package extractor

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

	"github.com/playwright-community/playwright-go"
)

type playWrightBrowser struct {
	browser   playwright.Browser
	ctx       playwright.BrowserContext
	userAgent string
	timeout   time.Duration
	cookieJar CookieJar
}

var _ Browser = playWrightBrowser{}

type PlayWrightBrowserSelection string

var (
	ErrInvalidBrowserSelection = errors.New("invalid browser selection")
	ErrInvalidStatusCode       = errors.New("invalid status code")
)

const (
	PlayWrightBrowserSelectionChromium PlayWrightBrowserSelection = "chromium"
	PlayWrightBrowserSelectionFirefox  PlayWrightBrowserSelection = "firefox"
	PlayWrightBrowserSelectionWebKit   PlayWrightBrowserSelection = "webkit"
)

type PlayWrightBrowserOptions struct {
	UserAgent string                     // If empty, defaults to "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.3"
	Browser   PlayWrightBrowserSelection // If unset defaults to Firefox.
	Timeout   *time.Duration             // If unset defaults to 30 seconds timeout.  If set to 0, no timeout

	// CookieJar will, if set, load all cookies from the cookie jar into the browser and save all cookies from the
	// browser into the cookie jar for each request.
	CookieJar
}

func cookieToPlaywrightOptionalCookie(cookie Cookie) playwright.OptionalCookie {
	return playwright.OptionalCookie{
		Name:     cookie.Name,
		Value:    cookie.Value,
		Domain:   playwright.String(cookie.Domain),
		Path:     playwright.String(cookie.Path),
		Expires:  playwright.Float(float64(cookie.Expires.Unix())),
		HttpOnly: playwright.Bool(cookie.HttpOnly),
	}
}

func playwrightCookieToCookie(cookie playwright.Cookie) Cookie {
	return Cookie{
		Name:     cookie.Name,
		Value:    cookie.Value,
		Domain:   cookie.Domain,
		Path:     cookie.Path,
		Expires:  time.Unix(int64(cookie.Expires), 0),
		HttpOnly: cookie.HttpOnly,
	}
}

func NewPlayWrightBrowser(opts ...PlayWrightBrowserOptions) (Browser, error) {
	var thirtySeconds = 30 * time.Second
	opt := PlayWrightBrowserOptions{
		UserAgent: "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.3",
		Browser:   PlayWrightBrowserSelectionFirefox,
		Timeout:   &thirtySeconds,
	}

	for _, o := range opts {
		if o.UserAgent != "" {
			opt.UserAgent = o.UserAgent
		}
		if o.Browser != "" {
			opt.Browser = o.Browser
		}
		if o.Timeout != nil {
			opt.Timeout = o.Timeout
		}
		if o.CookieJar != nil {
			opt.CookieJar = o.CookieJar
		}
	}

	err := playwright.Install()
	if err != nil {
		return nil, err
	}

	pw, err := playwright.Run()
	if err != nil {
		return nil, err
	}

	var bt playwright.BrowserType

	switch opt.Browser {
	case PlayWrightBrowserSelectionChromium:
		bt = pw.Chromium

	case PlayWrightBrowserSelectionFirefox:
		bt = pw.Firefox

	case PlayWrightBrowserSelectionWebKit:
		bt = pw.WebKit

	default:
		return nil, ErrInvalidBrowserSelection
	}

	browser, err := bt.Launch(playwright.BrowserTypeLaunchOptions{
		Headless: playwright.Bool(true),
	})
	if err != nil {
		return nil, err
	}

	c, err := browser.NewContext(playwright.BrowserNewContextOptions{
		UserAgent: playwright.String(opt.UserAgent),
	})
	if err != nil {
		return nil, err
	}

	if opt.CookieJar != nil {
		cookies, err := opt.CookieJar.GetAll()
		if err != nil {
			return nil, fmt.Errorf("error getting cookies from cookie jar: %w", err)
		}

		pwCookies := make([]playwright.OptionalCookie, len(cookies))

		for i, cookie := range cookies {
			pwCookies[i] = cookieToPlaywrightOptionalCookie(cookie)
		}

