use crate::progress::ProgressInfo;
use crate::progress::ProgressState;
use std::collections::HashMap;
use std::io::{self, Write};
use std::sync::{Arc, Mutex};

pub struct ProgressSimpleRenderer<'a> {
    /// Use sub-progress (split by "/", indent by level)
    /// If no relevant parent node exists, show parent progress as overall percentage of child progress
    pub subprogress: bool,

    /// Sorting rule
    pub sorting: RendererSortingRule,

    /// Theme
    pub theme: RendererTheme<'a>,

    /// Whether to automatically remove completed (100%) progress items
    pub auto_remove_completed: bool,

    /// Internal state storage
    states: Arc<Mutex<HashMap<String, ProgressState>>>,

    /// Number of lines rendered last time
    last_line_count: Arc<Mutex<usize>>,
}

impl<'a> ProgressSimpleRenderer<'a> {
    /// Create a new renderer
    pub fn new() -> Self {
        Self {
            subprogress: false,
            sorting: RendererSortingRule::Append,
            theme: RendererTheme::default(),
            auto_remove_completed: true,
            states: Arc::new(Mutex::new(HashMap::new())),
            last_line_count: Arc::new(Mutex::new(0)),
        }
    }

    /// Set whether to use sub-progress
    pub fn with_subprogress(mut self, subprogress: bool) -> Self {
        self.subprogress = subprogress;
        self
    }

    /// Set sorting rule
    pub fn with_sorting(mut self, sorting: RendererSortingRule) -> Self {
        self.sorting = sorting;
        self
    }

    /// Set theme
    pub fn with_theme(mut self, theme: RendererTheme<'a>) -> Self {
        self.theme = theme;
        self
    }

    /// Set whether to automatically remove completed (100%) progress items
    pub fn with_auto_remove_completed(mut self, auto_remove: bool) -> Self {
        self.auto_remove_completed = auto_remove;
        self
    }

    /// Update progress state and render
    pub fn update(&self, name: String, state: ProgressState) {
        {
            let mut states = self.states.lock().unwrap();

            if self.auto_remove_completed && state.progress() >= 1.0 {
                states.remove(&name);
            } else {
                states.insert(name.clone(), state);
            }
        }

        // Render all states
        self.render_all();
    }

    /// Clear the previously rendered content in the terminal
    fn clear_previous_output(&self) {
        let line_count = *self.last_line_count.lock().unwrap();
        if line_count > 0 {
            print!("\x1B[{}A\x1B[0J", line_count);
        }
    }

    /// Save the number of lines rendered this time
    fn save_line_count(&self, count: usize) {
        let mut last_line_count = self.last_line_count.lock().unwrap();
        *last_line_count = count;
    }

    /// Render all progress states
    pub fn render_all(&self) {
        let states = self.states.lock().unwrap();

        if states.is_empty() {
            self.clear_previous_output();
            self.save_line_count(0);
            return;
        }

        // Collect all progress items
        let mut items: Vec<ProgressItem> = Vec::new();

        for (name, state) in states.iter() {
            // If `auto_remove_completed` is enabled, skip 100% progress items
            if self.auto_remove_completed && state.progress() >= 1.0 {
                continue;
            }

            items.push(ProgressItem {
                name: name.clone(),
                progress: state.progress(),
                info: state.info(),
                depth: 0,
                is_parent: false,
            });
        }

        // If `subprogress` is enabled, compute hierarchy
        if self.subprogress {
            self.process_subprogress(&mut items);
        }

        // Sort
        self.sort_items(&mut items);

        // Render and save line count
        let line_count = self.render_items(&items);
        self.save_line_count(line_count);
    }

    /// Clear all progress states
    pub fn clear(&self) {
        // Clear previous output
        self.clear_previous_output();

        let mut states = self.states.lock().unwrap();
        states.clear();

        // Reset line count
        self.save_line_count(0);
    }

    /// Process sub-progress, compute levels and indentation
    fn process_subprogress(&self, items: &mut Vec<ProgressItem>) {
        // Find parent nodes
        let mut parent_items: Vec<String> = Vec::new();

        for item in items.iter() {
            let parts: Vec<&str> = item.name.split('/').collect();
            if parts.len() > 1 {
                // Build parent node path
                for i in 1..parts.len() {
                    let parent_path = parts[0..i].join("/");
                    if !parent_items.contains(&parent_path) {
                        parent_items.push(parent_path);
                    }
                }
            }
        }

