"""The User Manager: a table of sys::User components under a sys::UserService.

Like the other panels it takes the editor pane over from the canvas rather than
floating above it. `main` is what hides the canvas and puts this in its place;
this module knows only the frame it was handed.

Each sys::User component carries three properties:
    cred  — SHA-1 of "username:password" (20 bytes, base64 in the SAX)
    perm  — 32-bit int: four groups × 7 permission flags per group
    prov  — 8-bit byte: app/kits/svm provisioning flags
"""

import base64
import hashlib
import tkinter as tk
from tkinter import font as tkfont, messagebox, ttk
import xml.etree.ElementTree as ET

import app_state
import live_hooks
import sax_file
import undo
from sax_dom import set_prop_value

HEADER_BG = "#f2f2f2"

PERM_FLAGS = ["or", "ow", "oi", "ar", "aw", "ai", "ua"]
PERM_LABELS = "rwIRWIu"

PROV_FLAGS = [("app", 0x01), ("kits", 0x02), ("svm", 0x04)]


def _hash_credentials(username, password):
    """SHA-1 of 'username:password', the Sedona credential algorithm."""
    return base64.b64encode(
        hashlib.sha1(f"{username}:{password}".encode("utf-8")).digest()
    ).decode("ascii")


def _decode_perm(perm_val):
    """32-bit int -> list of four 7-element bool lists."""
    try:
        val = int(perm_val)
    except (TypeError, ValueError):
        val = 0
    groups = []
    for g in range(4):
        byte = (val >> (g * 8)) & 0xFF
        groups.append([(byte >> bit) & 1 == 1 for bit in range(7)])
    return groups


def _encode_perm(groups):
    """List of four 7-element bool lists -> 32-bit int."""
    val = 0
    for g, flags in enumerate(groups):
        byte = 0
        for bit, on in enumerate(flags):
            if on:
                byte |= (1 << bit)
        val |= (byte << (g * 8))
    return val


def _format_perm(perm_val):
    """Human-readable: '1=rwIRWIu, 2=rwIRWIu, ...'"""
    groups = _decode_perm(perm_val)
    parts = []
    for g, flags in enumerate(groups):
        chars = "".join(PERM_LABELS[i] if on else "-" for i, on in enumerate(flags))
        parts.append(f"{g + 1}={chars}")
    return ", ".join(parts)


def _decode_prov(prov_val):
    """8-bit byte -> dict of flag name -> bool."""
    try:
        val = int(prov_val)
    except (TypeError, ValueError):
        val = 0
    return {name: bool(val & mask) for name, mask in PROV_FLAGS}


def _encode_prov(flags_dict):
    val = 0
    for name, mask in PROV_FLAGS:
        if flags_dict.get(name):
            val |= mask
    return val


def _format_prov(prov_val):
    """Human-readable: 'app,kits,svm' for set flags."""
    flags = _decode_prov(prov_val)
    active = [name for name, on in flags.items() if on]
    return ",".join(active) if active else "(none)"


def _get_prop(comp, name):
    prop = comp.find(f"prop[@name='{name}']")
    return prop.get("val") if prop is not None else None


def _safe_int(val):
    if val is None:
        return 0
    try:
        return int(val)
    except (TypeError, ValueError):
        try:
            return int(float(val))
        except (TypeError, ValueError):
            return 0


def _get_users(service_comp):
    """Returns child comp elements, excluding uncached placeholders."""
    return [c for c in service_comp
            if c.tag == "comp" and c.get("name", "") != "..."]


def _resolve_comp(comp):
    """Re-locate a comp element in the current DOM by id (live mode rebuilds the tree)."""
    root = app_state.xml_root_element
    if root is None:
        return comp
    comp_id = comp.get("id")
    if comp_id is None:
        return comp
    for elem in root.iter("comp"):
        if elem.get("id") == comp_id:
            return elem
    return comp


def is_user_service(comp):
    """Whether a component is a sys::UserService (or looks like one in live mode)."""
    if comp is None:
        return False
    type_name = comp.get("type", "")
    if "UserService" in type_name:
        return True
    for child in comp:
        if child.tag == "comp" and "User" in child.get("type", ""):
            return True
    return False


class _PermissionsDialog:
    """Workbench-style permissions grid: Groups x Operator/Admin columns."""

