package analytics

import (
	"encoding/base64"
	"errors"
	"testing"
	"time"
)

func TestDetailFilterValidate(t *testing.T) {
	t.Parallel()
	zero := int64(0)
	hundred := int64(100)
	twoHundred := int64(200)
	tests := []struct {
		name    string
		filter  DetailFilter
		wantErr bool
	}{
		{name: "all transactions", filter: DetailFilter{View: "ALL", Limit: 25}},
		{name: "allowlisted status", filter: DetailFilter{View: "ALL", Status: "Verified", Limit: 25}},
		{name: "amount range", filter: DetailFilter{View: "ALL", MinAmountRial: &zero, MaxAmountRial: &hundred, Limit: 25}},
		{name: "failed observed stage", filter: DetailFilter{View: "FAILED", FailureStage: "REACHED_BANK", Limit: 25}},
		{name: "unknown view", filter: DetailFilter{View: "EVERYTHING", Limit: 25}, wantErr: true},
		{name: "unknown status", filter: DetailFilter{View: "ALL", Status: "Successful", Limit: 25}, wantErr: true},
		{name: "stage outside failed view", filter: DetailFilter{View: "ALL", FailureStage: "NO_ATTEMPT", Limit: 25}, wantErr: true},
		{name: "descending amount range", filter: DetailFilter{View: "ALL", MinAmountRial: &twoHundred, MaxAmountRial: &hundred, Limit: 25}, wantErr: true},
		{name: "page too large", filter: DetailFilter{View: "ALL", Limit: 101}, wantErr: true},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			err := tt.filter.Validate()
			if (err != nil) != tt.wantErr {
				t.Fatalf("Validate() error = %v, wantErr %v", err, tt.wantErr)
			}
		})
	}
}

func TestSessionSourceKey(t *testing.T) {
	t.Parallel()
	tests := []struct {
		name, input, want string
		valid             bool
	}{
		{name: "valid opaque id", input: "ses_abc-123", want: "abc-123", valid: true},
		{name: "missing prefix", input: "abc-123"},
		{name: "empty source", input: "ses_"},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got, valid := sessionSourceKey(tt.input)
			if got != tt.want || valid != tt.valid {
				t.Fatalf("sessionSourceKey(%q) = %q,%v, want %q,%v", tt.input, got, valid, tt.want, tt.valid)
			}
		})
	}
}

func TestTerminalDisplayName(t *testing.T) {
	t.Parallel()
	if got := terminalDisplayName("terminal-12345678"); got != "پایانه ۵۶۷۸" {
		t.Fatalf("terminalDisplayName() = %q", got)
	}
}

func TestDetailCursorRejectsMerchantAndFilterReplay(t *testing.T) {
	t.Parallel()
	service := &Service{cursorSecret: []byte("test-cursor-secret-that-is-at-least-32-bytes")}
	period := Period{PeriodID: "jm-1405-03"}
	minimum := int64(1000)
	filter := DetailFilter{View: "ALL", TerminalID: "T318", Status: "Verified", MinAmountRial: &minimum, Limit: 25}
	createdAt := time.Date(2026, time.June, 20, 8, 30, 0, 0, time.UTC)

	cursor, err := service.encodeDetailCursor(42, period, filter, createdAt, 99)
	if err != nil {
		t.Fatal(err)
	}
	position, err := service.decodeDetailCursor(42, period, filter, cursor)
	if err != nil {
		t.Fatalf("decodeDetailCursor() error = %v", err)
	}
	if !position.CreatedAt.Equal(createdAt) || position.SessionID != 99 {
		t.Fatalf("decodeDetailCursor() = %+v", position)
	}

	if _, err := service.decodeDetailCursor(43, period, filter, cursor); !errors.Is(err, ErrInvalidCursor) {
		t.Fatalf("merchant replay error = %v, want ErrInvalidCursor", err)
	}
	changed := filter
	changed.Status = "Paid"
	if _, err := service.decodeDetailCursor(42, period, changed, cursor); !errors.Is(err, ErrInvalidCursor) {
		t.Fatalf("filter replay error = %v, want ErrInvalidCursor", err)
	}
}

func TestDetailCursorRejectsTampering(t *testing.T) {
	t.Parallel()
	service := &Service{cursorSecret: []byte("test-cursor-secret-that-is-at-least-32-bytes")}
	period := Period{PeriodID: "jm-1405-03"}
	filter := DetailFilter{View: "ALL", Limit: 25}
	cursor, err := service.encodeDetailCursor(42, period, filter, time.Now().UTC(), 99)
	if err != nil {
		t.Fatal(err)
	}
	sealed, err := base64.RawURLEncoding.DecodeString(cursor)
	if err != nil {
		t.Fatal(err)
	}
	sealed[len(sealed)-1] ^= 1
	tampered := base64.RawURLEncoding.EncodeToString(sealed)
	if _, err := service.decodeDetailCursor(42, period, filter, tampered); !errors.Is(err, ErrInvalidCursor) {
		t.Fatalf("tampered cursor error = %v, want ErrInvalidCursor", err)
	}
}