        // Compute depth for each item
        for item in items.iter_mut() {
            item.depth = item.name.matches('/').count();
        }

        // Add missing parent nodes
        for parent_path in parent_items {
            if !items.iter().any(|item| item.name == parent_path) {
                // Compute parent node progress
                let child_progress: Vec<f32> = items
                    .iter()
                    .filter(|item| item.name.starts_with(&format!("{}/", parent_path)))
                    .map(|item| item.progress)
                    .collect();

                let avg_progress = if !child_progress.is_empty() {
                    child_progress.iter().sum::<f32>() / child_progress.len() as f32
                } else {
                    0.0
                };

                items.push(ProgressItem {
                    name: parent_path.clone(),
                    progress: avg_progress,
                    info: ProgressInfo::Empty,
                    depth: parent_path.matches('/').count(),
                    is_parent: true,
                });
            }
        }

        // Mark parent nodes
        let item_names: Vec<String> = items.iter().map(|item| item.name.clone()).collect();
        for item in items.iter_mut() {
            if item_names.iter().any(|other_name| {
                other_name != &item.name && other_name.starts_with(&format!("{}/", item.name))
            }) {
                item.is_parent = true;
            }
        }
    }

    /// Sort items according to sorting rule
    fn sort_items(&self, items: &mut Vec<ProgressItem>) {
        if self.subprogress {
            items.sort_by(|a, b| match self.sorting {
                RendererSortingRule::Append => a.name.cmp(&b.name),
                RendererSortingRule::AlphabeticalAsc => a.name.cmp(&b.name),
                RendererSortingRule::AlphabeticalDesc => b.name.cmp(&a.name),
            });
        } else {
            match self.sorting {
                RendererSortingRule::AlphabeticalAsc => {
                    items.sort_by(|a, b| a.name.cmp(&b.name));
                }
                RendererSortingRule::AlphabeticalDesc => {
                    items.sort_by(|a, b| b.name.cmp(&a.name));
                }
                RendererSortingRule::Append => {}
            }
        }
    }

    /// Render all items, return the number of lines rendered
    fn render_items(&self, items: &[ProgressItem]) -> usize {
        // Compute maximum width for alignment
        let max_name_width = items
            .iter()
            .map(|item| {
                let indent = if self.subprogress {
                    item.depth * self.theme.indent_spaces
                } else {
                    0
                };
                let display_name_len = if self.subprogress {
                    // For sub-progress, only show the last part
                    item.name.split('/').last().unwrap_or(&item.name).len()
                } else {
                    item.name.len()
                };
                display_name_len + indent
            })
            .max()
            .unwrap_or(0);

        let max_state_width = if self.theme.show_state {
            items
                .iter()
                .map(|item| self.format_state(item.info).len())
                .max()
                .unwrap_or(0)
        } else {
            0
        };

        // Build complete output string
        let mut output = String::new();

        // Add clear command
        let line_count = *self.last_line_count.lock().unwrap();
        if line_count > 0 {
            output.push_str(&format!("\x1B[{}A\x1B[0J", line_count));
        }

        // Add all lines
        for item in items {
            let line = self.format_item(item, max_name_width, max_state_width);
            output.push_str(&line);
            output.push('\n');
        }

        // Disable buffering, output immediately
        let _ = io::stdout().write_all(output.as_bytes());
        let _ = io::stdout().flush();

        items.len()
    }

    /// Format a single item
    fn format_item(
        &self,
        item: &ProgressItem,
        max_name_width: usize,
        max_state_width: usize,
    ) -> String {
        let mut result = String::new();
        let layout = self.theme.layout;

        // Parse layout template
        for part in layout.split(',') {
            match part.trim() {
                "{name}" => {
                    let name = self.format_name(item, max_name_width);
                    result.push_str(&name);
                }
                "{state}" => {
                    if self.theme.show_state {
                        let state = self.format_state(item.info);
                        if !state.is_empty() {
                            let state = if self.theme.align {
                                self.align_component(&state, max_state_width, false)
                            } else {
                                state
                            };
                            result.push_str(&state);
                        }
                    }
                }
                "{progress}" => {
                    if self.theme.show_progress {
                        let progress = self.format_progress(item.progress);
                        if !progress.is_empty() {
                            let progress = if self.theme.align {
                                self.align_component(&progress, 0, false)
                            } else {
                                progress
                            };
                            result.push_str(&progress);
                        }
                    }
                }
                "{percent}" => {
                    if self.theme.show_percent {
                        let percent = self.format_percent(item.progress);
                        if !percent.is_empty() {
                            let percent = if self.theme.align {
                                self.align_component(&percent, 0, false)
                            } else {
                                percent
                            };
                            result.push_str(&percent);
                        }
                    }
                }
                _ => {
                    // Output as-is
                    result.push_str(part);
                }
            }
        }