    def __init__(self, parent, perm_val):
        self.result = None
        groups = _decode_perm(perm_val)

        self._dlg = tk.Toplevel(parent)
        self._dlg.title("Permissions")
        self._dlg.transient(parent)
        self._dlg.grab_set()
        self._dlg.resizable(False, False)

        grid = tk.Frame(self._dlg, padx=8, pady=8)
        grid.pack(fill=tk.BOTH, expand=True)

        COL_HEADERS = [
            ("Operator", ["Read", "Write", "Invoke"]),
            ("Admin", ["Read", "Write", "Invoke", "User"]),
        ]

        # header row 0: "Groups" + category spans
        tk.Label(grid, text="Groups", relief=tk.GROOVE, bg="#e8e8e8",
                 padx=4, pady=2).grid(row=0, column=0, rowspan=2, sticky=tk.NSEW)
        col = 1
        for cat_name, sub_cols in COL_HEADERS:
            span = len(sub_cols)
            tk.Label(grid, text=cat_name, relief=tk.GROOVE, bg="#d8e8f0",
                     font=("TkDefaultFont", 8, "bold"),
                     padx=4, pady=2).grid(row=0, column=col, columnspan=span,
                                          sticky=tk.NSEW)
            col += span

        # header row 1: sub-column names
        col = 1
        for _, sub_cols in COL_HEADERS:
            for sub in sub_cols:
                tk.Label(grid, text=sub, relief=tk.GROOVE, bg="#e8e8e8",
                         font=("TkDefaultFont", 7), padx=4, pady=1).grid(
                    row=1, column=col, sticky=tk.NSEW)
                col += 1

        # data rows
        self._perm_vars = []
        for g in range(4):
            r = g + 2
            tk.Label(grid, text=f"Group {g + 1}", relief=tk.GROOVE,
                     bg="#f4f4f4", padx=4, pady=1).grid(row=r, column=0,
                                                         sticky=tk.NSEW)
            gvars = []
            for f_idx in range(7):
                var = tk.BooleanVar(value=groups[g][f_idx])
                var.trace_add("write", lambda *_a, g=g, f=f_idx: self._on_perm_toggle(g, f))
                ttk.Checkbutton(grid, variable=var).grid(
                    row=r, column=f_idx + 1, padx=6, pady=1)
                gvars.append(var)
            self._perm_vars.append(gvars)

        # Clear All / Set All
        action_frame = tk.Frame(grid)
        action_frame.grid(row=6, column=0, columnspan=8, sticky=tk.E, pady=(6, 0))
        ttk.Button(action_frame, text="Clear All", width=8,
                   command=self._clear_all).pack(side=tk.LEFT, padx=2)
        ttk.Button(action_frame, text="Set All", width=8,
                   command=self._set_all).pack(side=tk.LEFT, padx=2)

        # OK / Cancel
        btn_frame = tk.Frame(self._dlg, pady=6)
        btn_frame.pack()
        ttk.Button(btn_frame, text="OK", width=10, command=self._on_ok).pack(
            side=tk.LEFT, padx=4)
        ttk.Button(btn_frame, text="Cancel", width=10, command=self._on_cancel).pack(
            side=tk.LEFT, padx=4)

        self._dlg.protocol("WM_DELETE_WINDOW", self._on_cancel)
        self._dlg.wait_window()

    def _on_perm_toggle(self, group, flag_idx):
        """Auto-cascade: write implies read, admin implies operator."""
        gvars = self._perm_vars[group]
        if not gvars[flag_idx].get():
            return
        # Flags: 0=or, 1=ow, 2=oi, 3=ar, 4=aw, 5=ai, 6=ua
        # Write (1) → Read (0); Admin Write (4) → Admin Read (3)
        if flag_idx in (1, 4):
            gvars[flag_idx - 1].set(True)
        # Admin flag (3,4,5) → same Operator flag (0,1,2)
        if 3 <= flag_idx <= 5:
            gvars[flag_idx - 3].set(True)

    def _clear_all(self):
        for gvars in self._perm_vars:
            for v in gvars:
                v.set(False)

    def _set_all(self):
        for gvars in self._perm_vars:
            for v in gvars:
                v.set(True)

    def _on_ok(self):
        groups = [[v.get() for v in gvars] for gvars in self._perm_vars]
        self.result = _encode_perm(groups)
        self._dlg.destroy()

    def _on_cancel(self):
        self._dlg.destroy()


class _ProvisioningDialog:
    """Provisioning flags popup: app, kits, svm checkboxes."""

