/* $OpenBSD: window-switch.c,v 1.2 2026/07/14 17:17:18 nicm Exp $ */

/*

 * Copyright (c) 2026 Nicholas Marriott <nicholas.marriott@gmail.com>

 *

 * Permission to use, copy, modify, and distribute this software for any

 * purpose with or without fee is hereby granted, provided that the above

 * copyright notice and this permission notice appear in all copies.

 *

 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF

 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR

 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER

 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING

 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

 */

#include <sys/types.h>

#include <ctype.h>

#include <stdlib.h>

#include <string.h>

#include "tmux.h"

static struct screen  *window_switch_init(struct window_mode_entry *,

           struct cmdq_item *, struct cmd_find_state *,

           struct args *);

static void    window_switch_free(struct window_mode_entry *);

static void    window_switch_resize(struct window_mode_entry *, u_int,

           u_int);

static void    window_switch_key(struct window_mode_entry *,

           struct client *, struct session *,

           struct winlink *, key_code, struct mouse_event *);

static enum prompt_result window_switch_prompt_callback(void *, const char *,

           enum prompt_key_result);

#define WINDOW_SWITCH_DEFAULT_COMMAND "switch-client -Zt '%%'"

#define WINDOW_SWITCH_DEFAULT_FORMAT    \

  "#{?window_format," \

    "#{window_name} " \

    "#[dim]#{session_name}:#{window_index}#{window_flags}#[default] " \

    "#[dim]#{pane_current_command}#[default] " \

          "#[dim]#{?#{!=:#{pane_title},#{host_short}},#{pane_title},}#[default]" \

  "," \

    "#{session_name} " \

    "#[dim]#{session_windows} windows#[default] " \

    "#{?session_attached,attached,#[dim]detached#[default]} " \

    "#[dim]#{window_name}#[default]" \

  "}"

const struct window_mode window_switch_mode = {

  .name = "switch-mode",

  .default_format = WINDOW_SWITCH_DEFAULT_FORMAT,

  .init = window_switch_init,

  .free = window_switch_free,

  .resize = window_switch_resize,

  .key = window_switch_key,

};

enum window_switch_type {

  WINDOW_SWITCH_TYPE_SESSION,

  WINDOW_SWITCH_TYPE_WINDOW

};

struct window_switch_itemdata {

  enum window_switch_type  type;

  int      session;

  int      winlink;

  uint64_t     tag;

  char      *text;

  bitstr_t    *match;

  u_int      score;

  u_int      order;

};

struct window_switch_modedata {

  struct window_pane     *wp;

  struct screen       screen;

  int         zoomed;

  char         *format;

  char         *command;

  enum window_switch_type     type;

  char         *filter;

  struct prompt      *prompt;

  u_int         prompt_cx;

  struct window_switch_itemdata **item_list;

  u_int         item_size;

  struct window_switch_itemdata **matches;

  u_int         matches_size;

  u_int         current;

  u_int         offset;

};

static void

window_switch_free_item(struct window_switch_itemdata *item)

{

  free(item->match);

  free(item->text);

  free(item);

}

static struct window_switch_itemdata *

window_switch_add_item(struct window_switch_modedata *data)

{

  struct window_switch_itemdata *item;

  data->item_list = xreallocarray(data->item_list, data->item_size + 1,

      sizeof *data->item_list);

  item = data->item_list[data->item_size++] = xcalloc(1, sizeof *item);

  return (item);

}

static void

window_switch_add_session(struct window_switch_modedata *data,

    struct session *s, u_int *order)

{

  struct window_switch_itemdata *item;

  struct format_tree    *ft;

  ft = format_create(NULL, NULL, FORMAT_NONE, 0);

  format_defaults(ft, NULL, s, NULL, NULL);

  item = window_switch_add_item(data);

  item->type = WINDOW_SWITCH_TYPE_SESSION;

  item->session = s->id;

  item->winlink = -1;

  item->tag = (uint64_t)s;

  item->order = (*order)++;

  item->text = format_expand(ft, data->format);

  format_free(ft);

