package main

import (
	"bytes"
	"os"
	"strings"
	"testing"
)

// pipeFile is a real *os.File that is NOT a terminal — the shape every CI
// run, every `| less` and every e2e test's exec'd binary sees.
func pipeFile(t *testing.T) *os.File {
	t.Helper()
	r, w, err := os.Pipe()
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { r.Close(); w.Close() })
	return w
}

func TestColorEnabledPrecedence(t *testing.T) {
	f := pipeFile(t)
	cases := []struct {
		name string
		env  map[string]string
		want bool
	}{
		{"pipe with a terminal set", map[string]string{"TERM": "xterm-256color"}, false},
		{"CARLOS_COLOR=always beats the pipe", map[string]string{"TERM": "xterm", "CARLOS_COLOR": "always"}, true},
		{"CARLOS_COLOR=always beats NO_COLOR", map[string]string{"TERM": "xterm", "CARLOS_COLOR": "always", "NO_COLOR": "1"}, true},
		{"CARLOS_COLOR=never", map[string]string{"TERM": "xterm", "CARLOS_COLOR": "never"}, false},
		{"NO_COLOR", map[string]string{"TERM": "xterm", "NO_COLOR": "1"}, false},
		{"TERM=dumb", map[string]string{"TERM": "dumb", "CARLOS_COLOR": ""}, false},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			for _, k := range []string{"TERM", "NO_COLOR", "CARLOS_COLOR"} {
				t.Setenv(k, tc.env[k])
			}
			if got := colorEnabled(f); got != tc.want {
				t.Fatalf("colorEnabled = %v, want %v", got, tc.want)
			}
		})
	}
}

// A buffer is what the CLI's print seam holds under test. It must never be
// coloured, whatever the environment says — including CARLOS_COLOR=always,
// because an operator with that set in their shell would otherwise see every
// in-process test fail on escape codes.
func TestColorForNonFileIsAlwaysPlain(t *testing.T) {
	t.Setenv("CARLOS_COLOR", "always")
	t.Setenv("TERM", "xterm-256color")
	var buf bytes.Buffer
	if c := colorFor(&buf); c.on {
		t.Fatal("a bytes.Buffer was given a colour palette")
	}
	mutedf(&buf, "using %s as %s", "https://console.example", "vicky@keymail.dev")
	if got, want := buf.String(), "using https://console.example as vicky@keymail.dev\n"; got != want {
		t.Fatalf("mutedf wrote %q, want %q", got, want)
	}
}

func TestPaletteWrapsOnlyWhenOn(t *testing.T) {
	on := colors{on: true}
	if got, want := on.ok("shipped"), ansiGreen+"shipped"+ansiReset; got != want {
		t.Fatalf("ok = %q, want %q", got, want)
	}
	if got := on.muted(""); got != "" {
		t.Fatalf("an empty string got wrapped: %q", got)
	}
	off := colors{}
	for name, got := range map[string]string{
		"muted": off.muted("x"), "ok": off.ok("x"), "warn": off.warn("x"),
		"bad": off.bad("x"), "head": off.head("x"), "link": off.link("x"),
	} {
		if got != "x" {
			t.Fatalf("%s with colour off = %q, want %q", name, got, "x")
		}
	}
}

// The point of table's buffering: escape codes on the header must not be
// counted as column content. If they were, every row below would be padded
// to the header's inflated width.
func TestTableHeaderStylingDoesNotMoveColumns(t *testing.T) {
	rows := func(w *table) {
		w.Write([]byte("CHANNEL\tVERSION\tPROMOTED\n"))
		w.Write([]byte("canary/keymail\t1.2.3\t2026-08-07\n"))
		w.Write([]byte("stable\t1.0.0\t2026-08-01\n"))
	}

	var plain bytes.Buffer
	pt := newTable(&plain)
	rows(pt)
	if err := pt.Flush(); err != nil {
		t.Fatal(err)
	}

	var styled bytes.Buffer
	st := newTable(&styled)
	st.pal = colors{on: true} // a buffer never gets colour on its own
	rows(st)
	if err := st.Flush(); err != nil {
		t.Fatal(err)
	}

	got := styled.String()
	if !strings.HasPrefix(got, ansiBold+"CHANNEL") {
		t.Fatalf("header not styled: %q", got[:40])
	}
	// Strip the codes back out and the two renderings must be identical:
	// the columns did not move.
	stripped := strings.NewReplacer(ansiBold, "", ansiReset, "").Replace(got)
	if stripped != plain.String() {
		t.Fatalf("styling changed the layout:\n plain: %q\nstyled: %q", plain.String(), stripped)
	}
}

// Colour off, the banner is byte-for-byte the line the API-mode tests pin.
func TestPrintUsingIsUnchangedWithoutColor(t *testing.T) {
	var buf bytes.Buffer
	printUsing(&buf, &apiSession{console: "https://console.example", address: "vicky@keymail.dev"})
	if got, want := buf.String(), "using https://console.example as vicky@keymail.dev\n"; got != want {
		t.Fatalf("printUsing wrote %q, want %q", got, want)
	}
}