package browser

import (
	"context"
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"time"

	"github.com/chromedp/cdproto/network"
	"github.com/chromedp/chromedp"

	"git.davoryn.de/calic/claude-statusline/internal/config"
)

// FetchViaChrome navigates to a URL using Chrome with the persistent browser
// profile (which has Cloudflare clearance cookies) and returns the response
// body. Uses non-headless mode with a minimized/hidden window to avoid
// Cloudflare's headless detection, which causes infinite challenge loops.
func FetchViaChrome(url string) ([]byte, error) {
	profileDir := filepath.Join(config.ConfigDir(), "browser-profile")
	if err := os.MkdirAll(profileDir, 0o755); err != nil {
		return nil, fmt.Errorf("create browser profile dir: %w", err)
	}

	// Remove stale lock file from unclean shutdown
	_ = os.Remove(filepath.Join(profileDir, "SingletonLock"))

	execPath := findBrowserExec()

	// Use non-headless mode: Cloudflare detects headless Chrome and loops
	// the JS challenge forever. A real (but hidden) browser window passes.
	opts := append(chromedp.DefaultExecAllocatorOptions[:],
		chromedp.Flag("headless", false),
		chromedp.Flag("window-position", "-32000,-32000"), // off-screen
		chromedp.Flag("window-size", "1,1"),
		chromedp.Flag("disable-gpu", true),
		chromedp.Flag("no-first-run", true),
		chromedp.Flag("disable-extensions", true),
		chromedp.UserDataDir(profileDir),
	)
	if execPath != "" {
		opts = append(opts, chromedp.ExecPath(execPath))
	}

	allocCtx, allocCancel := chromedp.NewExecAllocator(context.Background(), opts...)
	defer allocCancel()

	ctx, cancel := chromedp.NewContext(allocCtx)
	defer cancel()

	// Total timeout for the operation
	ctx, timeoutCancel := context.WithTimeout(ctx, 30*time.Second)
	defer timeoutCancel()

	// Navigate and wait for Cloudflare challenge to resolve.
	// Poll the page content until we get valid JSON (not the challenge page).
	if err := chromedp.Run(ctx, chromedp.Navigate(url)); err != nil {
		return nil, fmt.Errorf("chromedp navigate: %w", err)
	}

	// Poll for JSON response — Cloudflare challenge takes a few seconds to clear
	ticker := time.NewTicker(1 * time.Second)
	defer ticker.Stop()

	for {
		select {
		case <-ctx.Done():
			return nil, fmt.Errorf("chromedp fetch timed out waiting for JSON response")
		case <-ticker.C:
			var body string
			// Try <pre> first (Chrome wraps JSON in <pre> tags)
			err := chromedp.Run(ctx,
				chromedp.Text("pre", &body, chromedp.ByQuery),
			)
			if err != nil || body == "" {
				// Fallback: try body directly
				_ = chromedp.Run(ctx,
					chromedp.Text("body", &body, chromedp.ByQuery),
				)
			}
			body = strings.TrimSpace(body)
			if body == "" {
				continue
			}
			// Check if we got actual JSON (starts with [ or {), not a challenge page
			if body[0] == '[' || body[0] == '{' {
				// Also extract any fresh cookies for future plain HTTP attempts
				_ = extractAndSaveCookies(ctx)
				cancel() // graceful close, flushes cookies to profile
				return []byte(body), nil
			}
		}
	}
}

// extractAndSaveCookies saves cf_clearance and other Cloudflare cookies
// alongside the session key, so plain HTTP requests can try them next time.
func extractAndSaveCookies(ctx context.Context) error {
	cookies, err := network.GetCookies().Do(ctx)
	if err != nil {
		return err
	}

	var parts []string
	for _, c := range cookies {
		if c.Domain == ".claude.ai" || c.Domain == "claude.ai" {
			if c.Name == "cf_clearance" || c.Name == "__cf_bm" || c.Name == "_cfuvid" {
				parts = append(parts, c.Name+"="+c.Value)
			}
		}
	}

	if len(parts) == 0 {
		return nil
	}

	// Write Cloudflare cookies to a file the fetcher can read
	cfPath := filepath.Join(config.ConfigDir(), "cf-cookies")
	return os.WriteFile(cfPath, []byte(strings.Join(parts, "\n")+"\n"), 0o600)
}