package controller

import (
	"math"
	"testing"

	"github.com/QuantumNous/new-api/common"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestGetDeepSeekBalanceUSD(t *testing.T) {
	tests := []struct {
		name            string
		responseJSON    string
		usdExchangeRate float64
		want            float64
		wantErrContains string
	}{
		{
			name:            "prefers USD when USD precedes CNY",
			responseJSON:    `{"balance_infos":[{"currency":"USD","total_balance":"12.50"},{"currency":"CNY","total_balance":"73.00"}]}`,
			usdExchangeRate: 7.3,
			want:            12.5,
		},
		{
			name:            "prefers USD when CNY precedes USD",
			responseJSON:    `{"balance_infos":[{"currency":"CNY","total_balance":"73.00"},{"currency":"USD","total_balance":"12.50"}]}`,
			usdExchangeRate: 7.3,
			want:            12.5,
		},
		{
			name:            "converts CNY when USD is absent",
			responseJSON:    `{"balance_infos":[{"currency":"CNY","total_balance":"73.00"}]}`,
			usdExchangeRate: 7.3,
			want:            10,
		},
		{
			name:            "returns error when USD and CNY are absent",
			responseJSON:    `{"balance_infos":[{"currency":"EUR","total_balance":"10.00"}]}`,
			usdExchangeRate: 7.3,
			wantErrContains: "currency USD or CNY not found",
		},
		{
			name:            "returns USD parse error instead of falling back to CNY",
			responseJSON:    `{"balance_infos":[{"currency":"USD","total_balance":"invalid"},{"currency":"CNY","total_balance":"73.00"}]}`,
			usdExchangeRate: 7.3,
			wantErrContains: "invalid syntax",
		},
		{
			name:            "rejects NaN USD balance",
			responseJSON:    `{"balance_infos":[{"currency":"USD","total_balance":"NaN"}]}`,
			usdExchangeRate: 7.3,
			wantErrContains: "USD balance must be finite",
		},
		{
			name:            "rejects negative USD balance",
			responseJSON:    `{"balance_infos":[{"currency":"USD","total_balance":"-1.00"}]}`,
			usdExchangeRate: 7.3,
			wantErrContains: "USD balance must be non-negative",
		},
		{
			name:            "rejects positive infinity CNY balance",
			responseJSON:    `{"balance_infos":[{"currency":"CNY","total_balance":"+Inf"}]}`,
			usdExchangeRate: 7.3,
			wantErrContains: "CNY balance must be finite",
		},
		{
			name:            "rejects negative CNY balance",
			responseJSON:    `{"balance_infos":[{"currency":"CNY","total_balance":"-7.30"}]}`,
			usdExchangeRate: 7.3,
			wantErrContains: "CNY balance must be non-negative",
		},
		{
			name:            "returns error for non-positive CNY exchange rate",
			responseJSON:    `{"balance_infos":[{"currency":"CNY","total_balance":"73.00"}]}`,
			usdExchangeRate: 0,
			wantErrContains: "USD exchange rate must be greater than zero",
		},
		{
			name:            "rejects NaN CNY exchange rate",
			responseJSON:    `{"balance_infos":[{"currency":"CNY","total_balance":"73.00"}]}`,
			usdExchangeRate: math.NaN(),
			wantErrContains: "USD exchange rate must be finite",
		},
		{
			name:            "rejects positive infinity CNY exchange rate",
			responseJSON:    `{"balance_infos":[{"currency":"CNY","total_balance":"73.00"}]}`,
			usdExchangeRate: math.Inf(1),
			wantErrContains: "USD exchange rate must be finite",
		},
		{
			name:            "rejects CNY conversion overflow",
			responseJSON:    `{"balance_infos":[{"currency":"CNY","total_balance":"1.7976931348623157e+308"}]}`,
			usdExchangeRate: math.SmallestNonzeroFloat64,
			wantErrContains: "converted USD balance must be finite",
		},
	}

	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			var response DeepSeekUsageResponse
			require.NoError(t, common.Unmarshal([]byte(test.responseJSON), &response))

			balance, err := getDeepSeekBalanceUSD(response, test.usdExchangeRate)
			if test.wantErrContains != "" {
				require.Error(t, err)
				assert.Contains(t, err.Error(), test.wantErrContains)
				return
			}

			require.NoError(t, err)
			assert.InDelta(t, test.want, balance, 1e-12)
		})
	}
}