package domain

import (
	"fmt"
	"strings"
	"testing"
)

func TestXpForLevel(t *testing.T) {
	cases := []struct {
		n    int
		want int64
	}{
		{0, 0},
		{1, 100},
		{2, 300},
		{5, 1500},
		{10, 5500},
		{27, 37800},
		{50, 127500},
	}
	for _, c := range cases {
		got := XpForLevel(c.n)
		if got != c.want {
			t.Errorf("XpForLevel(%d) = %d, want %d", c.n, got, c.want)
		}
	}
}

func TestLevelForXP(t *testing.T) {
	cases := []struct {
		xp   int64
		want int
	}{
		{0, 0},
		{50, 0},
		{99, 0},
		{100, 1},
		{299, 1},
		{300, 2},
		{5500, 10},
		{37800, 27},
		{127500, 50},
	}
	for _, c := range cases {
		got := LevelForXP(c.xp)
		if got != c.want {
			t.Errorf("LevelForXP(%d) = %d, want %d", c.xp, got, c.want)
		}
	}
}

func TestLevelForXP_Monotonic(t *testing.T) {
	for n := 0; n <= 100; n++ {
		xp := XpForLevel(n)
		l := LevelForXP(xp)
		if l != n {
			t.Errorf("LevelForXP(XpForLevel(%d)) = %d, want %d", n, l, n)
		}
	}
}

func TestXpForWorkSeconds(t *testing.T) {
	if got := XpForWorkSeconds(0); got != 0 {
		t.Errorf("XpForWorkSeconds(0) = %d, want 0", got)
	}
	if got := XpForWorkSeconds(3600); got != 3600 {
		t.Errorf("XpForWorkSeconds(3600) = %d, want 3600", got)
	}
	if got := XpForWorkSeconds(1800); got != 1800 {
		t.Errorf("XpForWorkSeconds(1800) = %d, want 1800", got)
	}
}

func TestStreakBonus(t *testing.T) {
	cases := []struct {
		streak int
		want   int64
	}{
		{0, 0},
		{1, 50},
		{10, 500},
		{5, 250},
		{20, 500},
	}
	for _, c := range cases {
		got := StreakBonus(c.streak)
		if got != c.want {
			t.Errorf("StreakBonus(%d) = %d, want %d", c.streak, got, c.want)
		}
	}
}

func TestCurrencySymbol(t *testing.T) {
	cases := []struct {
		currency string
		want     string
	}{
		{"", "$"},
		{"$", "$"},
		{"$ USD", "$"},
		{"\u20AC EUR", "\u20AC"},
		{"\u00A3", "\u00A3"},
		{"Toman", "Toman"},
		{"   ", "$"},
	}
	for _, c := range cases {
		got := CurrencySymbol(c.currency)
		if got != c.want {
			t.Errorf("CurrencySymbol(%q) = %q, want %q", c.currency, got, c.want)
		}
	}
}

func TestComputeDailySalary(t *testing.T) {
	got := ComputeDailySalary(3600, 25.0)
	if got != 25.0 {
		t.Errorf("ComputeDailySalary(3600, 25) = %.2f, want 25.00", got)
	}

	got = ComputeDailySalary(9000, 20.0)
	if got != 50.0 {
		t.Errorf("ComputeDailySalary(9000, 20) = %.2f, want 50.00", got)
	}

	got = ComputeDailySalary(0, 50.0)
	if got != 0 {
		t.Errorf("ComputeDailySalary(0, 50) = %.2f, want 0", got)
	}

	got = ComputeDailySalary(3599, 10.0)
	if got != 10.0 {
		t.Errorf("ComputeDailySalary(3599, 10) = %.2f, want 10.00", got)
	}
}

func TestSanitizeNote(t *testing.T) {
	if got := SanitizeNote("  hello  "); got != "hello" {
		t.Errorf("SanitizeNote trim: got %q", got)
	}

	if got := SanitizeNote("he\x00llo\nworld\t!"); got != "hello\nworld\t!" {
		t.Errorf("SanitizeNote control: got %q", got)
	}

	if got := SanitizeNote("line1\nline2\tindented"); got != "line1\nline2\tindented" {
		t.Errorf("SanitizeNote newline/tab: got %q", got)
	}

	long := make([]byte, 600)
	for i := range long {
		long[i] = 'a'
	}
	got := SanitizeNote(string(long))
	if len(got) > 500 {
		t.Errorf("SanitizeNote length: got %d, want <= 500", len(got))
	}
}

func TestSanitizeDisplayName(t *testing.T) {
	if got := SanitizeDisplayName("  Alice  "); got != "Alice" {
		t.Errorf("SanitizeDisplayName trim: got %q", got)
	}
	if got := SanitizeDisplayName("Ali\x00ce"); got != "Alice" {
		t.Errorf("SanitizeDisplayName control: got %q", got)
	}
	if got := SanitizeDisplayName(""); got != "" {
		t.Errorf("SanitizeDisplayName empty: got %q", got)
	}
}

