/*
This tool is part of the WhiteboxTools geospatial analysis library.
Authors: Dr. John Lindsay
Created: 26/06/2017
Last Modified: 30/01/2020
License: MIT
*/

use whitebox_raster::*;
use crate::tools::*;
use num_cpus;
use std::collections::VecDeque;
use std::env;
use std::f64;
use std::f64::consts::PI;
use std::io::{Error, ErrorKind};
use std::path;
use std::sync::mpsc;
use std::sync::Arc;
use std::thread;

/// This tool performs a range filter on an input image (`--input`). A range filter assigns to each cell in the output grid
/// (`--output`) the range (maximum - minimum) of the values contained within a moving window centred on each grid cell.
///
/// Neighbourhood size, or filter size, is specified in the x and y dimensions using the `--filterx` and `--filtery`
/// flags. These dimensions should be odd, positive integer values (e.g. 3, 5, 7, 9, etc.).
///
/// # See Also
/// `TotalFilter`
pub struct RangeFilter {
    name: String,
    description: String,
    toolbox: String,
    parameters: Vec<ToolParameter>,
    example_usage: String,
}

impl RangeFilter {
    pub fn new() -> RangeFilter {
        // public constructor
        let name = "RangeFilter".to_string();
        let toolbox = "Image Processing Tools/Filters".to_string();
        let description = "Assigns each cell in the output grid the range of values in a moving window centred on each grid cell in the input raster.".to_string();

        let mut parameters = vec![];
        parameters.push(ToolParameter {
            name: "Input File".to_owned(),
            flags: vec!["-i".to_owned(), "--input".to_owned()],
            description: "Input raster file.".to_owned(),
            parameter_type: ParameterType::ExistingFile(ParameterFileType::Raster),
            default_value: None,
            optional: false,
        });

        parameters.push(ToolParameter {
            name: "Output File".to_owned(),
            flags: vec!["-o".to_owned(), "--output".to_owned()],
            description: "Output raster file.".to_owned(),
            parameter_type: ParameterType::NewFile(ParameterFileType::Raster),
            default_value: None,
            optional: false,
        });

        parameters.push(ToolParameter {
            name: "Filter X-Dimension".to_owned(),
            flags: vec!["--filterx".to_owned()],
            description: "Size of the filter kernel in the x-direction.".to_owned(),
            parameter_type: ParameterType::Integer,
            default_value: Some("11".to_owned()),
            optional: true,
        });

        parameters.push(ToolParameter {
            name: "Filter Y-Dimension".to_owned(),
            flags: vec!["--filtery".to_owned()],
            description: "Size of the filter kernel in the y-direction.".to_owned(),
            parameter_type: ParameterType::Integer,
            default_value: Some("11".to_owned()),
            optional: true,
        });

        let sep: String = path::MAIN_SEPARATOR.to_string();
        let p = format!("{}", env::current_dir().unwrap().display());
        let e = format!("{}", env::current_exe().unwrap().display());
        let mut short_exe = e
            .replace(&p, "")
            .replace(".exe", "")
            .replace(".", "")
            .replace(&sep, "");
        if e.contains(".exe") {
            short_exe += ".exe";
        }
        let usage = format!(
            ">>.*{} -r={} -v --wd=\"*path*to*data*\" -i=image.tif -o=output.tif --filter=25",
            short_exe, name
        )
        .replace("*", &sep);

        RangeFilter {
            name: name,
            description: description,
            toolbox: toolbox,
            parameters: parameters,
            example_usage: usage,
        }
    }
}

impl WhiteboxTool for RangeFilter {
    fn get_source_file(&self) -> String {
        String::from(file!())
    }

    fn get_tool_name(&self) -> String {
        self.name.clone()
    }

    fn get_tool_description(&self) -> String {
        self.description.clone()
    }

    fn get_tool_parameters(&self) -> String {
        let mut s = String::from("{\"parameters\": [");
        for i in 0..self.parameters.len() {
            if i < self.parameters.len() - 1 {
                s.push_str(&(self.parameters[i].to_string()));
                s.push_str(",");
            } else {
                s.push_str(&(self.parameters[i].to_string()));
            }
        }
        s.push_str("]}");
        s
    }

