<?php

namespace NoccyLabs\JEdit\Editor;

use NoccyLabs\JEdit\List\TreeList;
use NoccyLabs\JEdit\Terminal\Terminal;
use NoccyLabs\JEdit\Tree\ArrayNode;
use NoccyLabs\JEdit\Tree\ObjectNode;
use NoccyLabs\JEdit\Tree\Tree;
use NoccyLabs\JEdit\Tree\ValueNode;
use Symfony\Component\Yaml\Yaml;

class Editor
{

    private Tree $document;

    private TreeList $list;

    private int $currentRow = 0;

    private int $scrollOffset = 0;

    private ?string $filename = "untitled.json";

    private ?string $shortfilename = "untitled.json";

    public function __construct(private Terminal $term)
    {
        $this->document = new Tree();

        // $this->document->load((object)[
        //     'foo' => true,
        //     'bar' => [
        //         'a', 'b', 'c'
        //     ],
        //     'what' => 42
        // ]);

        $this->list = new TreeList($this->document);
    }

    public function loadFile(string $filename): void
    {
        $this->filename = $filename;
        $this->shortfilename = basename($filename);
        $ext = strtolower(pathinfo($filename, PATHINFO_EXTENSION));
        switch ($ext) {
            case 'json':
                $doc = json_decode(file_get_contents($filename));
                break;
            case 'yml':
            case 'yaml':
                $doc = Yaml::parseFile($filename);
                break;    
            default:
                throw new \RuntimeException("Unable to read file of type {$ext}");
        }
        $this->document->load($doc);
        $this->list->parseTree();
    }

    public function loadDocument(mixed $document): void
    {
        $this->document->load($document);
        $this->list->parseTree();
    }

    private bool $running = true;

    public function run()
    {
        $this->list->parseTree();
        $this->redrawEditor();

        while ($this->running) {
            [$w,$h] = $this->term->getSize();
            $read = $this->term->readKey();
            switch ($read) {
                case 'k{UP}':
                    $this->currentRow = max(0, $this->currentRow - 1);
                    $this->redrawEditor();
                    break;
                case 'k{DOWN}':
                    $this->currentRow = min(count($this->list), $this->currentRow + 1);
                    $this->redrawEditor();
                    break;
                case 'k{PGUP}':
                    $this->currentRow = max(0, $this->currentRow - ($h - 3));
                    $this->redrawEditor();
                    break;
                case 'k{PGDN}':
                    $this->currentRow = min(count($this->list), $this->currentRow + ($h - 3));
                    $this->redrawEditor();
                    break;

                case 'E':
                    //$coll = $this->list->findNearestCollection($this->currentRow);
                    $entry = $this->list->getEntryForIndex($this->currentRow);
                    $path = $this->list->getPathForIndex($this->currentRow);
                    $parentIndex = $this->list->getIndexForPath(dirname($path));
                    $parent = $this->list->getEntryForIndex($parentIndex);
                    
                    if ($parent->node instanceof ObjectNode) {
                        $newVal = $this->ask("\e[33;1mnew key:\e[0m ", $entry->key);
                        if ($newVal !== null) {
                            $entry->key = $newVal;
                            $this->redrawEditor();
                        }
                    } else {
                        $this->term->setCursor(1, $h);
                        echo "\e[97;41mCan only edit keys on objects\e[K\e[0m";
                    }
                    break;
    
                case 'e':
                    //$coll = $this->list->findNearestCollection($this->currentRow);
                    $node = $this->list->getNodeForIndex($this->currentRow);
                    if ($node instanceof ValueNode) {
                        $val = json_encode($node->value, JSON_UNESCAPED_SLASHES);
                        $newVal = $this->ask("\e[33;1mnew value:\e[0m ", $val);
                        if ($newVal !== null) {
                            $val = json_decode($newVal);
                            $node->value = $val;
                            $this->redrawEditor();
                        } else {
                            $this->redrawInfoBar();
                        }
                    } else {
                        $this->term->setCursor(1, $h);
                        echo "\e[97;41mCan not edit array/object\e[K\e[0m";
                    }
                    break;

                case '[':
                    break;                    

                case 'D':
                    $node = $this->list->getNodeForIndex($this->currentRow);
                    $path = $this->list->getPathForIndex($this->currentRow);
                    $parentPath = dirname($path);
                    $deleteKey = basename($path);
                    $collNode = $this->list->getNodeForPath($parentPath);
                    if ($collNode instanceof ArrayNode) {
                        $collNode->removeIndex($deleteKey);
                        $this->list->parseTree();
                        $this->redrawEditor();
                    } elseif ($collNode instanceof ObjectNode) {
                        $collNode->unset($deleteKey);
                        $this->list->parseTree();
                        $this->redrawEditor();
                    } else {
                        $this->term->setCursor(1, $h);
                        echo "\e[97;41mCan only delete from object, array\e[K\e[0m";
                    }
                    break;

