/*
 * data-types.c
 * Copyright (C) 2016 Kovid Goyal <kovid at kovidgoyal.net>
 *
 * Distributed under terms of the GPL3 license.
 */

#ifdef __APPLE__
// Needed for _CS_DARWIN_USER_CACHE_DIR
#define _DARWIN_C_SOURCE
#include <unistd.h>
#undef _DARWIN_C_SOURCE
#endif

#include "data-types.h"
#include "base64.h"
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>
#include "cleanup.h"
#include "safe-wrappers.h"
#include "control-codes.h"
#include "wcwidth-std.h"
#include "wcswidth.h"
#include "modes.h"
#include <stddef.h>
#include <termios.h>
#include <signal.h>
#include <fcntl.h>
#include <stdio.h>
#include <locale.h>

#ifdef WITH_PROFILER
#include <gperftools/profiler.h>
#endif

#include "monotonic.h"

#ifdef __APPLE__
#include <libproc.h>
#include <xlocale.h>

static PyObject*
user_cache_dir(void) {
    static char buf[1024];
    if (!confstr(_CS_DARWIN_USER_CACHE_DIR, buf, sizeof(buf) - 1)) return PyErr_SetFromErrno(PyExc_OSError);
    return PyUnicode_FromString(buf);
}

static PyObject*
process_group_map(void) {
    int num_of_processes = proc_listallpids(NULL, 0);
    size_t bufsize = sizeof(pid_t) * (num_of_processes + 1024);
    RAII_ALLOC(pid_t, buf, malloc(bufsize));
    if (!buf) return PyErr_NoMemory();
    num_of_processes = proc_listallpids(buf, (int)bufsize);
    PyObject *ans = PyTuple_New(num_of_processes);
    if (ans == NULL) { return PyErr_NoMemory(); }
    for (int i = 0; i < num_of_processes; i++) {
        long pid = buf[i], pgid = getpgid(buf[i]);
        PyObject *t = Py_BuildValue("ll", pid, pgid);
        if (t == NULL) { Py_DECREF(ans); return NULL; }
        PyTuple_SET_ITEM(ans, i, t);
    }
    return ans;
}
#endif

static PyObject*
redirect_std_streams(PyObject UNUSED *self, PyObject *args) {
    char *devnull = NULL;
    if (!PyArg_ParseTuple(args, "s", &devnull)) return NULL;
    if (freopen(devnull, "r", stdin) == NULL) return PyErr_SetFromErrno(PyExc_OSError);
    if (freopen(devnull, "w", stdout) == NULL) return PyErr_SetFromErrno(PyExc_OSError);
    if (freopen(devnull, "w", stderr) == NULL)  return PyErr_SetFromErrno(PyExc_OSError);
    Py_RETURN_NONE;
}

static PyObject*
pybase64_encode(PyObject UNUSED *self, PyObject *args) {
    int add_padding = 0;
    RAII_PY_BUFFER(view);
    if (!PyArg_ParseTuple(args, "s*|p", &view, &add_padding)) return NULL;
    size_t sz = required_buffer_size_for_base64_encode(view.len);
    PyObject *ans = PyBytes_FromStringAndSize(NULL, sz);
    if (!ans) return NULL;
    base64_encode8(view.buf, view.len, (unsigned char*)PyBytes_AS_STRING(ans), &sz, add_padding);
    if (_PyBytes_Resize(&ans, sz) != 0) return NULL;
    return ans;
}

static PyObject*
pybase64_decode(PyObject UNUSED *self, PyObject *args) {
    RAII_PY_BUFFER(view);
    if (!PyArg_ParseTuple(args, "s*", &view)) return NULL;
    size_t sz = required_buffer_size_for_base64_decode(view.len);
    PyObject *ans = PyBytes_FromStringAndSize(NULL, sz);
    if (!ans) return NULL;
    base64_decode8(view.buf, view.len, (unsigned char*)PyBytes_AS_STRING(ans), &sz);
    if (_PyBytes_Resize(&ans, sz) != 0) return NULL;
    return ans;
}


static PyObject*
pyset_iutf8(PyObject UNUSED *self, PyObject *args) {
    int fd, on;
    if (!PyArg_ParseTuple(args, "ip", &fd, &on)) return NULL;
    if (!set_iutf8(fd, on & 1)) return PyErr_SetFromErrno(PyExc_OSError);
    Py_RETURN_NONE;
}

