package coingecko

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

	"gitea.stevedudenhoeffer.com/steve/go-extractor"
	"gitea.stevedudenhoeffer.com/steve/go-extractor/sites/internal/parse"
)

// CoinPrice holds structured cryptocurrency price data from CoinGecko.
type CoinPrice struct {
	Name      string
	Symbol    string
	Price     float64
	Change24h float64 // percentage
	Change7d  float64
	MarketCap float64
	Volume24h float64
	High24h   float64
	Low24h    float64
}

// Config holds configuration for the CoinGecko extractor.
type Config struct{}

// DefaultConfig is the default CoinGecko configuration.
var DefaultConfig = Config{}

func (c Config) validate() Config {
	return c
}

// coinURL returns the CoinGecko URL for a given coin ID (e.g. "bitcoin", "ethereum").
func coinURL(coin string) string {
	return fmt.Sprintf("https://www.coingecko.com/en/coins/%s", strings.ToLower(coin))
}

// GetPrice extracts structured cryptocurrency price data from CoinGecko.
func (c Config) GetPrice(ctx context.Context, b extractor.Browser, coin string) (*CoinPrice, error) {
	c = c.validate()

	u := coinURL(coin)

	slog.Info("fetching coin price", "url", u, "coin", coin)
	doc, err := b.Open(ctx, u, extractor.OpenPageOptions{})
	if err != nil {
		return nil, fmt.Errorf("failed to open coin page: %w", err)
	}
	defer extractor.DeferClose(doc)

	timeout := 10 * time.Second
	if err := doc.WaitForNetworkIdle(&timeout); err != nil {
		slog.Warn("WaitForNetworkIdle failed", "err", err)
	}

	return extractCoinPrice(doc)
}

// GetPrice is a convenience function using DefaultConfig.
func GetPrice(ctx context.Context, b extractor.Browser, coin string) (*CoinPrice, error) {
	return DefaultConfig.GetPrice(ctx, b, coin)
}

func extractCoinPrice(doc extractor.Node) (*CoinPrice, error) {
	var data CoinPrice

	// Coin name — typically in h1 on the coin page
	names := doc.Select("div[data-coin-show-target='coin'] h1")
	if len(names) == 0 {
		names = doc.Select("h1")
	}
	if len(names) > 0 {
		data.Name, _ = names[0].Text()
		data.Name = strings.TrimSpace(data.Name)
	}

	// Symbol — often shown as abbreviated ticker
	syms := doc.Select("span[data-coin-symbol]")
	if len(syms) > 0 {
		txt, _ := syms[0].Text()
		data.Symbol = strings.ToUpper(strings.TrimSpace(txt))
	}

	// Current price
	prices := doc.Select("span[data-converter-target='price']")
	if len(prices) == 0 {
		prices = doc.Select("span[data-price-target='price']")
	}
	if len(prices) > 0 {
		txt, _ := prices[0].Text()
		data.Price = parse.NumericOnly(txt)
	}

	// 24h change percentage
	changes24h := doc.Select("span[data-price-change='24h']")
	if len(changes24h) > 0 {
		txt, _ := changes24h[0].Text()
		val := parse.NumericOnly(txt)
		if strings.Contains(txt, "-") {
			val = -val
		}
		data.Change24h = val
	}

	// 7d change percentage
	changes7d := doc.Select("span[data-price-change='7d']")
	if len(changes7d) > 0 {
		txt, _ := changes7d[0].Text()
		val := parse.NumericOnly(txt)
		if strings.Contains(txt, "-") {
			val = -val
		}
		data.Change7d = val
	}

	// Market cap
	mcaps := doc.Select("span[data-coin-stat='market-cap']")
	if len(mcaps) > 0 {
		txt, _ := mcaps[0].Text()
		data.MarketCap = parseLargeNumber(txt)
	}

	// 24h volume
	vols := doc.Select("span[data-coin-stat='volume']")
	if len(vols) > 0 {
		txt, _ := vols[0].Text()
		data.Volume24h = parseLargeNumber(txt)
	}

	// 24h high
	highs := doc.Select("span[data-coin-stat='high-24h']")
	if len(highs) > 0 {
		txt, _ := highs[0].Text()
		data.High24h = parse.NumericOnly(txt)
	}

	// 24h low
	lows := doc.Select("span[data-coin-stat='low-24h']")
	if len(lows) > 0 {
		txt, _ := lows[0].Text()
		data.Low24h = parse.NumericOnly(txt)
	}

	return &data, nil
}

// parseLargeNumber handles values like "$1,234,567,890" or "$1.5T" or "$250B".
func parseLargeNumber(s string) float64 {
	s = strings.TrimSpace(s)
	upper := strings.ToUpper(s)

	numeric := parse.NumericOnly(s)

	if strings.HasSuffix(upper, "T") {
		return numeric * 1_000_000_000_000
	}
	if strings.HasSuffix(upper, "B") {
		return numeric * 1_000_000_000
	}
	if strings.HasSuffix(upper, "M") {
		return numeric * 1_000_000
	}

	return numeric
}