ")
		if strings.HasPrefix(l, "  ") {
			// a translation line: `<binding>: <action> \n\`
			value, _, _ = strings.Cut(strings.TrimSpace(l), ": ")
			ok = true
		}
		if !ok {
			t.Errorf("not a resource: %q", l)
			continue
		}
		f := placeholder.FindStringSubmatch(value)
		if f == nil || f[0] != value {
			t.Errorf("a literal value, not a ${config:<key>}: %q", l)
			continue
		}
		if _, declared := m.Config[f[1]]; !declared {
			t.Errorf("%q names a key the module does not declare", l)
		}
		used[f[1]] = true
	}
	for key := range m.Config {
		if !used[key] {
			t.Errorf("%s is declared and no resource uses it", key)
		}
	}
}

// 1656/AC3: filled with the defaults, the resources are the file every machine had.
func TestFilledWithTheDefaultsTheResourcesAreTodaysFileByteForByte(t *testing.T) {
	m := readManifest(t)
	got := placeholder.ReplaceAllStringFunc(template(t), func(ref string) string {
		c, ok := m.Config[placeholder.FindStringSubmatch(ref)[1]]
		if !ok {
			t.Fatalf("%s: no such key", ref)
		}
		return asText(t, c.Default)
	})
	if got != todaysResources {
		t.Fatalf("filled with the defaults:\n%s\nwant:\n%s", got, todaysResources)
	}
}

// renderedWith is the resources file xorg writes with this module's piece filled from the defaults, and
// the given values changed.
func renderedWith(t *testing.T, changed map[string]string) string {
	t.Helper()
	m := readManifest(t)
	text := placeholder.ReplaceAllStringFunc(template(t), func(ref string) string {
		key := placeholder.FindStringSubmatch(ref)[1]
		if v, ok := changed[key]; ok {
			return v
		}
		return asText(t, m.Config[key].Default)
	})
	return "! The mesh's X resources (module xorg)\nXft.dpi: 96\n# xterm\n" + text + "Xft.rgba: rgb\n"
}

func deskWithResources(t *testing.T, rendered string, f *fake) xterm {
	t.Helper()
	path := filepath.Join(t.TempDir(), "xresources")
	if rendered != "" {
		if err := os.WriteFile(path, []byte(rendered), 0o644); err != nil {
			t.Fatal(err)
		}
	}
	return xterm{d: f.desk(true), resources: path}
}

// 1656/AC4: the tools' defaults are what the module's resources were rendered with, not constants.
func TestFontReportsTheDefaultTheModuleRenderedNotAConstant(t *testing.T) {
	f := &fake{query: "XTerm*faceName:\tInter\nXTerm*faceSize:\t13\n"}
	x := deskWithResources(t, renderedWith(t, map[string]string{"size": "10", "face": "Fira Code"}), f)
	got, err := x.font(context.Background(), desktop.Args{})
	if err != nil {
		t.Fatal(err)
	}
	if j := asJSON(got); !strings.Contains(j, `"default":{"face":"Fira Code","size":10}`) {
		t.Fatalf("%s", j)
	}
}

// 1656/AC4
func TestColoursReportTheDefaultTheModuleRenderedNotAConstant(t *testing.T) {
	f := &fake{query: "XTerm*color1:\t#aa0000\nXTerm*foreground:\t#112233\nXTerm*color2:\trgb:00/88/01\n"}
	x := deskWithResources(t, renderedWith(t, map[string]string{"color1": "#aa0000", "foreground": "#112233"}), f)
	got, err := x.colours(context.Background(), desktop.Args{})
	if err != nil {
		t.Fatal(err)
	}
	j := asJSON(got)
	for _, want := range []string{`{"name":"color1","value":"#aa0000","default":"#aa0000"}`,
		`{"name":"foreground","value":"#112233","default":"#112233"}`,
		`{"name":"color2","value":"#008801","default":"#008800","differs":true}`} {
		if !strings.Contains(j, want) {
			t.Errorf("lacks %s in %s", want, j)
		}
	}
}

// 1656/AC4: without the rendered file there is no default to report, said loudly.
func TestWithoutTheRenderedResourcesTheToolsSayWhy(t *testing.T) {
	x := deskWithResources(t, "", &fake{})
	if _, err := x.font(context.Background(), desktop.Args{}); err == nil || !strings.Contains(err.Error(), "xresources") {
		t.Fatalf("font: %v", err)
	}
	if _, err := x.colours(context.Background(), desktop.Args{}); err == nil || !strings.Contains(err.Error(), "xresources") {
		t.Fatalf("colours: %v", err)
	}
}

// 1656/AC4: tools.go holds no copy of the defaults.
func TestTheToolsHoldNoCopyOfTheDefaults(t *testing.T) {
	src, err := os.ReadFile("tools.go")
	if err != nil {
		t.Fatal(err)
	}
	for _, lit := range []string{"JetBrainsMono", "#a8a8a8", "#9e1828", "xterm-256color", "Face =", "Size =", "func Resources"} {
		if strings.Contains(string(src), lit) {
			t.Errorf("tools.go holds %q", lit)
		}
	}
}