import os
import sys
import sublime

# Add the package archive path itself to sys.path
package_path = os.path.dirname(__file__)
if package_path not in sys.path:
    sys.path.insert(0, package_path)

# --- Add lib to sys.path ---
# Get the directory containing this file (MarkdownLivePreview.py)
plugin_dir = os.path.dirname(__file__)
# Construct the absolute path to the 'lib' directory
lib_path = os.path.join(plugin_dir, 'lib')
# Add it to the beginning of sys.path if it's not already there
if lib_path not in sys.path:
    sys.path.insert(0, lib_path)
# --- End sys.path modification ---

"""
Terminology
original_view: the view in the regular editor, without it's own window
markdown_view: the markdown view, in the special window
preview_view: the preview view, in the special window
original_window: the regular window
preview_window: the window with the markdown file and the preview
"""

import time
import struct
import sublime_plugin

from functools import partial

from .markdown2html import markdown2html

MARKDOWN_VIEW_INFOS = "markdown_view_infos"
PREVIEW_VIEW_INFOS = "preview_view_infos"
SETTING_DELAY_BETWEEN_UPDATES = "delay_between_updates"
SETTING_FONT_SCALE = "font_scale"

resources = {}


def plugin_loaded():
    global DELAY
    resources["base64_404_image"] = parse_image_resource(get_resource("404.base64"))
    resources["base64_loading_image"] = parse_image_resource(
        get_resource("loading.base64")
    )
    resources["stylesheet"] = get_resource("stylesheet.css")
    # FIXME: how could we make this setting update without restarting sublime text
    #        and not loading it every update as well
    DELAY = get_settings().get(SETTING_DELAY_BETWEEN_UPDATES, 100) # Provide default


class MdlpInsertCommand(sublime_plugin.TextCommand):
    def run(self, edit, point, string):
        self.view.insert(edit, point, string)


class OpenMarkdownPreviewCommand(sublime_plugin.TextCommand):
    def run(self, edit):

        print("--- MarkdownLivePreview: OpenMarkdownPreviewCommand running ---")
        """ If the file is saved exists on disk, we close it, and reopen it in a new
        window. Otherwise, we copy the content, erase it all (to close the file without
        a dialog) and re-insert it into a new view into a new window """

        original_view = self.view
        original_window_id = original_view.window().id()
        file_name = original_view.file_name()
        print("--- MarkdownLivePreview: Original view ID: {}, File: {}, Window ID: {} ---".format(original_view.id(), file_name, original_window_id))

        syntax_file = original_view.settings().get("syntax")

        # don't close the original view; keep it in your main window:
        # if file_name:
        #     original_view.close()
        # else:
        #     # the file isn't saved, we need to restore the content manually
        #     total_region = sublime.Region(0, original_view.size())
        #     content = original_view.substr(total_region)
        #     original_view.erase(edit, total_region)
        #     original_view.close()
        #     # FIXME: save the document to a temporary file, so that if we crash,
        #     #        the user doesn't lose what he wrote
        if not file_name:
            # If the file isn't saved, we still need the content for the new view
            total_region = sublime.Region(0, original_view.size())
            content = original_view.substr(total_region)
            print("--- MarkdownLivePreview: Unsaved file, content length: {} ---".format(len(content)))

        # instead of making a new window, grab your existing one:
        preview_window = original_view.window()
        print("--- MarkdownLivePreview: Using existing window ID: {} ---".format(preview_window.id()))

        preview_window.run_command(
            "set_layout",
            {
                "cols": [0.0, 0.5, 1.0],
                "rows": [0.0, 1.0],
                "cells": [[0, 0, 1, 1], [1, 0, 2, 1]],
            },
        )

        preview_window.focus_group(1)
        preview_view = preview_window.new_file()
        preview_view.set_scratch(True)
        preview_view.settings().set(PREVIEW_VIEW_INFOS, {})
        preview_view.set_name("Preview")
        print("--- MarkdownLivePreview: Created preview_view ID: {} ---".format(preview_view.id()))
        # FIXME: hide number lines on preview