    def __init__(self, parent, prov_val):
        self.result = None
        flags = _decode_prov(prov_val)

        self._dlg = tk.Toplevel(parent)
        self._dlg.title("Provisioning Permissions")
        self._dlg.transient(parent)
        self._dlg.grab_set()
        self._dlg.resizable(False, False)

        main = ttk.Frame(self._dlg, padding=10)
        main.pack(fill=tk.BOTH, expand=True)

        self._prov_vars = {}
        for name, _ in PROV_FLAGS:
            var = tk.BooleanVar(value=flags.get(name, False))
            ttk.Checkbutton(main, text=name, variable=var).pack(
                anchor=tk.W, pady=2)
            self._prov_vars[name] = var

        btn_frame = ttk.Frame(main)
        btn_frame.pack(pady=(10, 0))
        ttk.Button(btn_frame, text="OK", width=10, command=self._on_ok).pack(
            side=tk.LEFT, padx=4)
        ttk.Button(btn_frame, text="Cancel", width=10, command=self._on_cancel).pack(
            side=tk.LEFT, padx=4)

        self._dlg.protocol("WM_DELETE_WINDOW", self._on_cancel)
        self._dlg.wait_window()

    def _on_ok(self):
        self.result = _encode_prov(
            {name: var.get() for name, var in self._prov_vars.items()})
        self._dlg.destroy()

    def _on_cancel(self):
        self._dlg.destroy()


class _UserDialog:
    """Compact Edit/Add User dialog with >> buttons opening Permissions/Provisioning popups."""

    def __init__(self, parent, service_comp, user_elem, on_done):
        self._service_comp = service_comp
        self._user_elem = user_elem
        self._on_done = on_done
        self._is_edit = user_elem is not None

        self._perm_val = _safe_int(_get_prop(user_elem, "perm")) if self._is_edit else 0
        self._prov_val = _safe_int(_get_prop(user_elem, "prov")) if self._is_edit else 0

        self._dlg = tk.Toplevel(parent)
        self._dlg.title("Edit User" if self._is_edit else "Add User")
        self._dlg.transient(parent)
        self._dlg.grab_set()
        self._dlg.resizable(False, False)

        main = ttk.Frame(self._dlg, padding=10)
        main.pack(fill=tk.BOTH, expand=True)

        row = 0
        ttk.Label(main, text="Username").grid(row=row, column=0, sticky=tk.W, pady=2)
        self._name_var = tk.StringVar(
            value=user_elem.get("name", "") if self._is_edit else "")
        name_entry = ttk.Entry(main, textvariable=self._name_var, width=28)
        name_entry.grid(row=row, column=1, columnspan=2, sticky=tk.EW, pady=2)
        if self._is_edit:
            name_entry.config(state="disabled")

        row += 1
        ttk.Label(main, text="Password").grid(row=row, column=0, sticky=tk.W, pady=2)
        self._pass_var = tk.StringVar()
        ttk.Entry(main, textvariable=self._pass_var, show="*", width=28).grid(
            row=row, column=1, columnspan=2, sticky=tk.EW, pady=2)

        row += 1
        ttk.Label(main, text="Confirm").grid(row=row, column=0, sticky=tk.W, pady=2)
        self._confirm_var = tk.StringVar()
        ttk.Entry(main, textvariable=self._confirm_var, show="*", width=28).grid(
            row=row, column=1, columnspan=2, sticky=tk.EW, pady=2)

