#include "cache.h"
#include "column.h"
#include "string-list.h"
#include "parse-options.h"
#include "run-command.h"
#include "utf8.h"

#define XY2LINEAR(d, x, y) (COL_LAYOUT((d)->colopts) == COL_COLUMN ? \
                            (x) * (d)->rows + (y) : \
                            (y) * (d)->cols + (x))

struct column_data {
        const struct string_list *list;
        unsigned int colopts;
        struct column_options opts;

        int rows, cols;
        int *len;               /* cell length */
        int *width;           /* index to the longest row in column */
};

/* return length of 's' in letters, ANSI escapes stripped */
static int item_length(unsigned int colopts, const char *s)
{
        int len, i = 0;
        struct strbuf str = STRBUF_INIT;

        strbuf_addstr(&str, s);
        while ((s = strstr(str.buf + i, "\033[")) != NULL) {
                int len = strspn(s + 2, "0123456789;");
                i = s - str.buf;
                strbuf_remove(&str, i, len + 3); /* \033[<len><func char> */
        }
        len = utf8_strwidth(str.buf);
        strbuf_release(&str);
        return len;
}

/*
 * Calculate cell width, rows and cols for a table of equal cells, given
 * table width and how many spaces between cells.
 */
static void layout(struct column_data *data, int *width)
{
        int i;

        *width = 0;
        for (i = 0; i < data->list->nr; i++)
                if (*width < data->len[i])
                        *width = data->len[i];

        *width += data->opts.padding;

        data->cols = (data->opts.width - strlen(data->opts.indent)) / *width;
        if (data->cols == 0)
                data->cols = 1;

        data->rows = DIV_ROUND_UP(data->list->nr, data->cols);
}

static void compute_column_width(struct column_data *data)
{
        int i, x, y;
        for (x = 0; x < data->cols; x++) {
                data->width[x] = XY2LINEAR(data, x, 0);
                for (y = 0; y < data->rows; y++) {
                        i = XY2LINEAR(data, x, y);
                        if (i < data->list->nr &&
                            data->len[data->width[x]] < data->len[i])
                                data->width[x] = i;
                }
        }
}

/*
 * Shrink all columns by shortening them one row each time (and adding
 * more columns along the way). Hopefully the longest cell will be
 * moved to the next column, column is shrunk so we have more space
 * for new columns. The process ends when the whole thing no longer
 * fits in data->total_width.
 */
static void shrink_columns(struct column_data *data)
{
        data->width = xrealloc(data->width,
                               sizeof(*data->width) * data->cols);
        while (data->rows > 1) {
                int x, total_width, cols, rows;
                rows = data->rows;
                cols = data->cols;

                data->rows--;
                data->cols = DIV_ROUND_UP(data->list->nr, data->rows);
                if (data->cols != cols)
                        data->width = xrealloc(data->width,
                                               sizeof(*data->width) * data->cols);
                compute_column_width(data);

                total_width = strlen(data->opts.indent);
                for (x = 0; x < data->cols; x++) {
                        total_width += data->len[data->width[x]];
                        total_width += data->opts.padding;
                }
                if (total_width > data->opts.width) {
                        data->rows = rows;
                        data->cols = cols;
                        break;
                }
        }
        compute_column_width(data);
}

/* Display without layout when not enabled */
static void display_plain(const struct string_list *list,
                          const char *indent, const char *nl)
{
        int i;

        for (i = 0; i < list->nr; i++)
                printf("%s%s%s", indent, list->items[i].string, nl);
}

/* Print a cell to stdout with all necessary leading/traling space */
static int display_cell(struct column_data *data, int initial_width,
                        const char *empty_cell, int x, int y)
{
        int i, len, newline;

        i = XY2LINEAR(data, x, y);
        if (i >= data->list->nr)
                return -1;

        len = data->len[i];
        if (data->width && data->len[data->width[x]] < initial_width) {
                /*
                 * empty_cell has initial_width chars, if real column
                 * is narrower, increase len a bit so we fill less
                 * space.
                 */
                len += initial_width - data->len[data->width[x]];
                len -= data->opts.padding;
        }

        if (COL_LAYOUT(data->colopts) == COL_COLUMN)
                newline = i + data->rows >= data->list->nr;
        else
                newline = x == data->cols - 1 || i == data->list->nr - 1;

        printf("%s%s%s",
               x == 0 ? data->opts.indent : "",
               data->list->items[i].string,
               newline ? data->opts.nl : empty_cell + len);
        return 0;
}