#ifdef WITH_PROFILER
static PyObject*
start_profiler(PyObject UNUSED *self, PyObject *args) {
    char *path;
    if (!PyArg_ParseTuple(args, "s", &path)) return NULL;
    ProfilerStart(path);
    Py_RETURN_NONE;
}

static PyObject*
stop_profiler(PyObject UNUSED *self, PyObject *args UNUSED) {
    ProfilerStop();
    Py_RETURN_NONE;
}
#endif

static bool
put_tty_in_raw_mode(int fd, const struct termios* termios_p, bool read_with_timeout, int optional_actions) {
    struct termios raw_termios = *termios_p;
    cfmakeraw(&raw_termios);
    if (read_with_timeout) {
        raw_termios.c_cc[VMIN] = 0; raw_termios.c_cc[VTIME] = 1;
    } else {
        raw_termios.c_cc[VMIN] = 1; raw_termios.c_cc[VTIME] = 0;
    }
    if (tcsetattr(fd, optional_actions, &raw_termios) != 0) { PyErr_SetFromErrno(PyExc_OSError); return false; }
    return true;
}

static PyObject*
open_tty(PyObject *self UNUSED, PyObject *args) {
    int read_with_timeout = 0, optional_actions = TCSAFLUSH;
    if (!PyArg_ParseTuple(args, "|pi", &read_with_timeout, &optional_actions)) return NULL;
    int flags = O_RDWR | O_CLOEXEC | O_NOCTTY;
    if (!read_with_timeout) flags |= O_NONBLOCK;
    static char ctty[L_ctermid+1];
    int fd = safe_open(ctermid(ctty), flags, 0);
    if (fd == -1) { PyErr_Format(PyExc_OSError, "Failed to open controlling terminal: %s (identified with ctermid()) with error: %s", ctty, strerror(errno)); return NULL; }
    struct termios *termios_p = calloc(1, sizeof(struct termios));
    if (!termios_p) return PyErr_NoMemory();
    if (tcgetattr(fd, termios_p) != 0) { free(termios_p); PyErr_SetFromErrno(PyExc_OSError); return NULL; }
    if (!put_tty_in_raw_mode(fd, termios_p, read_with_timeout != 0, optional_actions)) { free(termios_p); return NULL; }
    return Py_BuildValue("iN", fd, PyLong_FromVoidPtr(termios_p));
}

#define TTY_ARGS \
    PyObject *tp; int fd; int optional_actions = TCSAFLUSH; \
    if (!PyArg_ParseTuple(args, "iO!|i", &fd, &PyLong_Type, &tp, &optional_actions)) return NULL; \
    struct termios *termios_p = PyLong_AsVoidPtr(tp);

static PyObject*
normal_tty(PyObject *self UNUSED, PyObject *args) {
    TTY_ARGS
    if (tcsetattr(fd, optional_actions, termios_p) != 0) { PyErr_SetFromErrno(PyExc_OSError); return NULL; }
    Py_RETURN_NONE;
}

static PyObject*
raw_tty(PyObject *self UNUSED, PyObject *args) {
    TTY_ARGS
    if (!put_tty_in_raw_mode(fd, termios_p, false, optional_actions)) return NULL;
    Py_RETURN_NONE;
}


static PyObject*
close_tty(PyObject *self UNUSED, PyObject *args) {
    TTY_ARGS
    tcsetattr(fd, optional_actions, termios_p);  // deliberately ignore failure
    free(termios_p);
    safe_close(fd, __FILE__, __LINE__);
    Py_RETURN_NONE;
}