    fn get_example_usage(&self) -> String {
        self.example_usage.clone()
    }

    fn get_toolbox(&self) -> String {
        self.toolbox.clone()
    }

    fn run<'a>(
        &self,
        args: Vec<String>,
        working_directory: &'a str,
        verbose: bool,
    ) -> Result<(), Error> {
        let mut input_file = String::new();
        let mut output_file = String::new();
        let mut filter_size_x = 11usize;
        let mut filter_size_y = 11usize;
        if args.len() == 0 {
            return Err(Error::new(
                ErrorKind::InvalidInput,
                "Tool run with no parameters.",
            ));
        }
        for i in 0..args.len() {
            let mut arg = args[i].replace("\"", "");
            arg = arg.replace("\'", "");
            let cmd = arg.split("="); // in case an equals sign was used
            let vec = cmd.collect::<Vec<&str>>();
            let mut keyval = false;
            if vec.len() > 1 {
                keyval = true;
            }
            let flag_val = vec[0].to_lowercase().replace("--", "-");
            if flag_val == "-i" || flag_val == "-input" {
                if keyval {
                    input_file = vec[1].to_string();
                } else {
                    input_file = args[i + 1].to_string();
                }
            } else if flag_val == "-o" || flag_val == "-output" {
                if keyval {
                    output_file = vec[1].to_string();
                } else {
                    output_file = args[i + 1].to_string();
                }
            } else if flag_val == "-filter" {
                if keyval {
                    filter_size_x = vec[1]
                        .to_string()
                        .parse::<f32>()
                        .expect(&format!("Error parsing {}", flag_val))
                        as usize;
                } else {
                    filter_size_x = args[i + 1]
                        .to_string()
                        .parse::<f32>()
                        .expect(&format!("Error parsing {}", flag_val))
                        as usize;
                }
                filter_size_y = filter_size_x;
            } else if flag_val == "-filterx" {
                if keyval {
                    filter_size_x = vec[1]
                        .to_string()
                        .parse::<f32>()
                        .expect(&format!("Error parsing {}", flag_val))
                        as usize;
                } else {
                    filter_size_x = args[i + 1]
                        .to_string()
                        .parse::<f32>()
                        .expect(&format!("Error parsing {}", flag_val))
                        as usize;
                }
            } else if flag_val == "-filtery" {
                if keyval {
                    filter_size_y = vec[1]
                        .to_string()
                        .parse::<f32>()
                        .expect(&format!("Error parsing {}", flag_val))
                        as usize;
                } else {
                    filter_size_y = args[i + 1]
                        .to_string()
                        .parse::<f32>()
                        .expect(&format!("Error parsing {}", flag_val))
                        as usize;
                }
            }
        }

        if verbose {
            println!("***************{}", "*".repeat(self.get_tool_name().len()));
            println!("* Welcome to {} *", self.get_tool_name());
            println!("***************{}", "*".repeat(self.get_tool_name().len()));
        }

        let sep: String = path::MAIN_SEPARATOR.to_string();

        if filter_size_x < 3 {
            filter_size_x = 3;
        }
        if filter_size_y < 3 {
            filter_size_y = 3;
        }

        // The filter dimensions must be odd numbers such that there is a middle pixel
        if (filter_size_x as f64 / 2f64).floor() == (filter_size_x as f64 / 2f64) {
            filter_size_x += 1;
        }
        if (filter_size_y as f64 / 2f64).floor() == (filter_size_y as f64 / 2f64) {
            filter_size_y += 1;
        }

        // let (mut z, mut z_n): (f64, f64);
        let midpoint_x = (filter_size_x as f64 / 2f64).floor() as isize;
        let midpoint_y = (filter_size_y as f64 / 2f64).floor() as isize;
        let mut progress: usize;
        let mut old_progress: usize = 1;

        if !input_file.contains(&sep) && !input_file.contains("/") {
            input_file = format!("{}{}", working_directory, input_file);
        }
        if !output_file.contains(&sep) && !output_file.contains("/") {
            output_file = format!("{}{}", working_directory, output_file);
        }

        if verbose {
            println!("Reading data...")
        };

        let input = Arc::new(Raster::new(&input_file, "r")?);

        let start = Instant::now();

