package logic

import (
	"fmt"
	"strings"
	"unicode"
)

var exchangeAlias = map[string]string{
	"SSE": "SH", "SHSE": "SH", "XSHG": "SH",
	"SZSE": "SZ", "XSHE": "SZ",
	"BSE": "BJ", "BJSE": "BJ",
}

func stockCodeFromMap(item map[string]string) string {
	code := strings.ToUpper(strings.TrimSpace(mapGet(item, "m_strInstrumentID", "StockCode", "stock_code", "code")))
	ex := mapGet(item, "m_strExchangeID", "exchange", "exchange_id")
	return normalizeCode(code, ex)
}

func normalizeCode(code, exchange string) string {
	code = strings.ToUpper(strings.TrimSpace(code))
	if code == "" {
		return ""
	}
	if i := strings.LastIndex(code, "."); i >= 0 {
		symbol, ex := code[:i], code[i+1:]
		ex = canonExchange(ex)
		if ex == "SH" || ex == "SZ" || ex == "BJ" {
			return symbol + "." + ex
		}
		return ""
	}
	ex := canonExchange(exchange)
	if ex == "" && looksDigits(code, 6) {
		switch {
		case strings.HasPrefix(code, "92") || code[0] == '4' || code[0] == '8':
			ex = "BJ"
		case code[0] == '5' || code[0] == '6' || code[0] == '9' || strings.HasPrefix(code, "11"):
			ex = "SH"
		case code[0] == '0' || code[0] == '1' || code[0] == '2' || code[0] == '3':
			ex = "SZ"
		}
	}
	if ex == "SH" || ex == "SZ" || ex == "BJ" {
		return code + "." + ex
	}
	return ""
}

func canonExchange(ex string) string {
	ex = strings.ToUpper(strings.TrimSpace(ex))
	if v, ok := exchangeAlias[ex]; ok {
		return v
	}
	return ex
}

func looksDigits(s string, n int) bool {
	if len(s) != n {
		return false
	}
	for _, r := range s {
		if !unicode.IsDigit(r) {
			return false
		}
	}
	return true
}

func mapGet(item map[string]string, names ...string) string {
	for _, name := range names {
		if v := strings.TrimSpace(item[name]); v != "" {
			return v
		}
	}
	return ""
}

func asIntS(s string) int {
	s = strings.TrimSpace(s)
	if s == "" {
		return 0
	}
	var n int
	_, _ = fmt.Sscanf(s, "%d", &n)
	if n == 0 {
		var f float64
		if _, err := fmt.Sscanf(s, "%f", &f); err == nil {
			return int(f)
		}
	}
	return n
}