package extractor

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

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

type playWrightBrowser struct {
	pw        *playwright.Playwright
	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")
	ErrPageNotFound            = errors.New("page not found")
	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; rv:133.0) Gecko/20100101 Firefox/133.0"
	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

	ShowBrowser bool // If false, browser will be headless
}

func cookieToPlaywrightOptionalCookie(cookie Cookie) playwright.OptionalCookie {
	return playwright.OptionalCookie{
		Name:     cookie.Name,
		Value:    cookie.Value,
		Domain:   playwright.String(cookie.Host),
		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,
		Host:     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; rv:133.0) Gecko/20100101 Firefox/133.0",
		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
		}
		opt.ShowBrowser = o.ShowBrowser
	}

	pw, err := playwright.Run()

	if err != nil {
		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(!opt.ShowBrowser),
	})
	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{
		pw:        pw,
		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, opts OpenPageOptions) (playwright.Page, error) {
	page, err := b.ctx.NewPage()
	if err != nil {
		return nil, err
	}

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

	if b.timeout > 0 {
		var ms = float64(b.timeout.Milliseconds())
		pwOpts.Timeout = &ms
	}

	if opts.Referer != "" {
		pwOpts.Referer = playwright.String(opts.Referer)
	}

	resp, err := page.Goto(target, pwOpts)
	if err != nil {
		return nil, err
	}

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

	if resp.Status() != 200 {
		time.Sleep(999 * time.Hour * 24)
		time.Sleep(25 * time.Second)

		_ = page.Close()

		if resp.Status() == 404 {
			return nil, ErrPageNotFound
		}
		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, opts OpenPageOptions) (Document, error) {

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

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

	return newDocument(b.pw, b.browser, page)
}

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

func deferClose(cl io.Closer) {
	_ = cl.Close()
}

func Screenshot(ctx context.Context, target string, timeout time.Duration) ([]byte, error) {
	browser, err := NewPlayWrightBrowser(PlayWrightBrowserOptions{
		Timeout: &timeout,
	})

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

	defer deferClose(browser)

	doc, err := browser.Open(ctx, target, OpenPageOptions{})
	if err != nil {
		return nil, fmt.Errorf("error opening page: %w", err)
	}

	defer deferClose(doc)

	return doc.Screenshot()
}