#undef TTY_ARGS

static PyObject*
py_shm_open(PyObject UNUSED *self, PyObject *args) {
    char *name;
    int flags, mode = 0600;
    if (!PyArg_ParseTuple(args, "si|i", &name, &flags, &mode)) return NULL;
    long fd = safe_shm_open(name, flags, mode);
    if (fd < 0) return PyErr_SetFromErrnoWithFilenameObject(PyExc_OSError, PyTuple_GET_ITEM(args, 0));
    return PyLong_FromLong(fd);
}

static PyObject*
py_shm_unlink(PyObject UNUSED *self, PyObject *args) {
    char *name;
    if (!PyArg_ParseTuple(args, "s", &name)) return NULL;
    if (shm_unlink(name) != 0) return PyErr_SetFromErrnoWithFilenameObject(PyExc_OSError, PyTuple_GET_ITEM(args, 0));
    Py_RETURN_NONE;
}

static PyObject*
wcwidth_wrap(PyObject UNUSED *self, PyObject *chr) {
    return PyLong_FromLong(wcwidth_std(PyLong_AsLong(chr)));
}

static PyObject*
locale_is_valid(PyObject *self UNUSED, PyObject *args) {
    char *name;
    if (!PyArg_ParseTuple(args, "s", &name)) return NULL;
    locale_t test_locale = newlocale(LC_ALL_MASK, name, NULL);
    if (!test_locale) { Py_RETURN_FALSE; }
    freelocale(test_locale);
    Py_RETURN_TRUE;
}

static PyObject*
py_getpeereid(PyObject *self UNUSED, PyObject *args) {
    int fd;
    if (!PyArg_ParseTuple(args, "i", &fd)) return NULL;
    uid_t euid = 0; gid_t egid = 0;
#ifdef __linux__
    struct ucred cr;
    socklen_t sz = sizeof(cr);
    if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &cr, &sz) != 0) { PyErr_SetFromErrno(PyExc_OSError); return NULL; }
    euid = cr.uid; egid = cr.gid;
#else
    if (getpeereid(fd, &euid, &egid) != 0) { PyErr_SetFromErrno(PyExc_OSError); return NULL; }
#endif
    int u = euid, g = egid;
    return Py_BuildValue("ii", u, g);
}

#include "docs_ref_map_generated.h"

static PyObject*
get_docs_ref_map(PyObject *self UNUSED, PyObject *args UNUSED) {
    return PyBytes_FromStringAndSize(docs_ref_map, sizeof(docs_ref_map));
}

static PyObject*
wrapped_kittens(PyObject *self UNUSED, PyObject *args UNUSED) {
    const char *wrapped_kitten_names = WRAPPED_KITTENS;
    PyObject *ans = PyUnicode_FromString(wrapped_kitten_names);
    if (ans == NULL) return NULL;
    PyObject *s = PyUnicode_Split(ans, NULL, -1);
    Py_DECREF(ans);
    return s;
}

