package pipeline

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"net/http"
)

// exchSuffix mappe le code bourse OpenFIGI vers le suffixe Yahoo Finance
var exchSuffix = map[string]string{
	"FP": ".PA", // Euronext Paris
	"GY": ".DE", // Xetra
	"LN": ".L",  // London
	"SM": ".MC", // Madrid
	"IM": ".MI", // Milan
	"NA": ".AS", // Amsterdam
	"BB": ".BR", // Bruxelles
	"UN": "",    // NYSE
	"UQ": "",    // NASDAQ
	"UW": "",    // NASDAQ (alt)
}

type openFIGIRequest struct {
	IDType  string `json:"idType"`
	IDValue string `json:"idValue"`
}

type openFIGIData struct {
	Ticker   string `json:"ticker"`
	ExchCode string `json:"exchCode"`
	Name     string `json:"name"`
}

type openFIGIResult struct {
	Data  []openFIGIData `json:"data"`
	Error string         `json:"error"`
}

// ResolveISIN résout un ISIN en ticker Yahoo Finance via OpenFIGI.
func ResolveISIN(ctx context.Context, apiKey, isin string) (string, error) {
	body, _ := json.Marshal([]openFIGIRequest{{IDType: "ID_ISIN", IDValue: isin}})

	req, err := http.NewRequestWithContext(ctx, http.MethodPost,
		"https://api.openfigi.com/v3/mapping", bytes.NewReader(body))
	if err != nil {
		return "", err
	}
	req.Header.Set("Content-Type", "application/json")
	if apiKey != "" {
		req.Header.Set("X-OPENFIGI-APIKEY", apiKey)
	}

	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()

	var results []openFIGIResult
	if err := json.NewDecoder(resp.Body).Decode(&results); err != nil {
		return "", fmt.Errorf("decode openfigi response: %w", err)
	}
	if len(results) == 0 || len(results[0].Data) == 0 {
		return "", fmt.Errorf("no result for ISIN %s", isin)
	}
	if results[0].Error != "" {
		return "", fmt.Errorf("openfigi error: %s", results[0].Error)
	}

	d := results[0].Data[0]
	suffix := exchSuffix[d.ExchCode]
	return d.Ticker + suffix, nil
}