}

static void

window_switch_add_window(struct window_switch_modedata *data,

    struct winlink *wl, u_int *order)

{

  struct window_switch_itemdata *item;

  struct format_tree    *ft;

  ft = format_create(NULL, NULL, FORMAT_NONE, 0);

  format_defaults(ft, NULL, wl->session, wl, NULL);

  item = window_switch_add_item(data);

  item->type = WINDOW_SWITCH_TYPE_WINDOW;

  item->session = wl->session->id;

  item->winlink = wl->idx;

  item->tag = (uint64_t)wl;

  item->order = (*order)++;

  item->text = format_expand(ft, data->format);

  format_free(ft);

}

static int

window_switch_compare(const void *a0, const void *b0)

{

  struct window_switch_itemdata *const *a = a0;

  struct window_switch_itemdata *const *b = b0;

  if ((*a)->score > (*b)->score)

    return (-1);

  if ((*a)->score < (*b)->score)

    return (1);

  if ((*a)->order < (*b)->order)

    return (-1);

  if ((*a)->order > (*b)->order)

    return (1);

  return (0);

}

static void

window_switch_build(struct window_switch_modedata *data)

{

  struct window_switch_itemdata  *item, **m = NULL;

  const char       *f = data->filter;

  u_int         ns, nw, i, n = 0, order = 0;

  u_int         sx = screen_size_x(&data->screen);

  struct session      **sl;

  struct winlink      **wl;

  struct sort_criteria      sort_crit;

  sort_crit.order = SORT_NAME;

  sort_crit.reversed = 0;

  for (i = 0; i < data->item_size; i++)

    window_switch_free_item(data->item_list[i]);

  free(data->item_list);

  data->item_list = NULL;

  data->item_size = 0;

  switch (data->type) {

  case WINDOW_SWITCH_TYPE_SESSION:

    sl = sort_get_sessions(&ns, &sort_crit);

    for (i = 0; i < ns; i++)

      window_switch_add_session(data, sl[i], &order);

    break;

  case WINDOW_SWITCH_TYPE_WINDOW:

    wl = sort_get_winlinks(&nw, &sort_crit);

    for (i = 0; i < nw; i++)

      window_switch_add_window(data, wl[i], &order);

    break;

  }

  for (i = 0; i < data->item_size; i++) {

    item = data->item_list[i];

    if (*f == '\0') {

      m = xreallocarray(m, n + 1, sizeof *m);

      m[n++] = item;

      continue;

    }

    item->match = fuzzy_match(f, item->text, sx, &item->score);

    if (item->match == NULL)

      continue;

    m = xreallocarray(m, n + 1, sizeof *m);

    m[n++] = item;

  }

  qsort(m, n, sizeof *m, window_switch_compare);

  free(data->matches);

  data->matches = m;

  data->matches_size = n;

}

static u_int

window_switch_visible(struct window_switch_modedata *data)

{

  u_int sy = screen_size_y(&data->screen);

  if (sy <= 1)

    return (0);

  return (sy - 1);

}

static void

window_switch_set_current(struct window_switch_modedata *data, u_int current)

{

  u_int visible = window_switch_visible(data);

  if (data->matches_size == 0) {

    data->current = 0;

    data->offset = 0;

    return;

  }

  if (current > data->matches_size - 1)

    current = data->matches_size - 1;

  data->current = current;

  if (data->current < data->offset)

    data->offset = data->current;

  else if (visible != 0 && data->current >= data->offset + visible)

    data->offset = data->current - visible + 1;

}

static void

window_switch_draw_screen(struct window_mode_entry *wme)