static PyObject*
expand_ansi_c_escapes(PyObject *self UNUSED, PyObject *src) {
    enum { NORMAL, PREV_ESC, HEX_DIGIT, OCT_DIGIT, CONTROL_CHAR } state = NORMAL;
    if (PyUnicode_READY(src) != 0) return NULL;
    int max_num_hex_digits = 0, hex_digit_idx = 0;
    char hex_digits[16];
    Py_ssize_t idx = 0, dest_idx = 0;
    PyObject *dest = PyUnicode_New(PyUnicode_GET_LENGTH(src)*2, 1114111);
    if (dest == NULL) return NULL;
    const int kind = PyUnicode_KIND(src), dest_kind = PyUnicode_KIND(dest);
    const void *data = PyUnicode_DATA(src), *dest_data = PyUnicode_DATA(dest);
#define w(ch) { PyUnicode_WRITE(dest_kind, dest_data, dest_idx, ch); dest_idx++; }
#define write_digits(base) { hex_digits[hex_digit_idx] = 0; if (hex_digit_idx > 0) w(strtol(hex_digits, NULL, base)); hex_digit_idx = 0; state = NORMAL; }
#define add_digit(base) { hex_digits[hex_digit_idx++] = ch; if (idx >= PyUnicode_GET_LENGTH(src)) write_digits(base); }
    START_ALLOW_CASE_RANGE
    while (idx < PyUnicode_GET_LENGTH(src)) {
        Py_UCS4 ch = PyUnicode_READ(kind, data, idx); idx++;
        switch(state) {
            case NORMAL: {
                if (ch == '\\' && idx < PyUnicode_GET_LENGTH(src)) {
                    state = PREV_ESC;
                    continue;
                }
                w(ch);
            } break;
            case CONTROL_CHAR: w(ch & 0x1f); state = NORMAL; break;
            case HEX_DIGIT: {
                if (hex_digit_idx < max_num_hex_digits && (('0' <= ch && ch <= '9') || ('a' <= ch && ch <= 'f') || ('A' <= ch && ch <= 'F'))) add_digit(16)
                else { write_digits(16); idx--; }
            }; break;
            case OCT_DIGIT: {
                if ('0' <= ch && ch <= '7' && hex_digit_idx < max_num_hex_digits) add_digit(16)
                else { write_digits(8); idx--; }
            }; break;
            case PREV_ESC: {
                state = NORMAL;
                switch(ch) {
                    default: w('\\'); w(ch); break;
                    case 'a': w(7); break;
                    case 'b': w(8); break;
                    case 'c': if (idx < PyUnicode_GET_LENGTH(src)) {state = CONTROL_CHAR;} else {w('\\'); w(ch);}; break;
                    case 'e': case 'E': w(27); break;
                    case 'f': w(12); break;
                    case 'n': w(10); break;
                    case 'r': w(13); break;
                    case 't': w(9); break;
                    case 'v': w(11); break;
                    case 'x': max_num_hex_digits = 2; hex_digit_idx = 0; state = HEX_DIGIT; break;
                    case 'u': max_num_hex_digits = 4; hex_digit_idx = 0; state = HEX_DIGIT; break;
                    case 'U': max_num_hex_digits = 8; hex_digit_idx = 0; state = HEX_DIGIT; break;
                    case '0' ... '7': max_num_hex_digits = 3; hex_digits[0] = ch; hex_digit_idx = 1; state = OCT_DIGIT; break;
                    case '\\': w('\\'); break;
                    case '?': w('?'); break;
                    case '"': w('"'); break;
                    case '\'': w('\''); break;
                }
            } break;
        }
    }
#undef add_digit
#undef write_digits
#undef w
    END_ALLOW_CASE_RANGE
    PyObject *ans = PyUnicode_FromKindAndData(dest_kind, dest_data, dest_idx);
    Py_DECREF(dest);
    return ans;
}