        let is_rgb_image = if input.configs.data_type == DataType::RGB24
            || input.configs.data_type == DataType::RGBA32
            || input.configs.photometric_interp == PhotometricInterpretation::RGB
        {
            true
        } else {
            false
        };

        let rows = input.configs.rows as isize;
        let columns = input.configs.columns as isize;
        let nodata = input.configs.nodata;

        let mut output = Raster::initialize_using_file(&output_file, &input);

        let mut num_procs = num_cpus::get() as isize;
        let configs = whitebox_common::configs::get_configs()?;
        let max_procs = configs.max_procs;
        if max_procs > 0 && max_procs < num_procs {
            num_procs = max_procs;
        }
        let (tx, rx) = mpsc::channel();
        for tid in 0..num_procs {
            let input = input.clone();
            let tx1 = tx.clone();
            thread::spawn(move || {
                let input_fn: Box<dyn Fn(isize, isize) -> f64> = if !is_rgb_image {
                    Box::new(|row: isize, col: isize| -> f64 { input.get_value(row, col) })
                } else {
                    Box::new(|row: isize, col: isize| -> f64 {
                        let value = input.get_value(row, col);
                        if value != nodata {
                            return value2i(value);
                        }
                        nodata
                    })
                };

                let output_fn: Box<dyn Fn(isize, isize, f64) -> f64> = if !is_rgb_image {
                    // simply return the value.
                    Box::new(|_: isize, _: isize, value: f64| -> f64 { value })
                } else {
                    // convert it back into an rgb value, using the modified intensity value.
                    Box::new(|row: isize, col: isize, value: f64| -> f64 {
                        if value != nodata {
                            let (h, s, _) = value2hsi(input.get_value(row, col));
                            return hsi2value(h, s, value);
                        }
                        nodata
                    })
                };
                let (mut z_n, mut z): (f64, f64);
                let (mut min_val, mut max_val): (f64, f64);
                let (mut start_col, mut end_col, mut start_row, mut end_row): (
                    isize,
                    isize,
                    isize,
                    isize,
                );
                for row in (0..rows).filter(|r| r % num_procs == tid) {
                    let mut filter_min_vals: VecDeque<f64> = VecDeque::with_capacity(filter_size_x);
                    let mut filter_max_vals: VecDeque<f64> = VecDeque::with_capacity(filter_size_x);
                    start_row = row - midpoint_y;
                    end_row = row + midpoint_y;
                    let mut data = vec![nodata; columns as usize];
                    for col in 0..columns {
                        if col > 0 {
                            filter_min_vals.pop_front();
                            filter_max_vals.pop_front();
                            min_val = f64::INFINITY;
                            max_val = f64::NEG_INFINITY;
                            for row2 in start_row..end_row + 1 {
                                z_n = input_fn(row2, col + midpoint_x);
                                if z_n != nodata {
                                    if z_n < min_val {
                                        min_val = z_n;
                                    }
                                    if z_n > max_val {
                                        max_val = z_n;
                                    }
                                }
                            }
                            filter_min_vals.push_back(min_val);
                            filter_max_vals.push_back(max_val);
                        } else {
                            // initialize the filter_vals
                            start_col = col - midpoint_x;
                            end_col = col + midpoint_x;
                            for col2 in start_col..end_col + 1 {
                                min_val = f64::INFINITY;
                                max_val = f64::NEG_INFINITY;
                                for row2 in start_row..end_row + 1 {
                                    z_n = input_fn(row2, col2);
                                    if z_n != nodata {
                                        if z_n < min_val {
                                            min_val = z_n;
                                        }
                                        if z_n > max_val {
                                            max_val = z_n;
                                        }
                                    }
                                }
                                filter_min_vals.push_back(min_val);
                                filter_max_vals.push_back(max_val);
                            }
                        }
                        z = input_fn(row, col);
                        if z != nodata {
                            min_val = f64::INFINITY;
                            max_val = f64::NEG_INFINITY;
                            for i in 0..filter_size_x {
                                if filter_min_vals[i] < min_val {
                                    min_val = filter_min_vals[i];
                                }
                                if filter_max_vals[i] > max_val {
                                    max_val = filter_max_vals[i];
                                }
                            }
                            if min_val < f64::INFINITY && max_val > f64::NEG_INFINITY {
                                data[col as usize] = output_fn(row, col, max_val - min_val);
                            }
                        }
                    }
                    tx1.send((row, data)).unwrap();
                }
            });
        }