        result
    }

    /// Format name (including indentation)
    fn format_name(&self, item: &ProgressItem, max_width: usize) -> String {
        let indent = if self.subprogress {
            " ".repeat(item.depth * self.theme.indent_spaces)
        } else {
            String::new()
        };

        // Only show the last part of the path
        let display_name = if self.subprogress {
            item.name
                .split('/')
                .last()
                .unwrap_or(&item.name)
                .to_string()
        } else {
            item.name.clone()
        };

        let name = format!("{}{}", indent, display_name);

        if self.theme.align {
            self.align_component(&name, max_width, true)
        } else {
            name
        }
    }

    /// Format state
    fn format_state(&self, info: ProgressInfo) -> String {
        match info {
            ProgressInfo::Empty => self.theme.state_empty.to_string(),
            ProgressInfo::Info(msg) => self.theme.state_info.replace("{}", msg),
            ProgressInfo::Warning(msg) => self.theme.state_warning.replace("{}", msg),
            ProgressInfo::Error(msg) => self.theme.state_error.replace("{}", msg),
        }
    }

    /// Format progress bar
    fn format_progress(&self, progress: f32) -> String {
        let filled_len = (progress * self.theme.progress_content_len as f32).round() as usize;
        let empty_len = self.theme.progress_content_len - filled_len;

        let filled = self.theme.progress_filled_char.repeat(filled_len);
        let empty = self.theme.progress_empty_char.repeat(empty_len);

        self.theme
            .progress
            .replace("{}", &format!("{}{}", filled, empty))
    }

    /// Format percentage
    fn format_percent(&self, progress: f32) -> String {
        let percent = progress * 100.0;
        let formatted = format!("{:.1$}", percent, self.theme.percent_decimal_places);
        self.theme.percent.replace("{}", &formatted)
    }

    /// Align component
    fn align_component(
        &self,
        component: &str,
        max_width: usize,
        is_first_component: bool,
    ) -> String {
        let trimmed = if is_first_component {
            // For the first component, only trim the end, not the beginning
            component.trim_end()
        } else {
            component.trim()
        };

        if trimmed.is_empty() {
            // Empty component is not aligned, return empty string
            String::new()
        } else {
            let padding = max_width.saturating_sub(trimmed.len());
            let before_padding = " ".repeat(self.theme.align_padding_before);
            let after_padding = " ".repeat(self.theme.align_padding_after);
            format!(
                "{}{}{}{}",
                before_padding,
                trimmed,
                " ".repeat(padding),
                after_padding
            )
        }
    }
}

struct ProgressItem {
    name: String,
    progress: f32,
    info: ProgressInfo,
    depth: usize,
    is_parent: bool,
}

pub enum RendererSortingRule {
    /// Append, newly added progress items are always at the end
    Append,

    /// Sort by name in ascending alphabetical order
    AlphabeticalAsc,

    /// Sort by name in descending alphabetical order
    AlphabeticalDesc,
}

pub struct RendererTheme<'a> {
    /// Alignment
    /// When enabled, ensures the first character of each component of each item is aligned
    /// At the same time, each component will be trimmed before and after
    pub align: bool,

    /// Number of spaces before a component when aligning
    pub align_padding_before: usize,

    /// Number of spaces after a component when aligning
    pub align_padding_after: usize,

    /// Overall layout
    pub layout: &'a str,

    /// Show state (different from setting in `layout`, it affects whether this component is rendered)
    pub show_state: bool,

    /// Warning state style
    pub state_warning: &'a str,

    /// Error state style
    pub state_error: &'a str,

    /// Info state style
    pub state_info: &'a str,

    /// Empty state style
    pub state_empty: &'a str,

    /// Show progress bar (different from setting in `layout`, it affects whether this component is rendered)
    pub show_progress: bool,