        preview_window.focus_group(0)
        if file_name:
            markdown_view = preview_window.open_file(file_name)
            print("--- MarkdownLivePreview: Opened markdown_view ID: {} for file: {} ---".format(markdown_view.id(), file_name))
        else:
            markdown_view = preview_window.new_file()
            markdown_view.run_command("mdlp_insert", {"point": 0, "string": content})
            markdown_view.set_scratch(True)
            print("--- MarkdownLivePreview: Created new markdown_view ID: {} for unsaved content ---".format(markdown_view.id()))

        markdown_view.set_syntax_file(syntax_file)
        markdown_view.settings().set(
            MARKDOWN_VIEW_INFOS, {"original_window_id": original_window_id, "preview_view_id": preview_view.id(),},
        )
        infos_to_log = markdown_view.settings().get(MARKDOWN_VIEW_INFOS)
        print("--- MarkdownLivePreview: Stored infos on markdown_view {}: {} ---".format(markdown_view.id(), infos_to_log))

        # Manually trigger the initial setup and render via the listener
        # Use set_timeout_async to run it after the command finishes
        print("--- MarkdownLivePreview: Scheduling setup_and_update_preview for md_view: {}, pv_view: {} ---".format(markdown_view.id(), preview_view.id()))
        sublime.set_timeout_async(lambda: self.trigger_listener_setup(markdown_view.id(), preview_view.id()), 0)

    # Helper method to find and call the listener instance method
    # This is needed because the listener isn't easily accessible directly from the command instance
    def trigger_listener_setup(self, md_view_id, pv_view_id):
        print("--- MarkdownLivePreview: trigger_listener_setup running for md_view: {}, pv_view: {} ---".format(md_view_id, pv_view_id))
        # Access the listener instance directly via its class variable
        listener_instance = MarkdownLivePreviewListener.instance

        if listener_instance:
            print("--- MarkdownLivePreview: Found listener instance via class variable, calling setup_and_update_preview ---")
            listener_instance.setup_and_update_preview(md_view_id, pv_view_id)
        else:
            # This should ideally not happen if the listener loaded correctly before the command ran
            print("--- MarkdownLivePreview: ERROR: MarkdownLivePreviewListener.instance is None! Cannot trigger setup. ---")

    def is_enabled(self):
        # FIXME: is this the best way there is to check if the current syntax is markdown?
        #        should we only support default markdown?
        #        what about "md"?
        # FIXME: what about other languages, where markdown preview roughly works?
        return "markdown" in self.view.settings().get("syntax").lower()


class MarkdownLivePreviewListener(sublime_plugin.EventListener):
    instance = None # Class variable to hold the single instance

    phantom_sets = {
        # markdown_view.id(): phantom set
    }

    # we schedule an update for every key stroke, with a delay of DELAY
    # then, we update only if now() - last_update > DELAY
    last_update = 0

    def __init__(self):
        super().__init__() # Good practice to call super
        MarkdownLivePreviewListener.instance = self
        print("--- MarkdownLivePreview: Listener instance created and registered. ---")

    # FIXME: maybe we shouldn't restore the file in the original window...

    def on_pre_close(self, markdown_view):
        """ Close the view in the preview window, and store information for the on_close
        listener (see doc there)
        """
        if not markdown_view.settings().get(MARKDOWN_VIEW_INFOS):
            return

        self.markdown_view = markdown_view
        self.preview_window = markdown_view.window()
        self.file_name = markdown_view.file_name()

        if self.file_name is None:
            total_region = sublime.Region(0, markdown_view.size())
            self.content = markdown_view.substr(total_region)
        else:
            self.content = None

    def on_load_async(self, markdown_view):
        infos = markdown_view.settings().get(MARKDOWN_VIEW_INFOS)
        if not infos:
            # print("--- MarkdownLivePreview: on_load_async ignored for view {} - no infos ---".format(markdown_view.id())) # Optional: very verbose
            return

        print("--- MarkdownLivePreview: on_load_async triggered for markdown_view {} ---".format(markdown_view.id()))
        preview_view_id = infos.get("preview_view_id")
        if not preview_view_id:
            print("--- MarkdownLivePreview: ERROR in on_load_async: No preview_view_id found in infos: {} ---".format(infos))
            return # Should not happen if setup was correct

        preview_view = sublime.View(preview_view_id)
        if not preview_view.is_valid():
            print("--- MarkdownLivePreview: ERROR in on_load_async: Preview view {} is no longer valid ---".format(preview_view_id))
            return # Preview view was closed before loading finished