        for row in 0..rows {
            let data = rx.recv().expect("Error receiving data from thread.");
            output.set_row_data(data.0, data.1);
            if verbose {
                progress = (100.0_f64 * row as f64 / (rows - 1) as f64) as usize;
                if progress != old_progress {
                    println!("Progress: {}%", progress);
                    old_progress = progress;
                }
            }
        }

        let elapsed_time = get_formatted_elapsed_time(start);
        output.configs.palette = "spectrum_soft.plt".to_string();
        output.add_metadata_entry(format!(
            "Created by whitebox_tools\' {} tool",
            self.get_tool_name()
        ));
        output.add_metadata_entry(format!("Input file: {}", input_file));
        output.add_metadata_entry(format!("Filter size x: {}", filter_size_x));
        output.add_metadata_entry(format!("Filter size y: {}", filter_size_y));
        output.add_metadata_entry(format!("Elapsed Time (excluding I/O): {}", elapsed_time));

        if verbose {
            println!("Saving data...")
        };
        let _ = match output.write() {
            Ok(_) => {
                if verbose {
                    println!("Output file written")
                }
            }
            Err(e) => return Err(e),
        };
        if verbose {
            println!(
                "{}",
                &format!("Elapsed Time (excluding I/O): {}", elapsed_time)
            );
        }

        Ok(())
    }
}

fn value2i(value: f64) -> f64 {
    let r = (value as u32 & 0xFF) as f64 / 255f64;
    let g = ((value as u32 >> 8) & 0xFF) as f64 / 255f64;
    let b = ((value as u32 >> 16) & 0xFF) as f64 / 255f64;

    (r + g + b) / 3f64
}

fn value2hsi(value: f64) -> (f64, f64, f64) {
    let r = (value as u32 & 0xFF) as f64 / 255f64;
    let g = ((value as u32 >> 8) & 0xFF) as f64 / 255f64;
    let b = ((value as u32 >> 16) & 0xFF) as f64 / 255f64;

    let i = (r + g + b) / 3f64;

    let rn = r / (r + g + b);
    let gn = g / (r + g + b);
    let bn = b / (r + g + b);

    let mut h = if rn != gn || rn != bn {
        ((0.5 * ((rn - gn) + (rn - bn))) / ((rn - gn) * (rn - gn) + (rn - bn) * (gn - bn)).sqrt())
            .acos()
    } else {
        0f64
    };
    if b > g {
        h = 2f64 * PI - h;
    }

    let s = 1f64 - 3f64 * rn.min(gn).min(bn);

    (h, s, i)
}

fn hsi2value(h: f64, s: f64, i: f64) -> f64 {
    let mut r: u32;
    let mut g: u32;
    let mut b: u32;

    let x = i * (1f64 - s);

    if h < 2f64 * PI / 3f64 {
        let y = i * (1f64 + (s * h.cos()) / ((PI / 3f64 - h).cos()));
        let z = 3f64 * i - (x + y);
        r = (y * 255f64).round() as u32;
        g = (z * 255f64).round() as u32;
        b = (x * 255f64).round() as u32;
    } else if h < 4f64 * PI / 3f64 {
        let h = h - 2f64 * PI / 3f64;
        let y = i * (1f64 + (s * h.cos()) / ((PI / 3f64 - h).cos()));
        let z = 3f64 * i - (x + y);
        r = (x * 255f64).round() as u32;
        g = (y * 255f64).round() as u32;
        b = (z * 255f64).round() as u32;
    } else {
        let h = h - 4f64 * PI / 3f64;
        let y = i * (1f64 + (s * h.cos()) / ((PI / 3f64 - h).cos()));
        let z = 3f64 * i - (x + y);
        r = (z * 255f64).round() as u32;
        g = (x * 255f64).round() as u32;
        b = (y * 255f64).round() as u32;
    }

    if r > 255u32 {
        r = 255u32;
    }
    if g > 255u32 {
        g = 255u32;
    }
    if b > 255u32 {
        b = 255u32;
    }

    ((255 << 24) | (b << 16) | (g << 8) | r) as f64
}