    /// Progress bar style
    pub progress: &'a str,

    /// Number of content characters in the progress bar
    pub progress_content_len: usize,

    /// Character for filled part
    pub progress_filled_char: &'a str,

    /// Character for unfilled part
    pub progress_empty_char: &'a str,

    /// Show percentage (different from setting in `layout`, it affects whether this component is rendered)
    pub show_percent: bool,

    /// Percentage style
    pub percent: &'a str,

    /// Number of decimal places for percentage
    pub percent_decimal_places: usize,

    /// Number of spaces per indentation level
    pub indent_spaces: usize,
}

impl<'a> Default for RendererTheme<'a> {
    fn default() -> Self {
        Self {
            align: true,
            layout: "{name},{state},{progress},{percent}",
            show_state: true,
            state_warning: "  WARN: {}",
            state_error: "   ERR: {}",
            state_info: "  INFO: {}",
            state_empty: "",
            show_progress: true,
            progress: "  [{}]",
            progress_content_len: 20,
            progress_filled_char: "#",
            progress_empty_char: " ",
            show_percent: true,
            percent: "  ({}%)",
            percent_decimal_places: 1,
            indent_spaces: 2,
            align_padding_before: 0,
            align_padding_after: 1,
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::progress::{ProgressInfo, ProgressState};

    #[test]
    fn test_renderer_update() {
        let renderer = ProgressSimpleRenderer::new();

        // Test update and rendering
        renderer.update(
            "task1".to_string(),
            ProgressState {
                progress: 0.5,
                info: ProgressInfo::Info("Processing"),
            },
        );

        renderer.update(
            "task2".to_string(),
            ProgressState {
                progress: 0.75,
                info: ProgressInfo::Warning("Almost done"),
            },
        );

        // Call render_all to render
        renderer.render_all();
    }

    #[test]
    fn test_renderer_with_subprogress() {
        let renderer = ProgressSimpleRenderer::new().with_subprogress(true);

        renderer.update(
            "download/file1".to_string(),
            ProgressState {
                progress: 0.5,
                info: ProgressInfo::Info("Downloading file1"),
            },
        );

        renderer.update(
            "download/file2".to_string(),
            ProgressState {
                progress: 0.75,
                info: ProgressInfo::Info("Downloading file2"),
            },
        );

        renderer.render_all();
    }

    #[test]
    fn test_auto_remove_completed() {
        let renderer = ProgressSimpleRenderer::new().with_auto_remove_completed(true);

        // Add an unfinished task
        renderer.update(
            "task1".to_string(),
            ProgressState {
                progress: 0.5,
                info: ProgressInfo::Info("Processing"),
            },
        );

        // Add a completed task
        renderer.update(
            "task2".to_string(),
            ProgressState {
                progress: 1.0,
                info: ProgressInfo::Info("Completed"),
            },
        );

        // Render, should only show task1
        renderer.render_all();

        // Check internal state, task2 should be removed
        {
            let states = renderer.states.lock().unwrap();
            assert!(states.contains_key("task1"));
            assert!(!states.contains_key("task2"));
        }
    }

    #[test]
    fn test_auto_remove_completed_disabled() {
        let renderer = ProgressSimpleRenderer::new().with_auto_remove_completed(false);

        // Add a completed task
        renderer.update(
            "task1".to_string(),
            ProgressState {
                progress: 1.0,
                info: ProgressInfo::Info("Completed"),
            },
        );

        // Check internal state, task1 should still exist
        {
            let states = renderer.states.lock().unwrap();
            assert!(states.contains_key("task1"));
        }
    }
    #[test]
    fn test_indent_spaces_config() {
        // Create custom theme, set indent spaces to 4
        let mut theme = RendererTheme::default();
        theme.indent_spaces = 4;

        let renderer = ProgressSimpleRenderer::new()
            .with_subprogress(true)
            .with_theme(theme);

        // Add multi-level progress
        renderer.update(
            "parent".to_string(),
            ProgressState {
                progress: 0.5,
                info: ProgressInfo::Info("Parent task"),
            },
        );

        renderer.update(
            "parent/child".to_string(),
            ProgressState {
                progress: 0.75,
                info: ProgressInfo::Info("Child task"),
            },
        );

        renderer.update(
            "parent/child/grandchild".to_string(),
            ProgressState {
                progress: 0.9,
                info: ProgressInfo::Info("Grandchild task"),
            },
        );