        print("--- MarkdownLivePreview: on_load_async found valid preview_view {} ---".format(preview_view.id()))
        # PhantomSet creation is now handled by setup_and_update_preview triggered from the command
        # self.phantom_sets[markdown_view.id()] = sublime.PhantomSet(preview_view)
        # print("--- MarkdownLivePreview: PhantomSet created in on_load_async for preview_view {} ---".format(preview_view.id())) # Keep log commented
        self._update_preview(markdown_view)

    def on_close(self, markdown_view):
        """ Use the information saved to restore the markdown_view as an original_view
        """
        infos = markdown_view.settings().get(MARKDOWN_VIEW_INFOS)
        if not infos:
            return

        if markdown_view.id() in self.phantom_sets:
            del self.phantom_sets[markdown_view.id()]

        # don't close the entire window—just let the user close the preview tab:
        # self.preview_window.run_command("close_window")

        # find the window with the right id
        original_window = next(
            window
            for window in sublime.windows()
            if window.id() == infos["original_window_id"]
        )
        if self.file_name:
            original_window.open_file(self.file_name)
        else:
            assert markdown_view.is_scratch(), (
                "markdown view of an unsaved file should " "be a scratch"
            )
            # note here that this is called original_view, because it's what semantically
            # makes sense, but this original_view.id() will be different than the one
            # that we closed first to reopen in the preview window
            # shouldn't cause any trouble though
            original_view = original_window.new_file()
            original_view.run_command(
                "mdlp_insert", {"point": 0, "string": self.content}
            )

            original_view.set_syntax_file(markdown_view.settings().get("syntax"))

    # here, views are NOT treated independently, which is theoretically wrong
    # but in practice, you can only edit one markdown file at a time, so it doesn't really
    # matter.
    # @min_time_between_call(.5)
    def on_modified_async(self, markdown_view):

        # print("--- MarkdownLivePreview: on_modified_async triggered for view {} ---".format(markdown_view.id())) # Optional: very verbose
        infos = markdown_view.settings().get(MARKDOWN_VIEW_INFOS)
        if not infos:
            return

        print("--- MarkdownLivePreview: Scheduling update for markdown_view {} ---".format(markdown_view.id()))
        # we schedule an update, which won't run if an
        sublime.set_timeout(partial(self._update_preview, markdown_view), DELAY)

    def _update_preview(self, markdown_view):
        print("--- MarkdownLivePreview: _update_preview called for markdown_view {} ---".format(markdown_view.id()))
        # if the buffer id is 0, that means that the markdown_view has been closed
        # This check is needed since a this function is used as a callback for when images
        # are loaded from the internet (ie. it could finish loading *after* the user
        # closes the markdown_view)
        # Reload settings each time to catch changes
        settings = get_settings()
        delay = settings.get(SETTING_DELAY_BETWEEN_UPDATES, 100) # Provide default
        font_scale = settings.get(SETTING_FONT_SCALE, 1.0) # Provide default
        print("--- MarkdownLivePreview: Using font_scale: {} ---".format(font_scale))

        if time.time() - self.last_update < delay / 1000:
            print("--- MarkdownLivePreview: Update skipped for view {} due to time delay ---".format(markdown_view.id()))
            return

        if markdown_view.buffer_id() == 0:
            print("--- MarkdownLivePreview: Update skipped for view {}: buffer_id is 0 (view closed) ---".format(markdown_view.id()))
            return

        # Check if the phantom set still exists for this view ID
        if markdown_view.id() not in self.phantom_sets:
            print("--- MarkdownLivePreview: Update skipped for view {}: No phantom set found ---".format(markdown_view.id()))
            # View might have been closed between modification and update
            return

        print("--- MarkdownLivePreview: Update proceeding for view {} ---".format(markdown_view.id()))
        self.last_update = time.time()

        total_region = sublime.Region(0, markdown_view.size())
        markdown = markdown_view.substr(total_region)
        print("--- MarkdownLivePreview: Read markdown content (length: {}) ---".format(len(markdown)))

        infos = markdown_view.settings().get(MARKDOWN_VIEW_INFOS)
        if not infos:
            print("--- MarkdownLivePreview: ERROR in _update_preview: No infos found for view {} ---".format(markdown_view.id()))
            return # Should not happen

