use std::fmt;

use atty::Stream;

use crate::protocol::Diagnostic;
use crate::GraphicalReportHandler;
use crate::GraphicalTheme;
use crate::NarratableReportHandler;
use crate::ReportHandler;
use crate::ThemeCharacters;
use crate::ThemeStyles;

/**
Create a custom [MietteHandler] from options.

## Example

```no_run
miette::set_hook(Box::new(|_| {
    Box::new(miette::MietteHandlerOpts::new()
        .terminal_links(true)
        .unicode(false)
        .context_lines(3)
        .build())
}))
# .unwrap();
```
*/
#[derive(Default, Debug, Clone)]
pub struct MietteHandlerOpts {
    pub(crate) linkify: Option<bool>,
    pub(crate) width: Option<usize>,
    pub(crate) theme: Option<GraphicalTheme>,
    pub(crate) force_graphical: Option<bool>,
    pub(crate) force_narrated: Option<bool>,
    pub(crate) ansi_colors: Option<bool>,
    pub(crate) rgb_colors: Option<bool>,
    pub(crate) color: Option<bool>,
    pub(crate) unicode: Option<bool>,
    pub(crate) footer: Option<String>,
    pub(crate) context_lines: Option<usize>,
    pub(crate) tab_width: Option<usize>,
}

impl MietteHandlerOpts {
    /// Create a new [MietteHandlerOpts].
    pub fn new() -> Self {
        Default::default()
    }

    /// If true, specify whether the graphical handler will make codes be
    /// clickable links in supported terminals. Defaults to auto-detection
    /// based on known supported terminals.
    pub fn terminal_links(mut self, linkify: bool) -> Self {
        self.linkify = Some(linkify);
        self
    }

    /// Set a graphical theme for the handler when rendering in graphical
    /// mode. Use [MietteHandlerOpts::force_graphical] to force graphical
    /// mode. This option overrides [MietteHandlerOpts::color].
    pub fn graphical_theme(mut self, theme: GraphicalTheme) -> Self {
        self.theme = Some(theme);
        self
    }

    /// Sets the width to wrap the report at. Defaults
    pub fn width(mut self, width: usize) -> Self {
        self.width = Some(width);
        self
    }

    /// If true, colors will be used during graphical rendering. Actual color
    /// format will be auto-detected.
    pub fn color(mut self, color: bool) -> Self {
        self.color = Some(color);
        self
    }

    /// If true, RGB colors will be used during graphical rendering.
    pub fn rgb_colors(mut self, color: bool) -> Self {
        self.rgb_colors = Some(color);
        self
    }

    /// If true, forces unicode display for graphical output. If set to false,
    /// forces ASCII art display.
    pub fn unicode(mut self, unicode: bool) -> Self {
        self.unicode = Some(unicode);
        self
    }

    /// If true, ANSI colors will be used during graphical rendering.
    pub fn ansi_colors(mut self, color: bool) -> Self {
        self.rgb_colors = Some(color);
        self
    }
    /// If true, graphical rendering will be used regardless of terminal
    /// detection.
    pub fn force_graphical(mut self, force: bool) -> Self {
        self.force_graphical = Some(force);
        self
    }

    /// If true, forces use of the narrated renderer.
    pub fn force_narrated(mut self, force: bool) -> Self {
        self.force_narrated = Some(force);
        self
    }

    /// Set a footer to be displayed at the bottom of the report.
    pub fn footer(mut self, footer: String) -> Self {
        self.footer = Some(footer);
        self
    }

    /// Sets the number of context lines before and after a span to display.
    pub fn context_lines(mut self, context_lines: usize) -> Self {
        self.context_lines = Some(context_lines);
        self
    }

    /// Set the displayed tab width in spaces.
    pub fn tab_width(mut self, width: usize) -> Self {
        self.tab_width = Some(width);
        self
    }

    /// Builds a [MietteHandler] from this builder.
    pub fn build(self) -> MietteHandler {
        let graphical = self.is_graphical();
        let width = self.get_width();
        if !graphical {
            let mut handler = NarratableReportHandler::new();
            if let Some(footer) = self.footer {
                handler = handler.with_footer(footer);
            }
            if let Some(context_lines) = self.context_lines {
                handler = handler.with_context_lines(context_lines);
            }
            MietteHandler {
                inner: Box::new(handler),
            }
        } else {
            let linkify = self.use_links();
            let characters = match self.unicode {
                Some(true) => ThemeCharacters::unicode(),
                Some(false) => ThemeCharacters::ascii(),
                None if supports_unicode::on(Stream::Stderr) => ThemeCharacters::unicode(),
                None => ThemeCharacters::ascii(),
            };
            let styles = if self.rgb_colors == Some(true) {
                ThemeStyles::rgb()
            } else if self.ansi_colors == Some(true) {
                ThemeStyles::ansi()
            } else if let Some(colors) = supports_color::on(Stream::Stderr) {
                if colors.has_16m {
                    ThemeStyles::rgb()
                } else {
                    ThemeStyles::ansi()
                }
            } else if self.color == Some(true) {
                ThemeStyles::ansi()
            } else {
                ThemeStyles::none()
            };
            let mut handler = GraphicalReportHandler::new()
                .with_width(width)
                .with_links(linkify)
                .with_theme(GraphicalTheme { characters, styles });
            if let Some(footer) = self.footer {
                handler = handler.with_footer(footer);
            }
            if let Some(context_lines) = self.context_lines {
                handler = handler.with_context_lines(context_lines);
            }
            if let Some(w) = self.tab_width {
                handler = handler.tab_width(w);
            }
            MietteHandler {
                inner: Box::new(handler),
            }
        }
    }

    pub(crate) fn is_graphical(&self) -> bool {
        if let Some(force_narrated) = self.force_narrated {
            !force_narrated
        } else if let Some(force_graphical) = self.force_graphical {
            force_graphical
        } else if let Some(info) = supports_color::on(Stream::Stderr) {
            info.has_basic
        } else {
            false
        }
    }

    // Detects known terminal apps based on env variables and returns true if
    // they support rendering links.
    pub(crate) fn use_links(&self) -> bool {
        if let Some(linkify) = self.linkify {
            linkify
        } else {
            supports_hyperlinks::on(Stream::Stderr)
        }
    }

    pub(crate) fn get_width(&self) -> usize {
        self.width
            .unwrap_or_else(|| term_size::dimensions().unwrap_or((80, 0)).0)
    }
}

/**
A [ReportHandler] that displays a given [crate::Report] in a quasi-graphical
way, using terminal colors, unicode drawing characters, and other such things.

This is the default reporter bundled with `miette`.

This printer can be customized by using `new_themed()` and handing it a
[GraphicalTheme] of your own creation (or using one of its own defaults!)

See [crate::set_hook] for more details on customizing your global printer.
*/
#[allow(missing_debug_implementations)]
pub struct MietteHandler {
    inner: Box<dyn ReportHandler + Send + Sync>,
}

impl MietteHandler {
    /// Creates a new [MietteHandler] with default settings.
    pub fn new() -> Self {
        Default::default()
    }
}

impl Default for MietteHandler {
    fn default() -> Self {
        MietteHandlerOpts::new().build()
    }
}

impl ReportHandler for MietteHandler {
    fn debug(&self, diagnostic: &(dyn Diagnostic), f: &mut fmt::Formatter<'_>) -> fmt::Result {
        if f.alternate() {
            return fmt::Debug::fmt(diagnostic, f);
        }

        self.inner.debug(diagnostic, f)
    }
}