package browser

import (
	"context"
	"fmt"
	"log"
	"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 a dedicated browser
// profile and returns the response body. Uses stealth flags to avoid
// Cloudflare's automation detection (navigator.webdriver, etc.).
func FetchViaChrome(url string) ([]byte, error) {
	// Use a dedicated fetch profile separate from the login profile.
	profileDir := filepath.Join(config.ConfigDir(), "fetch-profile")
	if err := os.MkdirAll(profileDir, 0o755); err != nil {
		return nil, fmt.Errorf("create fetch profile dir: %w", err)
	}

	_ = os.Remove(filepath.Join(profileDir, "SingletonLock"))

	execPath := findBrowserExec()

	// Start with minimal options — NOT DefaultExecAllocatorOptions, which
	// includes flags that Cloudflare detects (--enable-automation, etc.).
	opts := []chromedp.ExecAllocatorOption{
		chromedp.NoFirstRun,
		chromedp.NoDefaultBrowserCheck,
		chromedp.UserDataDir(profileDir),

		// Stealth: disable automation indicators
		chromedp.Flag("disable-blink-features", "AutomationControlled"),
		chromedp.Flag("enable-automation", false),
		chromedp.Flag("disable-infobars", true),

		// Window: off-screen so it doesn't flash
		chromedp.Flag("window-position", "-32000,-32000"),
		chromedp.Flag("window-size", "1,1"),
		chromedp.Flag("disable-gpu", true),
		chromedp.Flag("disable-extensions", true),
		chromedp.Flag("no-first-run", true),

		// Use non-headless — Cloudflare detects headless mode
		chromedp.Flag("headless", false),
	}
	if execPath != "" {
		opts = append(opts, chromedp.ExecPath(execPath))
	}

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

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

	ctx, timeoutCancel := context.WithTimeout(ctx, 30*time.Second)
	defer timeoutCancel()

	// Inject the session key cookie before navigating
	sessionKey := config.GetSessionKey()
	if sessionKey != "" {
		err := chromedp.Run(ctx,
			chromedp.Navigate("about:blank"),
			setCookieAction("sessionKey", sessionKey, ".claude.ai"),
		)
		if err != nil {
			log.Printf("chrome-fetch: cookie injection failed: %v", err)
		}
	}

	// Patch navigator.webdriver to false via CDP
	err := chromedp.Run(ctx,
		chromedp.ActionFunc(func(ctx context.Context) error {
			_, _, _, err := chromedp.Targets(ctx)
			_ = err
			return nil
		}),
		chromedp.Evaluate(`Object.defineProperty(navigator, 'webdriver', {get: () => undefined})`, nil),
	)
	if err != nil {
		log.Printf("chrome-fetch: webdriver patch failed: %v", err)
	}

	log.Printf("chrome-fetch: navigating to %s (exec: %q)", url, execPath)
	if err := chromedp.Run(ctx, chromedp.Navigate(url)); err != nil {
		log.Printf("chrome-fetch: navigate failed: %v", err)
		return nil, fmt.Errorf("chromedp navigate: %w", err)
	}
	log.Printf("chrome-fetch: navigation complete, polling for JSON...")

	// Poll for JSON response — Cloudflare challenge takes a few seconds
	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
			err := chromedp.Run(ctx,
				chromedp.Text("pre", &body, chromedp.ByQuery),
			)
			if err != nil || body == "" {
				_ = chromedp.Run(ctx,
					chromedp.Text("body", &body, chromedp.ByQuery),
				)
			}
			body = strings.TrimSpace(body)
			if body == "" {
				log.Printf("chrome-fetch: page body empty, waiting...")
				continue
			}
			if body[0] == '[' || body[0] == '{' {
				log.Printf("chrome-fetch: got JSON response (%d bytes)", len(body))
				_ = extractAndSaveCookies(ctx)
				cancel()
				return []byte(body), nil
			}
			snippet := body
			if len(snippet) > 200 {
				snippet = snippet[:200]
			}
			log.Printf("chrome-fetch: non-JSON body (%d bytes): %s", len(body), snippet)
		}
	}
}

// setCookieAction sets a cookie via the DevTools protocol.
func setCookieAction(name, value, domain string) chromedp.Action {
	return chromedp.ActionFunc(func(ctx context.Context) error {
		expr := network.SetCookie(name, value).
			WithDomain(domain).
			WithPath("/").
			WithHTTPOnly(true).
			WithSecure(true)
		return expr.Do(ctx)
	})
}

// extractAndSaveCookies saves cf_clearance and other Cloudflare cookies
// so plain HTTP requests can try them on subsequent polls.
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
	}

	cfPath := filepath.Join(config.ConfigDir(), "cf-cookies")
	return os.WriteFile(cfPath, []byte(strings.Join(parts, "\n")+"\n"), 0o600)
}