static PyMethodDef module_methods[] = {
    {"wcwidth", (PyCFunction)wcwidth_wrap, METH_O, ""},
    {"expand_ansi_c_escapes", (PyCFunction)expand_ansi_c_escapes, METH_O, ""},
    {"get_docs_ref_map", (PyCFunction)get_docs_ref_map, METH_NOARGS, ""},
    {"getpeereid", (PyCFunction)py_getpeereid, METH_VARARGS, ""},
    {"wcswidth", (PyCFunction)wcswidth_std, METH_O, ""},
    {"unicode_database_version", (PyCFunction)unicode_database_version, METH_NOARGS, ""},
    {"open_tty", open_tty, METH_VARARGS, ""},
    {"normal_tty", normal_tty, METH_VARARGS, ""},
    {"raw_tty", raw_tty, METH_VARARGS, ""},
    {"close_tty", close_tty, METH_VARARGS, ""},
    {"set_iutf8_fd", (PyCFunction)pyset_iutf8, METH_VARARGS, ""},
    {"base64_encode", (PyCFunction)pybase64_encode, METH_VARARGS, ""},
    {"base64_decode", (PyCFunction)pybase64_decode, METH_VARARGS, ""},
    {"thread_write", (PyCFunction)cm_thread_write, METH_VARARGS, ""},
    {"parse_bytes", (PyCFunction)parse_bytes, METH_VARARGS, ""},
    {"parse_bytes_dump", (PyCFunction)parse_bytes_dump, METH_VARARGS, ""},
    {"redirect_std_streams", (PyCFunction)redirect_std_streams, METH_VARARGS, ""},
    {"locale_is_valid", (PyCFunction)locale_is_valid, METH_VARARGS, ""},
    {"shm_open", (PyCFunction)py_shm_open, METH_VARARGS, ""},
    {"shm_unlink", (PyCFunction)py_shm_unlink, METH_VARARGS, ""},
    {"wrapped_kitten_names", (PyCFunction)wrapped_kittens, METH_NOARGS, ""},
#ifdef __APPLE__
    METHODB(user_cache_dir, METH_NOARGS),
    METHODB(process_group_map, METH_NOARGS),
#endif
#ifdef WITH_PROFILER
    {"start_profiler", (PyCFunction)start_profiler, METH_VARARGS, ""},
    {"stop_profiler", (PyCFunction)stop_profiler, METH_NOARGS, ""},
#endif
    {NULL, NULL, 0, NULL}        /* Sentinel */
};


static struct PyModuleDef module = {
    .m_base = PyModuleDef_HEAD_INIT,
    .m_name = "fast_data_types",   /* name of module */
    .m_doc = NULL,
    .m_size = -1,
    .m_methods = module_methods
};


extern int init_LineBuf(PyObject *);
extern int init_HistoryBuf(PyObject *);
extern int init_Cursor(PyObject *);
extern int init_DiskCache(PyObject *);
extern bool init_child_monitor(PyObject *);
extern int init_Line(PyObject *);
extern int init_ColorProfile(PyObject *);
extern int init_Screen(PyObject *);
extern bool init_fontconfig_library(PyObject*);
extern bool init_crypto_library(PyObject*);
extern bool init_desktop(PyObject*);
extern bool init_fonts(PyObject*);
extern bool init_glfw(PyObject *m);
extern bool init_child(PyObject *m);
extern bool init_state(PyObject *module);
extern bool init_keys(PyObject *module);
extern bool init_graphics(PyObject *module);
extern bool init_shaders(PyObject *module);
extern bool init_mouse(PyObject *module);
extern bool init_kittens(PyObject *module);
extern bool init_logging(PyObject *module);
extern bool init_png_reader(PyObject *module);
extern bool init_utmp(PyObject *module);
extern bool init_loop_utils(PyObject *module);
#ifdef __APPLE__
extern int init_CoreText(PyObject *);
extern bool init_cocoa(PyObject *module);
extern bool init_macos_process_info(PyObject *module);
#else
extern bool init_freetype_library(PyObject*);
extern bool init_freetype_render_ui_text(PyObject*);
#endif

static unsigned
shift_to_first_set_bit(CellAttrs x) {
    unsigned num_of_bits = 8 * sizeof(x.val);
    unsigned ans = 0;
    while (num_of_bits--) {
        if (x.val & 1) return ans;
        x.val >>= 1;
        ans++;
    }
    return ans;
}