{

  struct window_pane    *wp = wme->wp;

  struct window_switch_modedata *data = wme->data;

  struct options      *oo = wp->options;

  struct screen_write_ctx    ctx;

  struct screen     *s = &data->screen;

  u_int        sx = screen_size_x(s), i, j;

  u_int        sy = screen_size_y(s), visible, idx;

  struct window_switch_itemdata *item;

  struct grid_cell     mgc, sgc, gc;

  const struct grid_cell    *dgc = &grid_default_cell;

  struct prompt_draw_data    pdd;

  screen_write_start(&ctx, s);

  screen_write_clearscreen(&ctx, 8);

  if (sy <= 1) {

    screen_write_stop(&ctx);

    return;

  }

  style_apply(&mgc, oo, "switch-mode-match-style", NULL);

  style_apply(&sgc, oo, "mode-style", NULL);

  visible = window_switch_visible(data);

  for (i = 0; i < visible; i++) {

    idx = data->offset + i;

    if (idx >= data->matches_size)

      break;

    item = data->matches[idx];

    screen_write_cursormove(&ctx, 0, i, 0);

    if (idx != data->current)

      format_draw(&ctx, dgc, sx, item->text, NULL, 0);

    else {

      screen_write_clearendofline(&ctx, sgc.bg);

      format_draw(&ctx, &sgc, sx, item->text, NULL, 0);

    }

    if (item->match == NULL)

      continue;

    for (j = 0; j < sx; j++) {

      if (!bit_test(item->match, j))

        continue;

      grid_get_cell(s->grid, j, i, &gc);

      gc.attr = mgc.attr;

      gc.fg = mgc.fg;

      gc.bg = mgc.bg;

      screen_write_cursormove(&ctx, j, i, 0);

      screen_write_cell(&ctx, &gc);

    }

  }

  if (data->prompt != NULL) {

    pdd.ctx = &ctx;

    pdd.cursor_x = &data->prompt_cx;

    pdd.area_x = 0;

    pdd.area_width = sx;

    pdd.prompt_line = sy - 1;

    s->mode |= MODE_CURSOR;

    prompt_draw(data->prompt, &pdd);

    screen_write_cursormove(&ctx, data->prompt_cx, sy - 1, 0);

  }

  screen_write_stop(&ctx);

}

static struct screen *

window_switch_init(struct window_mode_entry *wme,

    __unused struct cmdq_item *item, struct cmd_find_state *fs,

    struct args *args)

{

  struct window_pane    *wp = wme->wp;

  struct window_switch_modedata *data;

  struct screen     *s;

  struct prompt_create_data  pd;

  wme->data = data = xcalloc(1, sizeof *data);

  data->wp = wp;

  if (args_has(args, 'w'))

    data->type = WINDOW_SWITCH_TYPE_WINDOW;

  else

    data->type = WINDOW_SWITCH_TYPE_SESSION;

  data->filter = xstrdup("");

  if (args == NULL || !args_has(args, 'F'))

    data->format = xstrdup(WINDOW_SWITCH_DEFAULT_FORMAT);

  else

    data->format = xstrdup(args_get(args, 'F'));

  if (args == NULL || args_count(args) == 0)

    data->command = xstrdup(WINDOW_SWITCH_DEFAULT_COMMAND);

  else

    data->command = xstrdup(args_string(args, 0));

  memset(&pd, 0, sizeof pd);

  prompt_set_options(&pd, fs->s);

  pd.fs = fs;

  pd.prompt = "(search) ";

  pd.input = "";

  pd.type = PROMPT_TYPE_SEARCH;

  pd.flags = PROMPT_INCREMENTAL|PROMPT_NOFORMAT|PROMPT_ISMODE|

      PROMPT_EDITARROWS;

  pd.inputcb = window_switch_prompt_callback;

  pd.data = data;

  data->prompt = prompt_create(&pd);

  prompt_update(data->prompt, "(search) ", data->filter);

  if (!args_has(args, 'Z'))

    data->zoomed = -1;

  else {

    data->zoomed = (wp->window->flags & WINDOW_ZOOMED);

    if (!data->zoomed && window_zoom(wp) == 0)

      server_redraw_window(wp->window);

