'use strict';
/**
 * paste_create.js — Logic for the paste creation page.
 * Depends on: crypto.js (PasteCrypto), app.js (clearDraft, window.PBCFG)
 */

document.addEventListener('DOMContentLoaded', function () {
    const textarea   = document.getElementById('content');
    const submitBtn  = document.getElementById('submitBtn');
    const langSelect = document.getElementById('language');

    // ── Load languages from API ──────────────────────────────────────────────
    fetch('/api/languages')
        .then(r => r.json())
        .then(langs => {
            langSelect.innerHTML = '';
            langs.forEach(l => {
                const o = document.createElement('option');
                o.value = l.value;
                o.textContent = l.name;
                langSelect.appendChild(o);
            });
            // Restore last-used language preference
            const saved = localStorage.getItem('preferred_language');
            if (saved) langSelect.value = saved;
        })
        .catch(() => {});

    langSelect.addEventListener('change', () =>
        localStorage.setItem('preferred_language', langSelect.value));

    // ── Restore expiry preference ────────────────────────────────────────────
    const expirySelect = document.getElementById('expires_in');
    const savedExpiry  = localStorage.getItem('preferred_expiry');
    if (savedExpiry) expirySelect.value = savedExpiry;
    expirySelect.addEventListener('change', () =>
        localStorage.setItem('preferred_expiry', expirySelect.value));

    // ── Indent controls (Tabs / Spaces + size) ───────────────────────────────
    const indentType = document.getElementById('indent_type');
    const indentSize = document.getElementById('indent_size');

    // Restore saved preferences
    const savedIndentType = localStorage.getItem('preferred_indent_type');
    const savedIndentSize = localStorage.getItem('preferred_indent_size');
    if (savedIndentType) indentType.value = savedIndentType;
    if (savedIndentSize) indentSize.value = savedIndentSize;

    // Hide size selector when Tabs is chosen (tabs have no width setting in the input)
    function syncIndentUI() {
        indentSize.style.display = indentType.value === 'tabs' ? 'none' : '';
    }
    syncIndentUI();

    indentType.addEventListener('change', () => {
        localStorage.setItem('preferred_indent_type', indentType.value);
        syncIndentUI();
    });
    indentSize.addEventListener('change', () =>
        localStorage.setItem('preferred_indent_size', indentSize.value));

    // ── Tab key handler ──────────────────────────────────────────────────────
    textarea.addEventListener('keydown', function (e) {
        if (e.key !== 'Tab') return;
        e.preventDefault();

        const useTab  = indentType.value === 'tabs';
        const indent  = useTab ? '\t' : ' '.repeat(parseInt(indentSize.value, 10));

        const start = this.selectionStart;
        const end   = this.selectionEnd;
        const value = this.value;

        if (start === end) {
            // No selection — insert indent at cursor
            this.value = value.slice(0, start) + indent + value.slice(end);
            this.selectionStart = this.selectionEnd = start + indent.length;
        } else {
            // Multi-line selection — indent / unindent each line
            const lineStart = value.lastIndexOf('\n', start - 1) + 1;
            const selectedText = value.slice(lineStart, end);
            const lines = selectedText.split('\n');

            let newText;
            if (e.shiftKey) {
                // Unindent: remove one level of indent from the start of each line
                newText = lines.map(line => {
                    if (useTab) return line.startsWith('\t') ? line.slice(1) : line;
                    const spaces = parseInt(indentSize.value, 10);
                    return line.startsWith(' '.repeat(spaces))
                        ? line.slice(spaces)
                        : line.replace(/^ +/, m => m.slice(Math.min(m.length, spaces)));
                }).join('\n');
            } else {
                // Indent: prepend indent to each line
                newText = lines.map(line => indent + line).join('\n');
            }

            const removed = selectedText.length - newText.length; // negative when indenting
            this.value = value.slice(0, lineStart) + newText + value.slice(end);
            this.selectionStart = lineStart;
            this.selectionEnd   = lineStart + newText.length;
        }
    });

    // ── Enter key: auto-indent to match previous line ────────────────────────
    textarea.addEventListener('keydown', function (e) {
        if (e.key !== 'Enter') return;
        e.preventDefault();

        const start = this.selectionStart;
        const value = this.value;

        // Find the beginning of the current line
        const lineStart = value.lastIndexOf('\n', start - 1) + 1;
        const currentLine = value.slice(lineStart, start);

        // Grab the leading whitespace (spaces or tabs) of the current line
        const leadingWhitespace = currentLine.match(/^(\s*)/)[1];

        const insert = '\n' + leadingWhitespace;
        this.value = value.slice(0, start) + insert + value.slice(this.selectionEnd);
        this.selectionStart = this.selectionEnd = start + insert.length;
    });

    // ── Ctrl/Cmd+S shortcut ──────────────────────────────────────────────────
    document.addEventListener('keydown', e => {
        if ((e.ctrlKey || e.metaKey) && e.key === 's') {
            e.preventDefault();
            submitPaste();
        }
    });

    submitBtn.addEventListener('click', submitPaste);

    // ── Clear Draft ──────────────────────────────────────────────────────────
    const clearBtn = document.getElementById('clearBtn');
    if (clearBtn) {
        clearBtn.addEventListener('click', () => {
            console.log('[Clear] Manual clear requested.');
            
            // Clear the editor and title
            textarea.value = '';
            const title = document.getElementById('title');
            if (title) title.value = '';
            
            // Wipe the localStorage draft via the global helper in app.js
            if (typeof window.clearDraft === 'function') {
                window.clearDraft();
            } else {
                localStorage.removeItem('paste_draft');
            }
            
            textarea.focus();
            console.log('[Clear] Draft wiped.');
        });
    }

    // ── Submit ───────────────────────────────────────────────────────────────

    async function submitPaste() {
        const content    = textarea.value;
        const title      = document.getElementById('title').value || 'Untitled';
        const language   = langSelect.value;
        const expires_in = expirySelect.value;

        if (!content.trim()) { textarea.focus(); return; }

        // Read E2E flag from the already-loaded config (fetched by app.js at startup).
        // By the time the user clicks Save, window.PBCFG is guaranteed to be populated.
        const E2E = window.PBCFG?.features?.encrypt_pastes ?? true;

        submitBtn.disabled    = true;
        submitBtn.textContent = '…';

        try {
            let postBody, keyBase64 = null;
            if (E2E) {
                const keyLen = window.PBCFG?.pastes?.encryption_key_bits ?? 128;
                const key = await PasteCrypto.generateKey(keyLen);
                keyBase64 = await PasteCrypto.exportKey(key);
                const plain = JSON.stringify({ title, content, language });
                postBody = { encrypted_data: await PasteCrypto.encrypt(plain, key), expires_in };
            } else {
                postBody = { title, content, language, expires_in };
            }

            const resp   = await fetch('/create', {
                method:  'POST',
                headers: { 'Content-Type': 'application/json' },
                body:    JSON.stringify(postBody),
            });
            const result = await resp.json();

            if (result.error) {
                alert('Error: ' + result.error);
                submitBtn.disabled    = false;
                submitBtn.textContent = 'Save';
            } else {
                if (typeof window.clearDraft === 'function') {
                    window.clearDraft();
                }
                if (result.deletion_token) {
                    localStorage.setItem('del_' + result.paste_id, result.deletion_token);
                }
                window.location.href = result.url + (keyBase64 ? '#' + keyBase64 : '');
            }
        } catch (err) {
            console.error(err);
            alert('Failed to create paste. Try again.');
            submitBtn.disabled    = false;
            submitBtn.textContent = 'Save';
        }
    }
});