EXPORTED PyMODINIT_FUNC
PyInit_fast_data_types(void) {
    PyObject *m;
    if (sizeof(CellAttrs) != 2u) {
        PyErr_SetString(PyExc_RuntimeError, "Size of CellAttrs is not 2 on this platform");
        return NULL;
    }

    m = PyModule_Create(&module);
    if (m == NULL) return NULL;
    if (Py_AtExit(run_at_exit_cleanup_functions) != 0) {
        PyErr_SetString(PyExc_RuntimeError, "Failed to register the atexit cleanup handler");
        return NULL;
    }
    init_monotonic();

    if (!init_logging(m)) return NULL;
    if (!init_LineBuf(m)) return NULL;
    if (!init_HistoryBuf(m)) return NULL;
    if (!init_Line(m)) return NULL;
    if (!init_Cursor(m)) return NULL;
    if (!init_DiskCache(m)) return NULL;
    if (!init_child_monitor(m)) return NULL;
    if (!init_ColorProfile(m)) return NULL;
    if (!init_Screen(m)) return NULL;
    if (!init_glfw(m)) return NULL;
    if (!init_child(m)) return NULL;
    if (!init_state(m)) return NULL;
    if (!init_keys(m)) return NULL;
    if (!init_graphics(m)) return NULL;
    if (!init_shaders(m)) return NULL;
    if (!init_mouse(m)) return NULL;
    if (!init_kittens(m)) return NULL;
    if (!init_png_reader(m)) return NULL;
#ifdef __APPLE__
    if (!init_macos_process_info(m)) return NULL;
    if (!init_CoreText(m)) return NULL;
    if (!init_cocoa(m)) return NULL;
#else
    if (!init_freetype_library(m)) return NULL;
    if (!init_fontconfig_library(m)) return NULL;
    if (!init_desktop(m)) return NULL;
    if (!init_freetype_render_ui_text(m)) return NULL;
#endif
    if (!init_fonts(m)) return NULL;
    if (!init_utmp(m)) return NULL;
    if (!init_loop_utils(m)) return NULL;
    if (!init_crypto_library(m)) return NULL;

    CellAttrs a;
#define s(name, attr) { a.val = 0; a.attr = 1; PyModule_AddIntConstant(m, #name, shift_to_first_set_bit(a)); }
    s(BOLD, bold); s(ITALIC, italic); s(REVERSE, reverse); s(MARK, mark);
    s(STRIKETHROUGH, strike); s(DIM, dim); s(DECORATION, decoration);
#undef s
    PyModule_AddIntConstant(m, "MARK_MASK", MARK_MASK);
    PyModule_AddIntConstant(m, "DECORATION_MASK", DECORATION_MASK);
    PyModule_AddIntConstant(m, "NUM_UNDERLINE_STYLES", NUM_UNDERLINE_STYLES);
    PyModule_AddStringMacro(m, ERROR_PREFIX);
#ifdef KITTY_VCS_REV
    PyModule_AddStringMacro(m, KITTY_VCS_REV);
#endif
    PyModule_AddIntMacro(m, CURSOR_BLOCK);
    PyModule_AddIntMacro(m, CURSOR_BEAM);
    PyModule_AddIntMacro(m, CURSOR_UNDERLINE);
    PyModule_AddIntMacro(m, NO_CURSOR_SHAPE);
    PyModule_AddIntMacro(m, DECAWM);
    PyModule_AddIntMacro(m, DECCOLM);
    PyModule_AddIntMacro(m, DECOM);
    PyModule_AddIntMacro(m, IRM);
    PyModule_AddIntMacro(m, CSI);
    PyModule_AddIntMacro(m, DCS);
    PyModule_AddIntMacro(m, APC);
    PyModule_AddIntMacro(m, OSC);
    PyModule_AddIntMacro(m, FILE_TRANSFER_CODE);
#ifdef __APPLE__
    // Apple says its SHM_NAME_MAX but SHM_NAME_MAX is not actually declared in typical CrApple style.
    // This value is based on experimentation and from qsharedmemory.cpp in Qt
    PyModule_AddIntConstant(m, "SHM_NAME_MAX", 30);
#else
    // FreeBSD's man page says this is 1023. Linux says its PATH_MAX.
    PyModule_AddIntConstant(m, "SHM_NAME_MAX", MIN(1023, PATH_MAX));
#endif

    return m;
}