package pipeline

import (
	"context"
	"fmt"
	"log/slog"
	"time"

	"git.g3e.fr/H6N/account/internal/store"
)

type Config struct {
	OpenFIGIKey   string
	CoinGeckoKey  string
}

type Pipeline struct {
	store  *store.Store
	cfg    Config
	logger *slog.Logger
}

func New(s *store.Store, cfg Config, logger *slog.Logger) *Pipeline {
	return &Pipeline{store: s, cfg: cfg, logger: logger}
}

// FetchAll récupère les prix de tous les instruments et les écrit dans price_history.
func (p *Pipeline) FetchAll(ctx context.Context) error {
	instruments, err := p.store.ListInstruments(ctx)
	if err != nil {
		return err
	}

	now := time.Now().UTC()

	// Séparer les instruments par type pour batch CoinGecko
	var cryptoIDs []string
	cryptoByID := make(map[string]store.Instrument)

	for _, inst := range instruments {
		switch inst.Type {
		case "devise":
			if err := p.store.UpsertPrice(ctx, inst.ID, now, 1.0); err != nil {
				p.logger.Error("upsert devise price", "code", inst.Code, "error", err)
			}

		case "action", "etf":
			ticker, err := p.resolveTicker(ctx, inst)
			if err != nil {
				p.logger.Warn("could not resolve ticker", "instrument", inst.Code, "error", err)
				continue
			}
			price, err := FetchYahooPrice(ctx, ticker)
			if err != nil {
				p.logger.Warn("yahoo fetch failed", "ticker", ticker, "error", err)
				continue
			}
			if err := p.store.UpsertPrice(ctx, inst.ID, now, price); err != nil {
				p.logger.Error("upsert price", "instrument", inst.Code, "error", err)
			}
			p.logger.Info("price fetched", "instrument", inst.Code, "ticker", ticker, "price", price)

		case "crypto":
			coinID, err := p.resolveCoinID(ctx, inst)
			if err != nil {
				p.logger.Warn("could not resolve coingecko id", "instrument", inst.Code, "error", err)
				continue
			}
			cryptoIDs = append(cryptoIDs, coinID)
			cryptoByID[coinID] = inst
		}
	}

	// Batch fetch crypto
	if len(cryptoIDs) > 0 {
		prices, err := FetchCoinGeckoPrices(ctx, p.cfg.CoinGeckoKey, cryptoIDs)
		if err != nil {
			p.logger.Error("coingecko fetch failed", "error", err)
		} else {
			for coinID, price := range prices {
				inst := cryptoByID[coinID]
				if err := p.store.UpsertPrice(ctx, inst.ID, now, price); err != nil {
					p.logger.Error("upsert crypto price", "instrument", inst.Code, "error", err)
					continue
				}
				p.logger.Info("price fetched", "instrument", inst.Code, "coin_id", coinID, "price", price)
			}
		}
	}

	return nil
}

// BackfillInstrument récupère l'historique de prix d'un instrument entre from et to
// et upserte chaque point dans price_history. Idempotent.
func (p *Pipeline) BackfillInstrument(ctx context.Context, instrumentID int32, from, to time.Time) error {
	inst, err := p.store.GetInstrument(ctx, instrumentID)
	if err != nil {
		return fmt.Errorf("get instrument %d: %w", instrumentID, err)
	}

	switch inst.Type {
	case "devise":
		return nil // EUR toujours = 1, pas de backfill nécessaire

	case "action", "etf":
		ticker, err := p.resolveTicker(ctx, inst)
		if err != nil {
			return fmt.Errorf("resolve ticker for %s: %w", inst.Code, err)
		}
		points, err := FetchYahooHistory(ctx, ticker, from, to)
		if err != nil {
			return fmt.Errorf("yahoo history %s: %w", ticker, err)
		}
		for _, pt := range points {
			if err := p.store.UpsertPrice(ctx, inst.ID, pt.At, pt.Price); err != nil {
				p.logger.Error("upsert historical price", "instrument", inst.Code, "date", pt.At, "error", err)
			}
		}
		p.logger.Info("backfill done", "instrument", inst.Code, "points", len(points))

	case "crypto":
		coinID, err := p.resolveCoinID(ctx, inst)
		if err != nil {
			return fmt.Errorf("resolve coin id for %s: %w", inst.Code, err)
		}
		points, err := FetchCoinGeckoHistory(ctx, p.cfg.CoinGeckoKey, coinID, from, to)
		if err != nil {
			return fmt.Errorf("coingecko history %s: %w", coinID, err)
		}
		for _, pt := range points {
			if err := p.store.UpsertPrice(ctx, inst.ID, pt.At, pt.Price); err != nil {
				p.logger.Error("upsert historical price", "instrument", inst.Code, "date", pt.At, "error", err)
			}
		}
		p.logger.Info("backfill done", "instrument", inst.Code, "points", len(points))
	}

	return nil
}

// CleanHistory supprime les prix intraday des jours passés, ne gardant que le dernier par instrument.
func (p *Pipeline) CleanHistory(ctx context.Context) error {
	if err := p.store.CleanPastDays(ctx); err != nil {
		p.logger.Error("clean price history failed", "error", err)
		return err
	}
	p.logger.Info("price history cleaned")
	return nil
}

// resolveTicker retourne le ticker Yahoo Finance, en le résolvant via OpenFIGI si nécessaire.
func (p *Pipeline) resolveTicker(ctx context.Context, inst store.Instrument) (string, error) {
	ticker, err := p.store.GetTicker(ctx, inst.ID)
	if err == nil {
		return ticker, nil
	}

	resolved, err := ResolveISIN(ctx, p.cfg.OpenFIGIKey, inst.Code)
	if err != nil {
		return "", err
	}

	_ = p.store.UpsertTicker(ctx, inst.ID, resolved)
	return resolved, nil
}

// resolveCoinID retourne l'ID CoinGecko, en le résolvant via l'API search si nécessaire.
func (p *Pipeline) resolveCoinID(ctx context.Context, inst store.Instrument) (string, error) {
	coinID, err := p.store.GetTicker(ctx, inst.ID)
	if err == nil {
		return coinID, nil
	}

	resolved, err := ResolveCryptoID(ctx, p.cfg.CoinGeckoKey, inst.Code)
	if err != nil {
		return "", err
	}

	_ = p.store.UpsertTicker(ctx, inst.ID, resolved)
	return resolved, nil
}