        # permissions summary + >> button
        row += 1
        ttk.Separator(main, orient=tk.HORIZONTAL).grid(
            row=row, column=0, columnspan=3, sticky=tk.EW, pady=6)

        row += 1
        ttk.Label(main, text="Permissions").grid(row=row, column=0, sticky=tk.W, pady=2)
        self._perm_label = tk.StringVar(value=_format_perm(self._perm_val))
        ttk.Label(main, textvariable=self._perm_label,
                  font=("TkDefaultFont", 8)).grid(
            row=row, column=1, sticky=tk.W, pady=2)
        ttk.Button(main, text="»", width=3,
                   command=self._open_permissions).grid(
            row=row, column=2, sticky=tk.E, pady=2)

        # provisioning summary + >> button
        row += 1
        ttk.Label(main, text="Provisioning Permissions").grid(
            row=row, column=0, sticky=tk.W, pady=2)
        self._prov_label = tk.StringVar(value=_format_prov(self._prov_val))
        ttk.Label(main, textvariable=self._prov_label,
                  font=("TkDefaultFont", 8)).grid(
            row=row, column=1, sticky=tk.W, pady=2)
        ttk.Button(main, text="»", width=3,
                   command=self._open_provisioning).grid(
            row=row, column=2, sticky=tk.E, pady=2)

        # OK / Cancel
        row += 1
        btn_frame = ttk.Frame(main)
        btn_frame.grid(row=row, column=0, columnspan=3, pady=(10, 0))
        ttk.Button(btn_frame, text="OK", width=10, command=self._on_ok).pack(
            side=tk.LEFT, padx=4)
        ttk.Button(btn_frame, text="Cancel", width=10, command=self._on_cancel).pack(
            side=tk.LEFT, padx=4)

        self._dlg.protocol("WM_DELETE_WINDOW", self._on_cancel)
        name_entry.focus_set()
        self._dlg.wait_window()

    def _open_permissions(self):
        dlg = _PermissionsDialog(self._dlg, self._perm_val)
        if dlg.result is not None:
            self._perm_val = dlg.result
            self._perm_label.set(_format_perm(self._perm_val))

    def _open_provisioning(self):
        dlg = _ProvisioningDialog(self._dlg, self._prov_val)
        if dlg.result is not None:
            self._prov_val = dlg.result
            self._prov_label.set(_format_prov(self._prov_val))

    def _on_ok(self):
        username = self._name_var.get().strip()
        password = self._pass_var.get()
        confirm = self._confirm_var.get()

        if not username:
            messagebox.showwarning("Validation", "Username is required.", parent=self._dlg)
            return
        if not self._is_edit and not password:
            messagebox.showwarning("Validation", "Password is required for new users.",
                                   parent=self._dlg)
            return
        if password and password != confirm:
            messagebox.showwarning("Validation", "Passwords do not match.", parent=self._dlg)
            return

        if not self._is_edit:
            for c in _get_users(self._service_comp):
                if c.get("name", "") == username:
                    messagebox.showwarning("Validation",
                                           f"User '{username}' already exists.",
                                           parent=self._dlg)
                    return

        if self._is_edit:
            self._apply_edit(username, password)
        else:
            self._apply_add(username, password)

        self._dlg.destroy()
        if self._on_done:
            self._on_done()

    def _apply_add(self, username, password):
        elem = ET.Element("comp", name=username, type="sys::User")
        cred = _hash_credentials(username, password)
        values = {"cred": cred, "perm": str(self._perm_val), "prov": str(self._prov_val)}

        if app_state.live_mode:
            # One Sox add carrying every config value, so the user never exists on the
            # device without its password and rights.
            try:
                config = sax_file.build_config_values("sys::User", values)
            except (ValueError, TypeError) as e:
                live_hooks.warn_failure("Add User", f"User '{username}' was not added to the device",
                                        f"A value does not fit its slot: {e}")
                return
            new_id = live_hooks.live_add_component(
                self._service_comp, "sys", "User", username, config)
            if new_id is None:
                live_hooks.warn_failure("Add User", f"User '{username}' was not added to the device")
                return
            elem.set("id", str(new_id))

        for name, val in values.items():
            ET.SubElement(elem, "prop", name=name, val=val)

        if app_state.live_mode:
            index = len(list(self._service_comp))
            self._service_comp.append(elem)
            undo.push(sax_file.LiveComponentCommand(
                self._service_comp, index, elem, present=True, label="add user"))
            app_state.mark_dirty()
            app_state.set_status(f"User '{username}' added to device.")
            return

