/**
 * Copyright (c) 2007-2012, Timothy Stack
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * * Neither the name of Timothy Stack nor the names of its contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @file hist_source.hh
 */

#ifndef __hist_source_hh
#define __hist_source_hh

#include <math.h>

#include <map>
#include <limits>
#include <string>
#include <vector>

#include "lnav_log.hh"
#include "strong_int.hh"
#include "textview_curses.hh"

typedef float bucket_count_t;

/** Type for indexes into a group of buckets. */
STRONG_INT_TYPE(int, bucket_group);

/** Type used to differentiate values added to the same row in the histogram */
STRONG_INT_TYPE(int, bucket_type);

/**
 * A text source that displays data as a histogram using horizontal bars.  Data
 * is added to the histogram using the add_value() method.  Once all of the
 * values have been added, the analyze() method needs to be called to analyze
 * the data so that it can be displayed.
 *
 * For example, if the values (7, 3, 4, 2) were added, they would be displayed
 * like so:
 *
 *   ******
 *   ***
 *   ****
 *   **
 */
class hist_source
    : public text_sub_source {
public:
    typedef std::map<bucket_type_t, bucket_count_t> bucket_t;

    /**
     * Source for labels on each bucket and group.
     */
    class label_source {
public:
        virtual ~label_source() { };

        virtual void hist_label_for_group(int group,
                                          std::string &label_out) { };

        virtual void hist_label_for_bucket(int bucket_start_value,
                                           const bucket_t &bucket,
                                           std::string &label_out) { };

        virtual void hist_attrs_for_bucket(int bucket_start_value,
                                           const bucket_t &bucket,
                                           string_attrs_t &sa) { };
    };

    hist_source();
    virtual ~hist_source() { };

    void set_bucket_size(unsigned int bs)
    {
        require(bs > 0);

        this->hs_bucket_size = bs;
    };
    unsigned int get_bucket_size(void) const { return this->hs_bucket_size; };

    void set_group_size(unsigned int gs)
    {
        require(gs > 0);
        this->hs_group_size = gs;
    };
    unsigned int get_group_size(void) const { return this->hs_group_size; };

    void set_label_source(label_source *hls)
    {
        this->hs_label_source = hls;
    }

    label_source *get_label_source(void)
    {
        return this->hs_label_source;
    };

    int buckets_per_group(void) const
    {
        return this->hs_group_size / this->hs_bucket_size;
    };

    void clear(void) {
        this->hs_groups.clear();
        this->hs_bucket_stats.clear();
    };

    size_t text_line_count()
    {
        return (this->buckets_per_group() + 1) * this->hs_groups.size();
    };

    void set_role_for_type(bucket_type_t bt, view_colors::role_t role)
    {
        this->hs_type2role[bt] = role;
    };
    const view_colors::role_t &get_role_for_type(bucket_type_t bt)
    {
        return this->hs_type2role[bt];
    };

    void text_value_for_line(textview_curses &tc,
                             int row,
                             std::string &value_out,
                             bool no_scrub);
    void text_attrs_for_line(textview_curses &tc,
                             int row,
                             string_attrs_t &value_out);

    size_t text_size_for_line(textview_curses &tc, int row, bool raw) {
        return 0;
    };

    int value_for_row(vis_line_t row)
    {
        int grow   = row / (this->buckets_per_group() + 1);
        int brow   = row % (this->buckets_per_group() + 1);
        int retval = 0;

        if (!this->hs_groups.empty()) {
            std::map<bucket_group_t, bucket_array_t>::const_iterator iter;

            iter = this->hs_groups.begin();
            std::advance(iter, grow);

            bucket_group_t bg = iter->first;

            if (brow > 0) {
                brow -= 1;
            }
            retval =
                (bg * this->hs_group_size) + (brow * this->hs_bucket_size);
        }

        return retval;
    };

    vis_line_t row_for_value(int value)
    {
        vis_line_t retval;

        if (!this->hs_groups.empty()) {
            bucket_group_t bg(value / this->hs_group_size);

            std::map<bucket_group_t, bucket_array_t>::iterator lb;

            lb = this->hs_groups.lower_bound(bg);
            retval = vis_line_t(distance(this->hs_groups.begin(), lb) *
                                (this->buckets_per_group() + 1));
            retval += vis_line_t(1 +
                                 (value % this->hs_group_size) /
                                 this->hs_bucket_size);
        }

        return retval;
    };

    /**
     * Add a value to the histogram.
     *
     * @param value The row in the histogram.
     * @param bt The type of data.
     * @param amount The amount to add to this row in the histogram.
     */
    void add_value(unsigned int value,
                   bucket_type_t bt,
                   bucket_count_t amount = 1.0);

    void add_empty_value(unsigned int value)
    {
        bucket_group_t bg;

        bg = bucket_group_t(value / this->hs_group_size);

        bucket_array_t &ba = this->hs_groups[bg];

        if (ba.empty()) {
            ba.resize(this->buckets_per_group());
        }
    };

    std::vector<bucket_type_t> &get_displayed_buckets() {
        return this->hs_displayed_buckets;
    };

    bool is_bucket_graphed(bucket_type_t type) const {
        return (this->hs_displayed_buckets.empty() ||
                std::find(this->hs_displayed_buckets.begin(),
                          this->hs_displayed_buckets.end(),
                          type) != this->hs_displayed_buckets.end());
    };

protected:
    typedef std::vector<bucket_t> bucket_array_t;

    struct bucket_stats_t {
        bucket_stats_t() :
            bs_min_count(std::numeric_limits<bucket_count_t>::max()),
            bs_max_count(0)
        {
        };

        void merge(const bucket_stats_t &rhs) {
            this->bs_min_count = std::min(this->bs_min_count, rhs.bs_min_count);
            this->bs_max_count += rhs.bs_max_count;
        };

        bucket_count_t width() const {
            return fabs(this->bs_max_count - this->bs_min_count);
        };

        bucket_count_t bs_min_count;
        bucket_count_t bs_max_count;
    };

    std::map<bucket_type_t, view_colors::role_t> hs_type2role;

    std::map<bucket_group_t, bucket_array_t> hs_groups;
    std::map<bucket_type_t, bucket_stats_t> hs_bucket_stats;

    unsigned int   hs_bucket_size; /* hours */
    unsigned int   hs_group_size;  /* days */
    label_source *hs_label_source;

    bucket_t *hs_token_bucket;
    std::vector<bucket_type_t> hs_displayed_buckets;
};
#endif