/*
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 whitebox_common::structures::Array2D;
use crate::tools::*;
use num_cpus;
use std::env;
use std::f64;
use std::i32;
use std::io::{Error, ErrorKind};
use std::path;
use std::sync::mpsc;
use std::sync::Arc;
use std::thread;

/// This tool performs a high-pass filter on a raster image. High-pass filters can be used to emphasize
/// the short-range variability in an image. The algorithm operates essentially by subtracting the value at
/// the grid cell at the centre of the window from the average value in the surrounding neighbourhood (i.e. window.)
///
/// 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
/// `HighPassMedianFilter`, `MeanFilter`
pub struct HighPassFilter {
    name: String,
    description: String,
    toolbox: String,
    parameters: Vec<ToolParameter>,
    example_usage: String,
}

impl HighPassFilter {
    pub fn new() -> HighPassFilter {
        // public constructor
        let name = "HighPassFilter".to_string();
        let toolbox = "Image Processing Tools/Filters".to_string();
        let description = "Performs a high-pass filter on an input image.".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);

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

impl WhiteboxTool for HighPassFilter {
    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 {
        match serde_json::to_string(&self.parameters) {
            Ok(json_str) => return format!("{{\"parameters\":{}}}", json_str),
            Err(err) => return format!("{:?}", err),
        }
    }

    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 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 min_val = if !is_rgb_image {
            input.configs.minimum
        } else {
            0f64
        };

        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
            })
        };

        // create the integral images
        let mut integral: Array2D<f64> = Array2D::new(rows, columns, 0f64, nodata)?;
        let mut integral_n: Array2D<i32> = Array2D::new(rows, columns, 0, -1)?;

        let mut val: f64;
        let mut sum: f64;
        let mut sum_n: i32;
        let mut i_prev: f64;
        let mut n_prev: i32;
        for row in 0..rows {
            sum = 0f64;
            sum_n = 0;
            for col in 0..columns {
                val = input_fn(row, col);
                if val == nodata {
                    val = 0f64;
                } else {
                    val -= min_val;
                    sum_n += 1;
                }
                sum += val;
                if row > 0 {
                    i_prev = integral[(row - 1, col)];
                    n_prev = integral_n[(row - 1, col)];
                    integral[(row, col)] = sum + i_prev;
                    integral_n[(row, col)] = sum_n + n_prev;
                } else {
                    integral[(row, col)] = sum;
                    integral_n[(row, col)] = sum_n;
                }
            }
            if verbose {
                progress = (100.0_f64 * row as f64 / (rows - 1) as f64) as usize;
                if progress != old_progress {
                    println!("Creating integral images: {}%", progress);
                    old_progress = progress;
                }
            }
        }

        let i = Arc::new(integral); // wrap integral in an Arc
        let i_n = Arc::new(integral_n); // wrap integral_n in an Arc
        let mut output = Raster::initialize_using_file(&output_file, &input);
        output.configs.data_type = DataType::F32;
        output.configs.photometric_interp = PhotometricInterpretation::Continuous;

        let (tx, rx) = mpsc::channel();
        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;
        }
        for tid in 0..num_procs {
            let input = input.clone();
            let i = i.clone();
            let i_n = i_n.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 (mut x1, mut x2, mut y1, mut y2): (isize, isize, isize, isize);
                let mut n: i32;
                let mut sum: f64;
                let mut mean: f64;
                let mut z: f64;
                for row in (0..rows).filter(|r| r % num_procs == tid) {
                    y1 = row - midpoint_y - 1;
                    if y1 < 0 {
                        y1 = 0;
                    }
                    if y1 >= rows {
                        y1 = rows - 1;
                    }

                    y2 = row + midpoint_y;
                    if y2 < 0 {
                        y2 = 0;
                    }
                    if y2 >= rows {
                        y2 = rows - 1;
                    }
                    let mut data = vec![nodata; columns as usize];
                    for col in 0..columns {
                        z = input_fn(row, col);
                        if z != nodata {
                            x1 = col - midpoint_x - 1;
                            if x1 < 0 {
                                x1 = 0;
                            }
                            if x1 >= columns {
                                x1 = columns - 1;
                            }

                            x2 = col + midpoint_x;
                            if x2 < 0 {
                                x2 = 0;
                            }
                            if x2 >= columns {
                                x2 = columns - 1;
                            }
                            n = i_n[(y2, x2)] + i_n[(y1, x1)] - i_n[(y1, x2)] - i_n[(y2, x1)];
                            if n > 0 {
                                sum = i[(y2, x2)] + i[(y1, x1)] - i[(y1, x2)] - i[(y2, x1)];
                                mean = sum / n as f64 + min_val;
                                data[col as usize] = z - mean;
                            } else {
                                data[col as usize] = 0f64;
                            }
                        }
                    }

                    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.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
}