  }

  s = &data->screen;

  screen_init(s, screen_size_x(&wp->base), screen_size_y(&wp->base), 0);

  window_switch_build(data);

  prompt_incremental_start(data->prompt);

  window_switch_draw_screen(wme);

  return (s);

}

static void

window_switch_free(struct window_mode_entry *wme)

{

  struct window_switch_modedata *data = wme->data;

  u_int        i;

  if (data->zoomed == 0)

    server_unzoom_window(wme->wp->window);

  for (i = 0; i < data->item_size; i++)

    window_switch_free_item(data->item_list[i]);

  free(data->item_list);

  free(data->matches);

  free(data->filter);

  prompt_free(data->prompt);

  free(data->format);

  free(data->command);

  screen_free(&data->screen);

  free(data);

}

static void

window_switch_resize(struct window_mode_entry *wme, u_int sx, u_int sy)

{

  struct window_switch_modedata *data = wme->data;

  struct screen     *s = &data->screen;

  screen_resize(s, sx, sy, 0);

  window_switch_build(data);

  window_switch_set_current(data, data->current);

  window_switch_draw_screen(wme);

}

static int

window_switch_run_command(struct window_switch_modedata *data, struct client *c)

{

  struct window_switch_itemdata *item;

  struct cmd_find_state    fs;

  struct session      *s;

  struct winlink      *wl;

  char        *target = NULL;

  struct cmdq_state   *state;

  char        *command, *error;

  enum cmd_parse_status    status;

  if (data->matches_size == 0)

    return (0);

  item = data->matches[data->current];

  cmd_find_clear_state(&fs, 0);

  switch (item->type) {

  case WINDOW_SWITCH_TYPE_SESSION:

    s = session_find_by_id(item->session);

    if (s != NULL) {

      xasprintf(&target, "=%s:", s->name);

      cmd_find_from_session(&fs, s, 0);

    }

    break;

  case WINDOW_SWITCH_TYPE_WINDOW:

    s = session_find_by_id(item->session);

    if (s != NULL) {

      wl = winlink_find_by_index(&s->windows, item->winlink);

      if (s != NULL && wl != NULL) {

        xasprintf(&target, "=%s:%u.", s->name, wl->idx);

        cmd_find_from_winlink(&fs, wl, 0);

      }

    }

    break;

  }

  if (target == NULL)

    return (0);

  command = cmd_template_replace(data->command, target, 1);

  if (command != NULL && *command != '\0') {

    state = cmdq_new_state(&fs, NULL, 0);

    status = cmd_parse_and_append(command, NULL, c, state, &error);

    if (status == CMD_PARSE_ERROR) {

      if (c != NULL) {

        *error = toupper((u_char)*error);

        status_message_set(c, -1, 1, 0, 0, "%s", error);

      }

      free(error);

    }

    cmdq_free_state(state);

  }

  free(command);

  free(target);

  return (1);

}

static enum prompt_result

window_switch_prompt_callback(void *arg, const char *s,

    enum prompt_key_result key)

{

  struct window_switch_modedata *data = arg;

  if (key != PROMPT_KEY_HANDLED)

    return (PROMPT_CONTINUE);

  if (s == NULL)

    s = "";

  else if (*s != '\0')

    s++;

  free(data->filter);

  data->filter = xstrdup(s);

  window_switch_build(data);

  data->current = 0;

  data->offset = 0;

  return (PROMPT_CONTINUE);

}

static void

window_switch_key(struct window_mode_entry *wme, struct client *c,

    __unused struct session *s, __unused struct winlink *wl, key_code key,

    struct mouse_event *m)

