use cssparser::{serialize_identifier, SourceLocation};
use parcel_sourcemap::{SourceMap, OriginalLocation};
use crate::vendor_prefix::VendorPrefix;
use crate::targets::Browsers;
use crate::css_modules::CssModule;
use crate::dependencies::Dependency;
use crate::error::{PrinterError, PrinterErrorKind, Error, ErrorLocation};
use crate::rules::Location;

#[derive(Default, Debug)]
pub struct PseudoClasses<'a> {
  pub hover: Option<&'a str>,
  pub active: Option<&'a str>,
  pub focus: Option<&'a str>,
  pub focus_visible: Option<&'a str>,
  pub focus_within: Option<&'a str>
}

pub(crate) struct Printer<'a, W> {
  pub sources: Option<&'a Vec<String>>,
  dest: &'a mut W,
  source_map: Option<&'a mut SourceMap>,
  pub source_index: u32,
  indent: u8,
  line: u32,
  col: u32,
  pub minify: bool,
  pub targets: Option<Browsers>,
  /// Vendor prefix override. When non-empty, it overrides 
  /// the vendor prefix of whatever is being printed.
  pub vendor_prefix: VendorPrefix,
  pub in_calc: bool,
  pub css_module: Option<CssModule<'a>>,
  pub dependencies: Option<&'a mut Vec<Dependency>>,
  pub pseudo_classes: Option<PseudoClasses<'a>>
}

impl<'a, W: std::fmt::Write + Sized> Printer<'a, W> {
  pub fn new(
    dest: &'a mut W,
    source_map: Option<&'a mut SourceMap>,
    minify: bool,
    targets: Option<Browsers>
  ) -> Printer<'a, W> {
    Printer {
      sources: None,
      dest,
      source_map,
      source_index: 0,
      indent: 0,
      line: 0,
      col: 0,
      minify,
      targets,
      vendor_prefix: VendorPrefix::empty(),
      in_calc: false,
      css_module: None,
      dependencies: None,
      pseudo_classes: None
    }
  }

  pub fn filename(&self) -> &str {
    if let Some(sources) = self.sources {
      if let Some(f) = sources.get(self.source_index as usize) {
        f
      } else {
        "unknown.css"
      }
    } else {
      "unknown.css"
    }
  }

  pub fn write_str(&mut self, s: &str) -> Result<(), PrinterError> {
    self.col += s.len() as u32;
    self.dest.write_str(s)?;
    Ok(())
  }

  pub fn write_char(&mut self, c: char) -> Result<(), PrinterError> {
    if c == '\n' {
      self.line += 1;
      self.col = 0;
    } else {
      self.col += 1;
    }
    self.dest.write_char(c)?;
    Ok(())
  }

  pub fn whitespace(&mut self) -> Result<(), PrinterError> {
    if self.minify {
      return Ok(())
    }

    self.write_char(' ')
  }

  pub fn delim(&mut self, delim: char, ws_before: bool) -> Result<(), PrinterError> {
    if ws_before {
      self.whitespace()?;
    }
    self.write_char(delim)?;
    self.whitespace()
  }

  pub fn newline(&mut self) -> Result<(), PrinterError> {
    if self.minify {
      return Ok(())
    }

    self.write_char('\n')?;
    if self.indent > 0 {
      self.write_str(&" ".repeat(self.indent as usize))?;
    }

    Ok(())
  }

  pub fn indent(&mut self) {
    self.indent += 2;
  }

  pub fn dedent(&mut self) {
    self.indent -= 2;
  }

  pub fn indent_by(&mut self, amt: u8) {
    self.indent += amt;
  }

  pub fn dedent_by(&mut self, amt: u8) {
    self.indent -= amt;
  }

  pub fn is_nested(&self) -> bool {
    self.indent > 2
  }

  pub fn add_mapping(&mut self, loc: Location) {
    self.source_index = loc.source_index;
    if let Some(map) = &mut self.source_map {
      map.add_mapping(self.line, self.col, Some(OriginalLocation {
        original_line: loc.line,
        original_column: loc.column - 1,
        source: loc.source_index,
        name: None
      }))
    }
  }

  pub fn write_ident(&mut self, ident: &str) -> Result<(), PrinterError> {
    serialize_identifier(ident, self)?;
    let hash = if let Some(css_module) = &self.css_module {
      Some(css_module.hash)
    } else {
      None
    };

    if let Some(hash) = hash {
      self.write_char('_')?;
      self.write_str(hash)?;
      if self.source_index > 0 {
        self.write_str(&format!("_{}", self.source_index))?;
      }
    }

    if let Some(css_module) = &mut self.css_module {
      css_module.add_local(&ident, &ident);
    }

    Ok(())
  }

  pub fn error(&self, kind: PrinterErrorKind, loc: SourceLocation) -> Error<PrinterErrorKind> {
    Error {
      kind,
      loc: Some(ErrorLocation {
        filename: self.filename().into(),
        line: loc.line,
        column: loc.column
      })
    }
  }
}

impl<'a, W: std::fmt::Write + Sized> std::fmt::Write for Printer<'a, W> {
  fn write_str(&mut self, s: &str) -> std::fmt::Result {
    self.col += s.len() as u32;
    self.dest.write_str(s)
  }
}