		err = c.AddCookies(pwCookies)

		if err != nil {
			return nil, fmt.Errorf("error adding cookies to browser: %w", err)
		}
	}

	return playWrightBrowser{
		browser:   browser,
		userAgent: opt.UserAgent,
		timeout:   *opt.Timeout,
		cookieJar: opt.CookieJar,
		ctx:       c,
	}, nil
}

func (b playWrightBrowser) updateCookies(_ context.Context, page playwright.Page) error {
	if b.cookieJar != nil {
		cookies, err := page.Context().Cookies(page.URL())

		for _, cookie := range cookies {
			// TODO: add support for deleting cookies from the jar which are deleted in the browser
			err = b.cookieJar.Set(playwrightCookieToCookie(cookie))

			if err != nil {
				return fmt.Errorf("error setting cookie in cookie jar: %w", err)
			}
		}
	}

	return nil
}

func (b playWrightBrowser) openPage(_ context.Context, target string) (playwright.Page, error) {
	page, err := b.ctx.NewPage()
	if err != nil {
		return nil, err
	}

	opts := playwright.PageGotoOptions{
		WaitUntil: playwright.WaitUntilStateLoad,
	}

	if b.timeout > 0 {
		var ms = float64(b.timeout.Milliseconds())
		opts.Timeout = &ms
	}
	resp, err := page.Goto(target, opts)
	if err != nil {
		return nil, err
	}

	slog.Info("opened page", "url", target, "status", resp.Status(), "request", resp.Request())

	if resp.Status() != 200 {
		slog.Info("invalid status code", "status", resp.Status(), "request", resp.Request())
		return nil, fmt.Errorf("%w: %d", ErrInvalidStatusCode, resp.Status())
	}

	return page, nil
}

func (b playWrightBrowser) Open(ctx context.Context, url string) (Source, error) {

	page, err := b.openPage(ctx, url)
	if err != nil {
		return nil, err
	}
	defer page.Close()

	text, err := page.Content()
	if err != nil {
		return nil, err
	}

	err = b.updateCookies(ctx, page)
	if err != nil {
		return nil, err
	}

	return source{
		sourceUrl: url,
		content:   text,
	}, nil
}

func (b playWrightBrowser) getScreenshot(_ context.Context, page playwright.Page, opts ScreenshotOptions) ([]byte, error) {
	var pwOpts playwright.PageScreenshotOptions

	if opts.Style == "" {
		opts.Style = ScreenshotStyleFullPage
	}

	if opts.Style == ScreenshotStyleFullPage {
		pwOpts.FullPage = playwright.Bool(true)
	} else if opts.Style == ScreenshotStyleViewport {
		pwOpts.FullPage = playwright.Bool(false)

		if opts.Width > 0 || opts.Height > 0 {
			pwOpts.Clip = &playwright.Rect{
				Width:  float64(opts.Width),
				Height: float64(opts.Height),
			}
		}
	}

	return page.Screenshot(pwOpts)
}

func (b playWrightBrowser) Screenshot(ctx context.Context, url string, opts ScreenshotOptions) ([]byte, error) {
	page, err := b.openPage(ctx, url)
	if err != nil {
		return nil, err
	}
	defer page.Close()

	err = b.updateCookies(ctx, page)
	if err != nil {
		return nil, err
	}

	return b.getScreenshot(ctx, page, opts)
}

func (b playWrightBrowser) OpenAndScreenshot(ctx context.Context, url string, opts ScreenshotOptions) (Source, []byte, error) {
	page, err := b.openPage(ctx, url)
	if err != nil {
		return nil, nil, err
	}
	defer page.Close()

	text, err := page.Content()
	if err != nil {
		return nil, nil, err
	}

	screenshot, err := b.getScreenshot(ctx, page, opts)
	if err != nil {
		return nil, nil, err
	}

	err = b.updateCookies(ctx, page)
	if err != nil {
		return nil, nil, err
	}

	return source{
		sourceUrl: url,
		content:   text,
	}, screenshot, nil
}

func (b playWrightBrowser) Close() error {
	return errors.Join(
		b.ctx.Close(),
		b.browser.Close(),
	)
}