        index = len(list(self._service_comp))
        cmd = undo.AddComponentCommand(self._service_comp, index, elem, label="add user")
        cmd.redo()
        undo.push(cmd)
        app_state.mark_dirty()

    def _apply_edit(self, username, password):
        user = self._user_elem
        changes = []

        new_perm = str(self._perm_val)
        old_perm = _get_prop(user, "perm")
        if new_perm != old_perm:
            changes.append((user, "perm", old_perm, new_perm))

        new_prov = str(self._prov_val)
        old_prov = _get_prop(user, "prov")
        if new_prov != old_prov:
            changes.append((user, "prov", old_prov, new_prov))

        if password:
            new_cred = _hash_credentials(username, password)
            old_cred = _get_prop(user, "cred")
            if new_cred != old_cred:
                changes.append((user, "cred", old_cred, new_cred))

        if not changes:
            return

        if app_state.live_mode:
            failures = []
            applied = []
            for change in changes:
                elem, prop, _old, new = change
                if live_hooks.live_set_prop_value(elem, prop, new):
                    set_prop_value(elem, prop, new)
                    applied.append(change)
                    app_state.mark_dirty()
                else:
                    failures.append(f"{prop}: {live_hooks.last_error}")
            if applied:
                undo.push(undo.LiveSlotValueCommand(applied, label="edit user"))
            if failures:
                live_hooks.warn_failure(
                    "Edit User",
                    f"{len(failures)} of {len(changes)} change(s) to user '{username}' did "
                    "not reach the device and were not applied",
                    "\n".join(f"  • {failure}" for failure in failures),
                )
            else:
                app_state.set_status(f"User '{username}' updated on device.")
            return

        cmd = undo.SlotValueCommand(changes, label="edit user")
        cmd.redo()
        undo.push(cmd)
        app_state.mark_dirty()

    def _on_cancel(self):
        self._dlg.destroy()


class UserServicePanel:
    """Table of users under a sys::UserService, with Add/Edit/Delete."""

    def __init__(self, parent, comp, on_change=None, on_close=None):
        self.comp = comp
        self.on_change = on_change
        self.on_close = on_close
        self.dirty = False
        self.frame = tk.Frame(parent)

        self._build_header()
        self._build_table()
        self._build_footer()
        self._refresh_table()

    def _build_header(self):
        header = tk.Frame(self.frame, padx=8, pady=6, bg=HEADER_BG)
        header.pack(fill=tk.X)

        name_font = tkfont.Font(family="Segoe UI", size=9, weight="bold")
        plain_font = tkfont.Font(family="Segoe UI", size=9)

        tk.Label(header, text="User Manager", font=name_font,
                 bg=HEADER_BG).pack(side=tk.LEFT)
        tk.Label(header, text=f"— {self.comp.get('name', '?')}",
                 font=plain_font, fg="#555555", bg=HEADER_BG).pack(side=tk.LEFT,
                                                                    padx=(8, 0))
        self.count_var = tk.StringVar(value="")
        tk.Label(header, textvariable=self.count_var, font=plain_font, fg="#555555",
                 bg=HEADER_BG).pack(side=tk.RIGHT)

    def _build_table(self):
        area = tk.Frame(self.frame)
        area.pack(fill=tk.BOTH, expand=True, padx=8, pady=(4, 0))

        columns = ("username", "permissions", "provisioning")
        self.table = ttk.Treeview(area, columns=columns, show="headings",
                                  selectmode="browse")
        self.table.heading("username", text="Username")
        self.table.heading("permissions", text="Group Permissions")
        self.table.heading("provisioning", text="Provisioning")

        self.table.column("username", width=120, minwidth=80)
        self.table.column("permissions", width=320, minwidth=200)
        self.table.column("provisioning", width=120, minwidth=80)

        vscroll = ttk.Scrollbar(area, orient=tk.VERTICAL, command=self.table.yview)
        self.table.configure(yscrollcommand=vscroll.set)

        self.table.pack(side=tk.LEFT, fill=tk.BOTH, expand=True)
        vscroll.pack(side=tk.RIGHT, fill=tk.Y)