func TestParseCurrencyInput(t *testing.T) {
	cases := []struct {
		input string
		want  string
		ok    bool
	}{
		{"$ USD", "$ USD", true},
		{"T Toman", "T Toman", true},
		{"IRR Rial", "IRR Rial", true},
		{"\u20AC EUR", "\u20AC EUR", true},
		{"", "", false},
		{"$", "", false},
		{"   ", "", false},
		{"$$$ TooLongCode", "", false},
	}
	for _, c := range cases {
		got, errMsg := ParseCurrencyInput(c.input)
		if c.ok && (got != c.want || errMsg != "") {
			t.Errorf("ParseCurrencyInput(%q) = (%q, %q), want (%q, \"\")", c.input, got, errMsg, c.want)
		}
		if !c.ok && errMsg == "" {
			t.Errorf("ParseCurrencyInput(%q) = (%q, \"\"), want error", c.input, got)
		}
	}
}

func TestComputeTrendFromAvgs(t *testing.T) {
	cases := []struct {
		recent, older float64
		wantPts       int
		wantDirSub    string
	}{
		{0, 0, 5, "stable"},
		{100, 0, 15, "new"},
		{0, 100, 0, "-100"},
		{121, 100, 15, "+21"},
		{100, 100, 5, "stable"},
		{100, 130, 0, "-23"},
	}
	for _, c := range cases {
		pts, dir := ComputeTrendFromAvgs(c.recent, c.older)
		if pts != c.wantPts {
			t.Errorf("ComputeTrendFromAvgs(%.0f, %.0f) pts = %d, want %d", c.recent, c.older, pts, c.wantPts)
		}
		if !strings.Contains(dir, c.wantDirSub) {
			t.Errorf("ComputeTrendFromAvgs(%.0f, %.0f) dir = %q, want containing %q", c.recent, c.older, dir, c.wantDirSub)
		}
	}
}

func TestComputeStreakFromDates_Empty(t *testing.T) {
	cur, longest := ComputeStreakFromDates(nil, "2026-06-25")
	if cur != 0 || longest != 0 {
		t.Errorf("empty dates: got (%d, %d), want (0, 0)", cur, longest)
	}
}

func TestComputeStreakFromDates_CurrentOnly(t *testing.T) {
	dates := []string{"2026-06-25", "2026-06-26"}
	cur, longest := ComputeStreakFromDates(dates, "2026-06-26")
	if cur != 2 {
		t.Errorf("current streak = %d, want 2", cur)
	}
	if longest != 2 {
		t.Errorf("longest streak = %d, want 2", longest)
	}
}

func TestComputeStreakFromDates_GapBreaksStreak(t *testing.T) {
	dates := []string{"2026-06-23", "2026-06-25", "2026-06-26"}
	cur, longest := ComputeStreakFromDates(dates, "2026-06-26")
	if cur != 2 {
		t.Errorf("current streak = %d, want 2 (today and yesterday)", cur)
	}
	if longest != 2 {
		t.Errorf("longest streak = %d, want 2", longest)
	}
}

func TestComputeStreakFromDates_NoEventsToday(t *testing.T) {
	dates := []string{"2026-06-24", "2026-06-25"}
	cur, longest := ComputeStreakFromDates(dates, "2026-06-26")
	if cur != 0 {
		t.Errorf("current streak = %d, want 0 (no events today)", cur)
	}
	if longest != 2 {
		t.Errorf("longest streak = %d, want 2", longest)
	}
}

func TestComputeStreakFromDates_LongStreak(t *testing.T) {
	dates := make([]string, 0, 10)
	for d := 1; d <= 10; d++ {
		dates = append(dates, fmt.Sprintf("2026-06-%02d", d))
	}
	cur, longest := ComputeStreakFromDates(dates, "2026-06-10")
	if cur != 10 {
		t.Errorf("current streak = %d, want 10", cur)
	}
	if longest != 10 {
		t.Errorf("longest streak = %d, want 10", longest)
	}
}

func TestComputeStreakFromDates_LongestNotCurrent(t *testing.T) {
	dates := []string{}
	for d := 1; d <= 5; d++ {
		dates = append(dates, formatDateInt(2026, 6, d))
	}
	dates = append(dates, "2026-06-09", "2026-06-10")
	cur, longest := ComputeStreakFromDates(dates, "2026-06-10")
	if cur != 2 {
		t.Errorf("current streak = %d, want 2", cur)
	}
	if longest != 5 {
		t.Errorf("longest streak = %d, want 5", longest)
	}
}

func formatDateInt(y, m, d int) string {
	return FormatDateForCalendar(
		func() string {
			s := make([]byte, 10)
			s[0] = byte('0' + y/1000)
			s[1] = byte('0' + (y/100)%10)
			s[2] = byte('0' + (y/10)%10)
			s[3] = byte('0' + y%10)
			s[4] = '-'
			s[5] = byte('0' + m/10)
			s[6] = byte('0' + m%10)
			s[7] = '-'
			s[8] = byte('0' + d/10)
			s[9] = byte('0' + d%10)
			return string(s)
		}(), "gregorian")
}