/* Display COL_COLUMN or COL_ROW */
static void display_table(const struct string_list *list,
                          unsigned int colopts,
                          const struct column_options *opts)
{
        struct column_data data;
        int x, y, i, initial_width;
        char *empty_cell;

        memset(&data, 0, sizeof(data));
        data.list = list;
        data.colopts = colopts;
        data.opts = *opts;

        data.len = xmalloc(sizeof(*data.len) * list->nr);
        for (i = 0; i < list->nr; i++)
                data.len[i] = item_length(colopts, list->items[i].string);

        layout(&data, &initial_width);

        if (colopts & COL_DENSE)
                shrink_columns(&data);

        empty_cell = xmalloc(initial_width + 1);
        memset(empty_cell, ' ', initial_width);
        empty_cell[initial_width] = '\0';
        for (y = 0; y < data.rows; y++) {
                for (x = 0; x < data.cols; x++)
                        if (display_cell(&data, initial_width, empty_cell, x, y))
                                break;
        }

        free(data.len);
        free(data.width);
        free(empty_cell);
}

void print_columns(const struct string_list *list, unsigned int colopts,
                   const struct column_options *opts)
{
        struct column_options nopts;

        if (!list->nr)
                return;
        assert((colopts & COL_ENABLE_MASK) != COL_AUTO);

        memset(&nopts, 0, sizeof(nopts));
        nopts.indent = opts && opts->indent ? opts->indent : "";
        nopts.nl = opts && opts->nl ? opts->nl : "\n";
        nopts.padding = opts ? opts->padding : 1;
        nopts.width = opts && opts->width ? opts->width : term_columns() - 1;
        if (!column_active(colopts)) {
                display_plain(list, "", "\n");
                return;
        }
        switch (COL_LAYOUT(colopts)) {
        case COL_PLAIN:
                display_plain(list, nopts.indent, nopts.nl);
                break;
        case COL_ROW:
        case COL_COLUMN:
                display_table(list, colopts, &nopts);
                break;
        default:
                die("BUG: invalid layout mode %d", COL_LAYOUT(colopts));
        }
}

int finalize_colopts(unsigned int *colopts, int stdout_is_tty)
{
        if ((*colopts & COL_ENABLE_MASK) == COL_AUTO) {
                if (stdout_is_tty < 0)
                        stdout_is_tty = isatty(1);
                *colopts &= ~COL_ENABLE_MASK;
                if (stdout_is_tty)
                        *colopts |= COL_ENABLED;
        }
        return 0;
}

struct colopt {
        const char *name;
        unsigned int value;
        unsigned int mask;
};

#define LAYOUT_SET 1
#define ENABLE_SET 2

static int parse_option(const char *arg, int len, unsigned int *colopts,
                        int *group_set)
{
        struct colopt opts[] = {
                { "always", COL_ENABLED,  COL_ENABLE_MASK },
                { "never",  COL_DISABLED, COL_ENABLE_MASK },
                { "auto",   COL_AUTO,     COL_ENABLE_MASK },
                { "plain",  COL_PLAIN,    COL_LAYOUT_MASK },
                { "column", COL_COLUMN,   COL_LAYOUT_MASK },
                { "row",    COL_ROW,      COL_LAYOUT_MASK },
                { "dense",  COL_DENSE,    0 },
        };
        int i;

        for (i = 0; i < ARRAY_SIZE(opts); i++) {
                int set = 1, arg_len = len, name_len;
                const char *arg_str = arg;

                if (!opts[i].mask) {
                        if (arg_len > 2 && !strncmp(arg_str, "no", 2)) {
                                arg_str += 2;
                                arg_len -= 2;
                                set = 0;
                        }
                }

                name_len = strlen(opts[i].name);
                if (arg_len != name_len ||
                    strncmp(arg_str, opts[i].name, name_len))
                        continue;

