"""
views/config_tui.py — curses-based configuration wizard.

Run:  python -m views.config_tui
Or:   python views/config_tui.py
"""

import curses
import sys
import os

# Ensure project root is on path when run directly
sys.path.insert(0, os.path.join(os.path.dirname(__file__), ".."))

from config.schema import AppConfig, DatabaseConfig, SecurityConfig, ServerConfig, TenorConfig
from config.config import load, save

# ── field descriptors ──────────────────────────────────────
SECTION_FIELDS = [
    ("server", "Server", [
        ("host",      "Host",           str,   "0.0.0.0"),
        ("port",      "Port",           int,   8080),
        ("debug",     "Debug mode",     bool,  False),
    ]),
    ("security", "Security", [
        ("secret",          "Encryption secret",   str, "default_secret_change_me"),
        ("salt",            "Encryption salt",     str, "default_salt_change_me"),
        ("admin_token",     "Admin token",         str, ""),
        ("rate_limit",      "Rate limit (msg)",    int, 5),
        ("rate_window",     "Rate window (sec)",   int, 10),
        ("max_message_length", "Max msg length",   int, 2000),
    ]),
    ("db", "Database", [
        ("engine",           "Engine (sqlite|mariadb)", str, "sqlite"),
        ("sqlite_path",      "SQLite path",             str, "chat.db"),
        ("mariadb_host",     "MariaDB host",            str, "localhost"),
        ("mariadb_port",     "MariaDB port",            int, 3306),
        ("mariadb_user",     "MariaDB user",            str, "chat"),
        ("mariadb_password", "MariaDB password",        str, "chat"),
        ("mariadb_database", "MariaDB database",        str, "chat"),
    ]),
    ("tenor", "Tenor API", [
        ("api_key", "API key", str, ""),
    ]),
]

# ── helpers ────────────────────────────────────────────────
def draw_menu(std, items, selected, top, height, width, title):
    """Draw a scrollable list and return the new top index."""
    std.attron(curses.A_REVERSE)
    std.addstr(0, 0, f" {title} ".center(width, "─"))
    std.attroff(curses.A_REVERSE)

    n = len(items)
    visible = height - 2  # header + status line
    # clamp top
    if selected < top:
        top = selected
    if selected >= top + visible:
        top = selected - visible + 1
    top = max(0, min(top, n - visible))

    for i in range(visible):
        idx = top + i
        if idx >= n:
            break
        line = f" {items[idx]}"
        if idx == selected:
            std.attron(curses.A_REVERSE)
            std.addstr(1 + i, 0, line.ljust(width))
            std.attroff(curses.A_REVERSE)
        else:
            std.addstr(1 + i, 0, line.ljust(width))

    # status bar
    std.attron(curses.A_REVERSE)
    std.addstr(height - 1, 0, f" {selected+1}/{n}  ↑↓ scroll  ← back  ".ljust(width))
    std.attroff(curses.A_REVERSE)

    return top


def edit_field(std, label, value, field_type):
    """Inline edit a field value. Returns new value or None if cancelled."""
    h, w = std.getmaxyx()
    prompt = f" {label}: "
    # clear a couple lines
    for y in range(2):
        std.addstr(h // 2 + y, 0, " " * w)

    std.addstr(h // 2, 0, prompt)
    # pre-fill with current value
    start = len(prompt)
    curses.echo()
    curses.curs_set(1)
    raw = std.getstr(h // 2, start, w - start - 2).decode("utf-8", errors="replace").strip()
    curses.noecho()
    curses.curs_set(0)
    if not raw:
        # keep old value
        return value
    if field_type == bool:
        return raw.lower() in ("1", "true", "yes", "y")
    if field_type == int:
        try:
            return int(raw)
        except ValueError:
            return value
    return raw


def run_config_tui(std, cfg: AppConfig) -> AppConfig | None:
    curses.curs_set(0)
    curses.use_default_colors()
    h, w = std.getmaxyx()
    if h < 12 or w < 50:
        std.addstr(0, 0, "Terminal too small (min 50x12)")
        std.refresh()
        std.getch()
        return None

    # section list on the left
    section_names = [s[1] for s in SECTION_FIELDS]  # display names
    section_data = [(s[0], s[2]) for s in SECTION_FIELDS]  # (attr_name, fields)

    sel_section = 0
    sel_field = 0
    top_section = 0

    while True:
        std.erase()
        h, w = std.getmaxyx()
        left_w = min(20, w // 3)

        # draw sections
        sname = section_names[sel_section]
        draw_menu(std, section_names, sel_section, top_section, h, left_w, "Sections")

        # draw field list on the right
        sec_attr, fields = section_data[sel_section]
        current_obj = getattr(cfg, sec_attr)
        field_labels = [f"{f[1]}: {getattr(current_obj, f[0])}" for f in fields]
        draw_menu(std, field_labels, sel_field, 0, h, w - left_w - 1, sname)

        key = std.getch()

        if key == curses.KEY_UP:
            sel_field = max(0, sel_field - 1)
        elif key == curses.KEY_DOWN:
            sel_field = min(len(fields) - 1, sel_field + 1)
        elif key == curses.KEY_LEFT:
            sel_section = max(0, sel_section - 1)
            sel_field = 0
            top_section = 0
        elif key == curses.KEY_RIGHT:
            sel_section = min(len(section_names) - 1, sel_section + 1)
            sel_field = 0
            top_section = 0
        elif key == ord("\n") or key == ord(" "):
            # edit selected field
            field_name, field_label, field_type, _ = fields[sel_field]
            old = getattr(current_obj, field_name)
            new = edit_field(std, field_label, old, field_type)
            if new is not None:
                setattr(current_obj, field_name, new)
        elif key == ord("\t") or key == ord("s") or key == ord("S"):
            # Save
            save(cfg)
            return cfg
        elif key == ord("q") or key == 27:  # ESC
            return None


def main_std(std):
    cfg = load()
    result = run_config_tui(std, cfg)
    if result:
        save(result)
        msg = " ✓ Config saved!"
    else:
        msg = " ✗ Cancelled."
    h, w = std.getmaxyx()
    std.addstr(h - 1, 0, msg.ljust(w - 1))
    std.refresh()
    std.getch()


def main():
    curses.wrapper(main_std)


if __name__ == "__main__":
    main()