        self.table.bind("<Double-1>", lambda _e: self._on_edit())
        self._user_elements = {}

    def _build_footer(self):
        footer = tk.Frame(self.frame, padx=8, pady=6)
        footer.pack(side=tk.BOTTOM, fill=tk.X)

        ttk.Button(footer, text="Close", width=9,
                   command=self.close).pack(side=tk.RIGHT)
        ttk.Button(footer, text="Delete User", width=12,
                   command=self._on_delete).pack(side=tk.RIGHT, padx=(0, 6))
        ttk.Button(footer, text="Edit User", width=12,
                   command=self._on_edit).pack(side=tk.RIGHT, padx=(0, 6))
        ttk.Button(footer, text="Add User", width=12,
                   command=self._on_add).pack(side=tk.RIGHT, padx=(0, 6))

    def _refresh_table(self):
        for item in self.table.get_children():
            self.table.delete(item)
        self._user_elements.clear()

        self.comp = _resolve_comp(self.comp)
        users = _get_users(self.comp)
        for user_elem in users:
            name = user_elem.get("name", "?")
            perm = _get_prop(user_elem, "perm")
            prov = _get_prop(user_elem, "prov")

            iid = self.table.insert("", tk.END, values=(
                name,
                _format_perm(perm),
                _format_prov(prov),
            ))
            self._user_elements[iid] = user_elem

        self.count_var.set(f"{len(users)} user{'' if len(users) == 1 else 's'}")

    def refresh(self):
        self._refresh_table()

    def _selected_user(self):
        sel = self.table.selection()
        if not sel:
            return None, None
        return sel[0], self._user_elements.get(sel[0])

    def _after_change(self):
        self._refresh_table()
        if self.on_change:
            self.on_change()

    def _on_add(self):
        _UserDialog(self.frame.winfo_toplevel(), self.comp, None, self._after_change)

    def _on_edit(self):
        iid, user_elem = self._selected_user()
        if user_elem is None:
            messagebox.showinfo("Edit User", "Select a user first.",
                                parent=self.frame.winfo_toplevel())
            return
        _UserDialog(self.frame.winfo_toplevel(), self.comp, user_elem, self._after_change)

    def _on_delete(self):
        iid, user_elem = self._selected_user()
        if user_elem is None:
            messagebox.showinfo("Delete User", "Select a user first.",
                                parent=self.frame.winfo_toplevel())
            return

        name = user_elem.get("name", "?")
        if not messagebox.askyesno("Delete User", f"Delete user '{name}'?",
                                   parent=self.frame.winfo_toplevel()):
            return

        if app_state.live_mode:
            # Read before it goes: once deleted, the device has nothing left to read back.
            snapshot = live_hooks.read_subtree(user_elem)
            unreadable = live_hooks.last_error if snapshot is None else ""
            if not live_hooks.live_delete_component(user_elem):
                live_hooks.warn_failure("Delete User", f"User '{name}' was not deleted from the device")
                return
            index = list(self.comp).index(user_elem)
            self.comp.remove(user_elem)
            app_state.mark_dirty()
            if snapshot is not None:
                undo.push(sax_file.LiveComponentCommand(
                    self.comp, index, user_elem, present=False, snapshot=snapshot,
                    label="delete user"))
                app_state.set_status(f"User '{name}' deleted from device.")
            else:
                app_state.set_status(
                    f"User '{name}' was deleted from the device, but this delete cannot be "
                    f"undone: {unreadable}", warn=True)
            self._after_change()
            return

        index = list(self.comp).index(user_elem)
        cmd = undo.AddComponentCommand(self.comp, index, user_elem, label="delete user")
        cmd.undo()
        undo.push(cmd)
        app_state.mark_dirty()
        self._after_change()

    def close(self):
        if self.on_close is not None:
            self.on_close()
        return True

    def destroy(self):
        if self.frame.winfo_exists():
            self.frame.destroy()


def build_user_service_panel(parent, comp, on_change=None, on_close=None):
    if comp is None or parent is None:
        return None
    return UserServicePanel(parent, comp, on_change=on_change, on_close=on_close)