                switch (opts[i].mask) {
                case COL_ENABLE_MASK:
                        *group_set |= ENABLE_SET;
                        break;
                case COL_LAYOUT_MASK:
                        *group_set |= LAYOUT_SET;
                        break;
                }

                if (opts[i].mask)
                        *colopts = (*colopts & ~opts[i].mask) | opts[i].value;
                else {
                        if (set)
                                *colopts |= opts[i].value;
                        else
                                *colopts &= ~opts[i].value;
                }
                return 0;
        }

        return error("unsupported option '%s'", arg);
}

static int parse_config(unsigned int *colopts, const char *value)
{
        const char *sep = " ,";
        int group_set = 0;

        while (*value) {
                int len = strcspn(value, sep);
                if (len) {
                        if (parse_option(value, len, colopts, &group_set))
                                return -1;

                        value += len;
                }
                value += strspn(value, sep);
        }
        /*
         * Setting layout implies "always" if neither always, never
         * nor auto is specified.
         *
         * Current value in COL_ENABLE_MASK is disregarded. This means if
         * you set column.ui = auto and pass --column=row, then "auto"
         * will become "always".
         */
        if ((group_set & LAYOUT_SET) && !(group_set & ENABLE_SET))
                *colopts = (*colopts & ~COL_ENABLE_MASK) | COL_ENABLED;
        return 0;
}

static int column_config(const char *var, const char *value,
                         const char *key, unsigned int *colopts)
{
        if (!value)
                return config_error_nonbool(var);
        if (parse_config(colopts, value))
                return error("invalid column.%s mode %s", key, value);
        return 0;
}

int git_column_config(const char *var, const char *value,
                      const char *command, unsigned int *colopts)
{
        const char *it = skip_prefix(var, "column.");
        if (!it)
                return 0;

        if (!strcmp(it, "ui"))
                return column_config(var, value, "ui", colopts);

        if (command && !strcmp(it, command))
                return column_config(var, value, it, colopts);

        return 0;
}

int parseopt_column_callback(const struct option *opt,
                             const char *arg, int unset)
{
        unsigned int *colopts = opt->value;
        *colopts |= COL_PARSEOPT;
        *colopts &= ~COL_ENABLE_MASK;
        if (unset)              /* --no-column == never */
                return 0;
        /* --column == always unless "arg" states otherwise */
        *colopts |= COL_ENABLED;
        if (arg)
                return parse_config(colopts, arg);

        return 0;
}

static int fd_out = -1;
static struct child_process column_process;

int run_column_filter(int colopts, const struct column_options *opts)
{
        const char *av[10];
        int ret, ac = 0;
        struct strbuf sb_colopt  = STRBUF_INIT;
        struct strbuf sb_width   = STRBUF_INIT;
        struct strbuf sb_padding = STRBUF_INIT;

        if (fd_out != -1)
                return -1;

        av[ac++] = "column";
        strbuf_addf(&sb_colopt, "--raw-mode=%d", colopts);
        av[ac++] = sb_colopt.buf;
        if (opts && opts->width) {
                strbuf_addf(&sb_width, "--width=%d", opts->width);
                av[ac++] = sb_width.buf;
        }
        if (opts && opts->indent) {
                av[ac++] = "--indent";
                av[ac++] = opts->indent;
        }
        if (opts && opts->padding) {
                strbuf_addf(&sb_padding, "--padding=%d", opts->padding);
                av[ac++] = sb_padding.buf;
        }
        av[ac] = NULL;

        fflush(stdout);
        memset(&column_process, 0, sizeof(column_process));
        column_process.in = -1;
        column_process.out = dup(1);
        column_process.git_cmd = 1;
        column_process.argv = av;

        ret = start_command(&column_process);

        strbuf_release(&sb_colopt);
        strbuf_release(&sb_width);
        strbuf_release(&sb_padding);

        if (ret)
                return -2;

        fd_out = dup(1);
        close(1);
        dup2(column_process.in, 1);
        close(column_process.in);
        return 0;
}

int stop_column_filter(void)
{
        if (fd_out == -1)
                return -1;

        fflush(stdout);
        close(1);
        finish_command(&column_process);
        dup2(fd_out, 1);
        close(fd_out);
        fd_out = -1;
        return 0;
}