        // Render and check
        renderer.render_all();

        // Check internal state
        {
            let states = renderer.states.lock().unwrap();
            assert!(states.contains_key("parent"));
            assert!(states.contains_key("parent/child"));
            assert!(states.contains_key("parent/child/grandchild"));
        }
    }

    #[test]
    fn test_align_padding_config() {
        // Create custom theme, set alignment padding before and after
        let mut theme = RendererTheme::default();
        theme.align = true;
        theme.align_padding_before = 2;
        theme.align_padding_after = 3;

        let renderer = ProgressSimpleRenderer::new().with_theme(theme);

        // Add test data
        renderer.update(
            "task1".to_string(),
            ProgressState {
                progress: 0.5,
                info: ProgressInfo::Info("Processing"),
            },
        );

        renderer.update(
            "task2".to_string(),
            ProgressState {
                progress: 0.75,
                info: ProgressInfo::Warning("Almost done"),
            },
        );

        // Render and check
        renderer.render_all();

        // Check internal state
        {
            let states = renderer.states.lock().unwrap();
            assert!(states.contains_key("task1"));
            assert!(states.contains_key("task2"));
        }
    }

    #[test]
    fn test_align_padding_with_empty_state() {
        // Create custom theme, set alignment padding before and after
        let mut theme = RendererTheme::default();
        theme.align = true;
        theme.align_padding_before = 1;
        theme.align_padding_after = 2;
        theme.show_state = true;

        let renderer = ProgressSimpleRenderer::new().with_theme(theme);

        // Add test data - empty state
        renderer.update(
            "task1".to_string(),
            ProgressState {
                progress: 0.5,
                info: ProgressInfo::Empty,
            },
        );

        // Add test data - with state
        renderer.update(
            "task2".to_string(),
            ProgressState {
                progress: 0.75,
                info: ProgressInfo::Info("Processing"),
            },
        );

        // Render and check
        renderer.render_all();

        // Check internal state
        {
            let states = renderer.states.lock().unwrap();
            assert!(states.contains_key("task1"));
            assert!(states.contains_key("task2"));
        }
    }

    #[test]
    fn test_align_first_component_no_trim_start() {
        let renderer = ProgressSimpleRenderer::new();

        // Test that the first component does not trim the start when aligning
        let component = "  test  ";
        let aligned = renderer.align_component(component, 10, true);

        // The first component should only trim the end, not the start
        assert!(aligned.starts_with("  test"));
        assert!(!aligned.starts_with("test"));
    }

    #[test]
    fn test_align_non_first_component_trim_both() {
        let renderer = ProgressSimpleRenderer::new();

        // Test that non-first components trim both sides when aligning
        let component = "  test  ";
        let aligned = renderer.align_component(component, 10, false);

        // Non-first components should trim both sides
        assert!(aligned.starts_with("test"));
        assert!(!aligned.starts_with("  test"));
    }

    #[test]
    fn test_format_progress() {
        let renderer = ProgressSimpleRenderer::new();
        let progress = renderer.format_progress(0.5);
        assert!(progress.contains("["));
        assert!(progress.contains("]"));
    }

    #[test]
    fn test_format_percent() {
        let renderer = ProgressSimpleRenderer::new();
        let percent = renderer.format_percent(0.5);
        assert!(percent.contains("50"));
        assert!(percent.contains("%"));
    }

    #[test]
    fn test_subprogress_indentation() {
        let renderer = ProgressSimpleRenderer::new().with_subprogress(true);

        // Add parent and child nodes
        renderer.update(
            "progress".to_string(),
            ProgressState {
                progress: 0.95,
                info: ProgressInfo::Info("Processing"),
            },
        );

        renderer.update(
            "progress/2".to_string(),
            ProgressState {
                progress: 0.95,
                info: ProgressInfo::Info("Step 2"),
            },
        );

        renderer.update(
            "progress/3".to_string(),
            ProgressState {
                progress: 0.8,
                info: ProgressInfo::Info("Step 3"),
            },
        );

        // Render and check output format
        renderer.render_all();

        // Check internal state
        {
            let states = renderer.states.lock().unwrap();
            assert!(states.contains_key("progress"));
            assert!(states.contains_key("progress/2"));
            assert!(states.contains_key("progress/3"));
        }
    }
}