package service

import (
	"testing"

	"github.com/shopspring/decimal"
	"github.com/wmms/wmms/internal/model"
)

// ClassifyStock 是库存状态的唯一判定入口，这张表同时钉住"新增物料不误报"和
// "真的低于阈值要报警"两侧的边界。它必须与 repository.stockWarningHavingSQL 一致。
func TestClassifyStockBoundaries(t *testing.T) {
	cases := []struct {
		name           string
		totalOnHand    string
		warningStock   string
		warningEnabled bool
		want           string
	}{
		// 阈值为 0 是合法配置，含义是"库存降到 0 时预警"，不再被排除在预警之外。
		{"阈值0启用且库存归零", "0", "0", true, model.StockStatusLow},
		{"阈值0启用但还剩一点", "0.000001", "0", true, model.StockStatusNormal},
		{"有货且阈值为0", "5", "0", true, model.StockStatusNormal},
		// 没配过规则和手动关闭预警由同一个 warningEnabled=false 表达，一律不报警。
		{"没配过预警规则", "0", "0", false, model.StockStatusNormal},
		{"设了阈值但库存归零", "0", "10", true, model.StockStatusLow},
		{"低于阈值", "5", "10", true, model.StockStatusLow},
		{"恰好触达阈值即预警", "10", "10", true, model.StockStatusLow},
		{"略高于阈值", "10.000001", "10", true, model.StockStatusNormal},
		{"高于阈值", "15", "10", true, model.StockStatusNormal},
		{"用完但手动关闭预警", "0", "10", false, model.StockStatusNormal},
		{"低于阈值但手动关闭预警", "5", "10", false, model.StockStatusNormal},
		{"有货且手动关闭预警", "15", "10", false, model.StockStatusNormal},
		// 数量是 decimal 字符串，按字典序比较会把 "370" 判成小于 "50"。
		{"大数按数值而非字典序比较", "370.000000", "50.000000", true, model.StockStatusNormal},
	}

	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			got := ClassifyStock(
				decimal.RequireFromString(tc.totalOnHand),
				decimal.RequireFromString(tc.warningStock),
				tc.warningEnabled,
			)
			if got != tc.want {
				t.Fatalf("ClassifyStock(%s, %s, %v) = %s, want %s",
					tc.totalOnHand, tc.warningStock, tc.warningEnabled, got, tc.want)
			}
		})
	}
}

func TestSignedChangeQuantityUsesTheSameConventionForInboundAndOutbound(t *testing.T) {
	quantity := decimal.NewFromInt(100)
	cases := []struct {
		logType string
		want    string
	}{
		{logType: "in", want: "100"},
		{logType: "out", want: "-100"},
	}

	for _, tc := range cases {
		t.Run(tc.logType, func(t *testing.T) {
			if got := signedChangeQuantity(tc.logType, quantity); !got.Equal(decimal.RequireFromString(tc.want)) {
				t.Fatalf("signedChangeQuantity(%q, 100) = %s, want %s", tc.logType, got, tc.want)
			}
		})
	}
}