                // FIXME make sure this clones; editing a clone updates original as well
                // case 'd':
                //     $node = $this->list->getNodeForIndex($this->currentRow);
                //     $coll = $this->list->findNearestCollection($this->currentRow, true);
                //     if (!$coll)
                //         break;
                //     $collNode = $this->list->getNodeForIndex($coll);
                //     if ($collNode instanceof ArrayNode) {
                //         $collNode->append(clone $node);
                //         $this->list->parseTree();
                //         $this->redrawEditor();
                //     } else {
                //         $this->term->setCursor(1, $h);
                //         echo "\e[97;41mCan only duplicate in arrays, node={$this->currentRow}, coll={$coll}\e[K\e[0m";
                //     }
                //     break;

                case 'i':
                    $coll = $this->list->findNearestCollection($this->currentRow);
                    $node = $this->list->getNodeForIndex($coll);
                    if ($node instanceof ObjectNode) {
                        $key = $this->ask("\e[97mkey:\e[0m ");
                        if ($key === null) {
                            $this->redrawInfoBar();
                            break;
                        }
                    }

                    $value = $this->ask("\e[97mvalue:\e[0m ");
                    if ($value !== null) {
                        $value = json_decode($value);
                        $valueNode = match (true) {
                            is_array($value) => new ArrayNode([]),
                            is_object($value) => new ObjectNode([]),
                            default => new ValueNode($value)
                        };
                        if ($node instanceof ArrayNode) {
                            $node->append($valueNode);
                        } elseif ($node instanceof ObjectNode) {
                            $node->set($key, $valueNode);
                        }
                        $this->list->parseTree();
                        $this->redrawEditor();
                    } else {
                        $this->redrawInfoBar();
                    }
                    break;

                case 'Q':
                case "\x03":
                    $this->running = false;
                    break;

                case null:
                    break;
                default:
                    $this->term->setCursor(1, $h, true);
                    echo $read; 
                    sleep(1);
            }
        }

        // for ($n = 0; $n < 20; $n++) {
        //     $this->currentRow = $n;
        //     $this->redrawEditor();
        //     sleep(1);
        // }

    }

    public function ask(string $prompt, $value = ''): ?string
    {
        $plainPrompt = preg_replace('<\e\[.+?m>', '', $prompt);
        $promptLen = mb_strlen($plainPrompt);
        [$w,$h] = $this->term->getSize();

        $prompting = true;
        $cursorPos = mb_strlen($value);
        while ($prompting) {
            $this->term->setCursor(1, $h);
            echo $prompt."\e[0m\e[K".$value;
            $this->term->setCursor($promptLen+$cursorPos+1, $h, true);
            while (null === ($ch = $this->term->readKey())) {
                usleep(10000);
            }
            if (mb_strlen($ch) == 1) {
                if (ord($ch) < 32) {
                    if (ord($ch) == 13) {
                        $this->term->setCursor(1, $h);
                        echo "\e[0m\e[K";
                        return $value;
                    }
                    if (ord($ch) == 3) {
                        $this->term->setCursor(1, $h);
                        echo "\e[0m\e[K";
                        return null;
                    } 
                } elseif (ord($ch) == 127) {
                    if ($cursorPos > 0) {
                        $value = substr($value, 0, $cursorPos - 1) . substr($value, $cursorPos);
                        $cursorPos--;
                    }
                } else {
                    $value = mb_substr($value, 0, $cursorPos) . $ch . mb_substr($value, $cursorPos);
                    $cursorPos++;
                }
            } else {
                switch ($ch) {
                    case "k{LEFT}":
                        if ($cursorPos > 0)
                            $cursorPos--;
                        break;
                    case "k{RIGHT}":
                        if ($cursorPos < mb_strlen($value))
                            $cursorPos++;
                        break;
                }
            }
        }

    }

    public function redrawEditor()
    {
        [$w,$h] = $this->term->getSize();

        while ($this->currentRow < $this->scrollOffset) $this->scrollOffset--;
        while ($this->currentRow > $h + $this->scrollOffset - 3) $this->scrollOffset++;

        $path = $this->list->getPathForIndex($this->currentRow);
        $node = $this->list->getNodeForIndex($this->currentRow);
        
        $this->term->setCursor(1, $h-1);
        echo "\e[44;37m\e[K\e[1m{$this->shortfilename}\e[22m#\e[3m{$path}\e[37;23m";

        //$this->term->setCursor(1, $h);
        echo " = ";
        if ($node instanceof ValueNode) {
            echo json_encode($node->value, JSON_UNESCAPED_SLASHES|JSON_UNESCAPED_UNICODE);
        } elseif ($node instanceof ArrayNode) {
            echo "[…]";
        } elseif ($node instanceof ObjectNode) {
            echo "{…}";
        }
        echo "\e[0m";

        $this->redrawInfoBar();

        // $this->term->setCursor(1, $h);
        // echo "\e[0;37m\e[K";

        for ($n = 0; $n < $h - 2; $n++) {
            $this->list->drawEntry($n + 1, $n + $this->scrollOffset, $w, ($n + $this->scrollOffset == $this->currentRow));
        }
        // $this->term->setCursor(1, 1);
        // echo "\e[90;3m«Empty»\e[0m";
    }

    private function redrawInfoBar()
    {
        [$w,$h] = $this->term->getSize();

        $keys = [
            'e' => 'Edit',
            'E' => 'Edit key',
            'i' => 'Insert',
            'D' => 'Delete',
            'C' => 'Copy',
            'P' => 'Paste',
            '^C' => 'Exit',
        ];

        $this->term->setCursor(1, $h);
        echo "\e[0m\e[K";
        foreach ($keys as $key=>$info)
            echo " \e[1m{$key}\e[2m \e[3m{$info}\e[0m \e[90m\u{2502}\e[0m";
    }

}