{

  struct window_pane    *wp = wme->wp;

  struct window_switch_modedata *data = wme->data;

  u_int        visible, current = data->current;

  u_int        x, y, size = data->matches_size;

  enum prompt_key_result     result;

  int        redraw = 0;

  if (KEYC_IS_MOUSE(key)) {

    if (m == NULL || cmd_mouse_at(wp, m, &x, &y, 0) != 0)

      return;

    if (data->prompt != NULL && screen_size_y(&data->screen) != 0 &&

        y == screen_size_y(&data->screen) - 1 &&

        MOUSE_BUTTONS(m->b) == MOUSE_BUTTON_1 && !MOUSE_DRAG(m->b) &&

        !MOUSE_RELEASE(m->b)) {

      result = prompt_mouse(data->prompt, x, 0,

          screen_size_x(&data->screen), &redraw);

      if (redraw || result == PROMPT_KEY_HANDLED) {

        window_switch_draw_screen(wme);

        wp->flags |= PANE_REDRAW;

      }

      return;

    }

    switch (key) {

    case KEYC_WHEELUP_PANE:

      if (size != 0 && current != 0)

        window_switch_set_current(data, current - 1);

      goto moved;

    case KEYC_WHEELDOWN_PANE:

      if (size != 0 && current != size - 1)

        window_switch_set_current(data, current + 1);

      goto moved;

    case KEYC_MOUSEDOWN1_PANE:

    case KEYC_DOUBLECLICK1_PANE:

      if (y >= window_switch_visible(data) ||

          data->offset + y >= size)

        return;

      window_switch_set_current(data, data->offset + y);

      if (key == KEYC_DOUBLECLICK1_PANE) {

        if (window_switch_run_command(data, c))

          window_pane_reset_mode(wp);

        return;

      }

      goto moved;

    }

    return;

  }

  switch (key) {

  case 'p'|KEYC_CTRL:

  case 'k'|KEYC_CTRL:

    key = KEYC_UP;

    break;

  case 'n'|KEYC_CTRL:

  case 'j'|KEYC_CTRL:

    key = KEYC_DOWN;

    break;

  }

  switch (key) {

  case '\r':

    if (window_switch_run_command(data, c))

      window_pane_reset_mode(wp);

    return;

  case '\033': /* Escape */

  case '['|KEYC_CTRL:

  case 'c'|KEYC_CTRL:

  case 'g'|KEYC_CTRL:

    window_pane_reset_mode(wp);

    return;

  }

  if (data->prompt != NULL) {

    result = prompt_key(data->prompt, key, &redraw);

    if (redraw) {

      window_switch_draw_screen(wme);

      wp->flags |= PANE_REDRAW;

    }

    if (result == PROMPT_KEY_HANDLED ||

        result == PROMPT_KEY_NOT_HANDLED)

      return;

    current = data->current;

    size = data->matches_size;

  }

  switch (key) {

  case KEYC_UP:

    if (size == 0)

      goto moved;

    if (current == 0)

      window_switch_set_current(data, size - 1);

    else

      window_switch_set_current(data, current - 1);

    goto moved;

  case KEYC_DOWN:

    if (size == 0)

      goto moved;

    if (current == size - 1)

      window_switch_set_current(data, 0);

    else

      window_switch_set_current(data, current + 1);

    goto moved;

  case KEYC_PPAGE:

    visible = window_switch_visible(data);

    if (current >= visible)

      window_switch_set_current(data, current - visible);

    else

      window_switch_set_current(data, 0);

    goto moved;

  case KEYC_NPAGE:

    visible = window_switch_visible(data);

    window_switch_set_current(data, current + visible);

    goto moved;

  case KEYC_HOME:

    window_switch_set_current(data, 0);

    goto moved;

  case KEYC_END:

    if (size > 0)

      window_switch_set_current(data, size - 1);

    goto moved;

  }

moved:

  window_switch_draw_screen(wme);

  wp->flags |= PANE_REDRAW;

}