Refactor schema to support versioning of pages. Add HistoryDialog and diff with ability to revert.

bouquin/history_dialog.py

@@ -0,0 +1,179 @@
+from __future__ import annotations
+
+import difflib, re, html as _html
+from PySide6.QtCore import Qt, Slot
+from PySide6.QtWidgets import (
+    QDialog,
+    QVBoxLayout,
+    QHBoxLayout,
+    QListWidget,
+    QListWidgetItem,
+    QPushButton,
+    QMessageBox,
+    QTextBrowser,
+    QTabWidget,
+)
+
+
+def _html_to_text(s: str) -> str:
+    """Lightweight HTML→text for diff (keeps paragraphs/line breaks)."""
+    STYLE_SCRIPT_RE = re.compile(r"(?is)<(script|style)[^>]*>.*?</\1>")
+    COMMENT_RE = re.compile(r"<!--.*?-->", re.S)
+    BR_RE = re.compile(r"(?i)<br\s*/?>")
+    BLOCK_END_RE = re.compile(r"(?i)</(p|div|section|article|li|h[1-6])\s*>")
+    TAG_RE = re.compile(r"<[^>]+>")
+    MULTINL_RE = re.compile(r"\n{3,}")
+
+    s = STYLE_SCRIPT_RE.sub("", s)
+    s = COMMENT_RE.sub("", s)
+    s = BR_RE.sub("\n", s)
+    s = BLOCK_END_RE.sub("\n", s)
+    s = TAG_RE.sub("", s)
+    s = _html.unescape(s)
+    s = MULTINL_RE.sub("\n\n", s)
+    return s.strip()
+
+
+def _colored_unified_diff_html(old_html: str, new_html: str) -> str:
+    """Return HTML with colored unified diff (+ green, - red, context gray)."""
+    a = _html_to_text(old_html).splitlines()
+    b = _html_to_text(new_html).splitlines()
+    ud = difflib.unified_diff(a, b, fromfile="current", tofile="selected", lineterm="")
+    lines = []
+    for line in ud:
+        if line.startswith("+") and not line.startswith("+++"):
+            lines.append(
+                f"<span style='color:#116329'>+ {_html.escape(line[1:])}</span>"
+            )
+        elif line.startswith("-") and not line.startswith("---"):
+            lines.append(
+                f"<span style='color:#b31d28'>- {_html.escape(line[1:])}</span>"
+            )
+        elif line.startswith("@@"):
+            lines.append(f"<span style='color:#6f42c1'>{_html.escape(line)}</span>")
+        else:
+            lines.append(f"<span style='color:#586069'>{_html.escape(line)}</span>")
+    css = "pre { font-family: Consolas,Menlo,Monaco,monospace; font-size: 13px; }"
+    return f"<style>{css}</style><pre>{'<br>'.join(lines)}</pre>"
+
+
+class HistoryDialog(QDialog):
+    """Show versions for a date, preview, diff, and allow revert."""
+
+    def __init__(self, db, date_iso: str, parent=None):
+        super().__init__(parent)
+        self.setWindowTitle(f"History — {date_iso}")
+        self._db = db
+        self._date = date_iso
+        self._versions = []  # list[dict] from DB
+        self._current_id = None  # id of current
+
+        root = QVBoxLayout(self)
+
+        # Top: list of versions
+        top = QHBoxLayout()
+        self.list = QListWidget()
+        self.list.setMinimumSize(500, 650)
+        self.list.currentItemChanged.connect(self._on_select)
+        top.addWidget(self.list, 1)
+
+        # Right: tabs (Preview / Diff vs current)
+        self.tabs = QTabWidget()
+        self.preview = QTextBrowser()
+        self.preview.setOpenExternalLinks(True)
+        self.diff = QTextBrowser()
+        self.diff.setOpenExternalLinks(False)
+        self.tabs.addTab(self.preview, "Preview")
+        self.tabs.addTab(self.diff, "Diff vs current")
+        self.tabs.setMinimumSize(500, 650)
+        top.addWidget(self.tabs, 2)
+
+        root.addLayout(top)
+
+        # Buttons
+        row = QHBoxLayout()
+        row.addStretch(1)
+        self.btn_revert = QPushButton("Revert to Selected")
+        self.btn_revert.clicked.connect(self._revert)
+        self.btn_close = QPushButton("Close")
+        self.btn_close.clicked.connect(self.reject)
+        row.addWidget(self.btn_revert)
+        row.addWidget(self.btn_close)
+        root.addLayout(row)
+
+        self._load_versions()
+
+    # --- Data/UX helpers ---
+    def _load_versions(self):
+        self._versions = self._db.list_versions(
+            self._date
+        )  # [{id,version_no,created_at,note,is_current}]
+        self._current_id = next(
+            (v["id"] for v in self._versions if v["is_current"]), None
+        )
+        self.list.clear()
+        for v in self._versions:
+            label = f"v{v['version_no']} — {v['created_at']}"
+            if v.get("note"):
+                label += f"  ·  {v['note']}"
+            if v["is_current"]:
+                label += "  **(current)**"
+            it = QListWidgetItem(label)
+            it.setData(Qt.UserRole, v["id"])
+            self.list.addItem(it)
+        # select the first non-current if available, else current
+        idx = 0
+        for i, v in enumerate(self._versions):
+            if not v["is_current"]:
+                idx = i
+                break
+        if self.list.count():
+            self.list.setCurrentRow(idx)
+
+    @Slot()
+    def _on_select(self):
+        item = self.list.currentItem()
+        if not item:
+            self.preview.clear()
+            self.diff.clear()
+            self.btn_revert.setEnabled(False)
+            return
+        sel_id = item.data(Qt.UserRole)
+        # Preview selected as HTML
+        sel = self._db.get_version(version_id=sel_id)
+        self.preview.setHtml(sel["content"])
+        # Diff vs current (textual diff)
+        cur = self._db.get_version(version_id=self._current_id)
+        self.diff.setHtml(_colored_unified_diff_html(cur["content"], sel["content"]))
+        # Enable revert only if selecting a non-current
+        self.btn_revert.setEnabled(sel_id != self._current_id)
+
+    @Slot()
+    def _revert(self):
+        item = self.list.currentItem()
+        if not item:
+            return
+        sel_id = item.data(Qt.UserRole)
+        if sel_id == self._current_id:
+            return
+        sel = self._db.get_version(version_id=sel_id)
+        vno = sel["version_no"]
+        # Confirm
+        if (
+            QMessageBox.question(
+                self,
+                "Revert",
+                f"Revert {self._date} to version v{vno}?\n\nYou can always change your mind later.",
+                QMessageBox.Yes | QMessageBox.No,
+            )
+            != QMessageBox.Yes
+        ):
+            return
+        # Flip head pointer
+        try:
+            self._db.revert_to_version(self._date, version_id=sel_id)
+        except Exception as e:
+            QMessageBox.critical(self, "Revert failed", str(e))
+            return
+        QMessageBox.information(self, "Reverted", f"{self._date} is now at v{vno}.")
+        self.accept()  # let the caller refresh the editor