        preview_view_id = infos.get("preview_view_id")
        if not preview_view_id:
            print("--- MarkdownLivePreview: ERROR in _update_preview: No preview_view_id found in infos: {} ---".format(infos))
            return # Should not happen

        preview_view = sublime.View(preview_view_id)
        if not preview_view.is_valid():
            print("--- MarkdownLivePreview: ERROR in _update_preview: Preview view {} is no longer valid ---".format(preview_view_id))
            return # Preview view was closed

        print("--- MarkdownLivePreview: Found valid preview_view {} for update ---".format(preview_view.id()))
        # Get viewport_width, default to a large value if view isn't ready
        viewport_extent = preview_view.viewport_extent()
        viewport_width = viewport_extent[0] if viewport_extent else 1024
        print("--- MarkdownLivePreview: Viewport width: {} ---".format(viewport_width))


        basepath = os.path.dirname(markdown_view.file_name()) if markdown_view.file_name() else '.' # Handle unsaved files
        print("--- MarkdownLivePreview: Calling markdown2html with basepath: {} ---".format(basepath))
        html = markdown2html(
            markdown,
            basepath,
            partial(self._update_preview, markdown_view),
            resources,
            viewport_width,
            font_scale,
        )

        # Truncate HTML safely for logging
        html_preview = html[:100].replace('\n', ' ') # Avoid breaking log lines
        print("--- MarkdownLivePreview: Generated HTML (starts with): {}... ---".format(html_preview))

        self.phantom_sets[markdown_view.id()].update(
            [
                sublime.Phantom(
                    sublime.Region(0),
                    html,
                    sublime.LAYOUT_BLOCK,
                    lambda href: sublime.run_command("open_url", {"url": href}),
                )
            ]
        )
        print("--- MarkdownLivePreview: Updated phantoms in preview_view {} ---".format(preview_view.id()))

    def setup_and_update_preview(self, markdown_view_id, preview_view_id):
        print("--- MarkdownLivePreview: setup_and_update_preview called for md_view: {}, pv_view: {} ---".format(markdown_view_id, preview_view_id))
        markdown_view = sublime.View(markdown_view_id)
        preview_view = sublime.View(preview_view_id)

        if not markdown_view.is_valid():
            print("--- MarkdownLivePreview: ERROR in setup_and_update: markdown_view {} is not valid ---".format(markdown_view_id))
            return
        if not preview_view.is_valid():
            print("--- MarkdownLivePreview: ERROR in setup_and_update: preview_view {} is not valid ---".format(preview_view_id))
            return

        # Create PhantomSet if it doesn't exist (shouldn't at this point)
        if markdown_view_id not in self.phantom_sets:
            print("--- MarkdownLivePreview: Creating PhantomSet for preview_view {} in setup ---".format(preview_view.id()))
            self.phantom_sets[markdown_view_id] = sublime.PhantomSet(preview_view)
        else:
            # This case might occur if the command is run multiple times rapidly? Ensure it's associated correctly.
            print("--- MarkdownLivePreview: Warning: PhantomSet already existed for markdown_view {} in setup. Re-associating with preview_view {}. ---".format(markdown_view_id, preview_view.id()))
            self.phantom_sets[markdown_view_id].view = preview_view # Ensure it points to the correct view

        # Trigger the first update
        print("--- MarkdownLivePreview: Triggering initial _update_preview from setup ---")
        self._update_preview(markdown_view)


def get_settings():
    return sublime.load_settings("MarkdownLivePreview.sublime-settings")


def get_resource(resource):
    package_name = __package__ # Get the current package name dynamically
    path = "Packages/{}/resources/{}".format(package_name, resource)
    # Original logic: check absolute path first (useful for unpacked development)
    # Adjusted abs_path to use dynamic package_name
    abs_path = os.path.join(sublime.packages_path(), package_name, "resources", resource)
    if os.path.isfile(abs_path):
        with open(abs_path, "r") as fp:
            return fp.read()
    # Fallback to sublime.load_resource (works for packed and unpacked)
    return sublime.load_resource(path)


def parse_image_resource(text):
    width, height, base64_image = text.splitlines()
    return base64_image, (int(width), int(height))


# try to reload the resources if we save this file
try:
    plugin_loaded()
except OSError:
    pass