mod keymap_file;
pub mod settings_file;
pub mod watched_json;

use anyhow::Result;
use gpui::{
    font_cache::{FamilyId, FontCache},
    AssetSource,
};
use schemars::{
    gen::{SchemaGenerator, SchemaSettings},
    schema::{InstanceType, ObjectValidation, Schema, SchemaObject, SingleOrVec},
    JsonSchema,
};
use serde::{de::DeserializeOwned, Deserialize, Serialize};
use serde_json::Value;
use std::{collections::HashMap, fmt::Write as _, num::NonZeroU32, str, sync::Arc};
use theme::{Theme, ThemeRegistry};
use tree_sitter::Query;
use util::ResultExt as _;

pub use keymap_file::{keymap_file_json_schema, KeymapFileContent};

#[derive(Clone)]
pub struct Settings {
    pub experiments: FeatureFlags,
    pub projects_online_by_default: bool,
    pub buffer_font_family: FamilyId,
    pub default_buffer_font_size: f32,
    pub buffer_font_size: f32,
    pub hover_popover_enabled: bool,
    pub show_completions_on_input: bool,
    pub vim_mode: bool,
    pub autosave: Autosave,
    pub default_dock_anchor: DockAnchor,
    pub editor_defaults: EditorSettings,
    pub editor_overrides: EditorSettings,
    pub git: GitSettings,
    pub git_overrides: GitSettings,
    pub journal_defaults: JournalSettings,
    pub journal_overrides: JournalSettings,
    pub terminal_defaults: TerminalSettings,
    pub terminal_overrides: TerminalSettings,
    pub language_defaults: HashMap<Arc<str>, EditorSettings>,
    pub language_overrides: HashMap<Arc<str>, EditorSettings>,
    pub lsp: HashMap<Arc<str>, LspSettings>,
    pub theme: Arc<Theme>,
    pub staff_mode: bool,
}

#[derive(Copy, Clone, Debug, Default, Serialize, Deserialize, JsonSchema)]
pub struct FeatureFlags {
    pub experimental_themes: bool,
}

impl FeatureFlags {
    pub fn keymap_files(&self) -> Vec<&'static str> {
        vec![]
    }
}

#[derive(Copy, Clone, Debug, Default, Serialize, Deserialize, JsonSchema)]
pub struct GitSettings {
    pub git_gutter: Option<GitGutter>,
    pub gutter_debounce: Option<u64>,
}

#[derive(Clone, Copy, Debug, Default, Serialize, Deserialize, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum GitGutter {
    #[default]
    TrackedFiles,
    Hide,
}

pub struct GitGutterConfig {}

#[derive(Clone, Debug, Default, Serialize, Deserialize, JsonSchema)]
pub struct EditorSettings {
    pub tab_size: Option<NonZeroU32>,
    pub hard_tabs: Option<bool>,
    pub soft_wrap: Option<SoftWrap>,
    pub preferred_line_length: Option<u32>,
    pub format_on_save: Option<FormatOnSave>,
    pub formatter: Option<Formatter>,
    pub enable_language_server: Option<bool>,
}

#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum SoftWrap {
    None,
    EditorWidth,
    PreferredLineLength,
}
#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum FormatOnSave {
    On,
    Off,
    LanguageServer,
    External {
        command: String,
        arguments: Vec<String>,
    },
}

#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum Formatter {
    LanguageServer,
    External {
        command: String,
        arguments: Vec<String>,
    },
}

#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum Autosave {
    Off,
    AfterDelay { milliseconds: u64 },
    OnFocusChange,
    OnWindowChange,
}

#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema)]
pub struct JournalSettings {
    pub path: Option<String>,
    pub hour_format: Option<HourFormat>,
}

impl Default for JournalSettings {
    fn default() -> Self {
        Self {
            path: Some("~".into()),
            hour_format: Some(Default::default()),
        }
    }
}

#[derive(Clone, Debug, Deserialize, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum HourFormat {
    Hour12,
    Hour24,
}

impl Default for HourFormat {
    fn default() -> Self {
        Self::Hour12
    }
}

#[derive(Clone, Debug, Default, Serialize, Deserialize, JsonSchema)]
pub struct TerminalSettings {
    pub shell: Option<Shell>,
    pub working_directory: Option<WorkingDirectory>,
    pub font_size: Option<f32>,
    pub font_family: Option<String>,
    pub env: Option<HashMap<String, String>>,
    pub blinking: Option<TerminalBlink>,
    pub alternate_scroll: Option<AlternateScroll>,
    pub option_as_meta: Option<bool>,
    pub copy_on_select: Option<bool>,
}

#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum TerminalBlink {
    Off,
    TerminalControlled,
    On,
}

impl Default for TerminalBlink {
    fn default() -> Self {
        TerminalBlink::TerminalControlled
    }
}

#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum Shell {
    System,
    Program(String),
    WithArguments { program: String, args: Vec<String> },
}

impl Default for Shell {
    fn default() -> Self {
        Shell::System
    }
}

#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum AlternateScroll {
    On,
    Off,
}

impl Default for AlternateScroll {
    fn default() -> Self {
        AlternateScroll::On
    }
}

#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum WorkingDirectory {
    CurrentProjectDirectory,
    FirstProjectDirectory,
    AlwaysHome,
    Always { directory: String },
}

#[derive(PartialEq, Eq, Debug, Default, Copy, Clone, Hash, Serialize, Deserialize, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum DockAnchor {
    #[default]
    Bottom,
    Right,
    Expanded,
}

#[derive(Clone, Debug, Default, Serialize, Deserialize, JsonSchema)]
pub struct SettingsFileContent {
    pub experiments: Option<FeatureFlags>,
    #[serde(default)]
    pub projects_online_by_default: Option<bool>,
    #[serde(default)]
    pub buffer_font_family: Option<String>,
    #[serde(default)]
    pub buffer_font_size: Option<f32>,
    #[serde(default)]
    pub hover_popover_enabled: Option<bool>,
    #[serde(default)]
    pub show_completions_on_input: Option<bool>,
    #[serde(default)]
    pub vim_mode: Option<bool>,
    #[serde(default)]
    pub autosave: Option<Autosave>,
    #[serde(default)]
    pub default_dock_anchor: Option<DockAnchor>,
    #[serde(flatten)]
    pub editor: EditorSettings,
    #[serde(default)]
    pub journal: JournalSettings,
    #[serde(default)]
    pub terminal: TerminalSettings,
    #[serde(default)]
    pub git: Option<GitSettings>,
    #[serde(default)]
    #[serde(alias = "language_overrides")]
    pub languages: HashMap<Arc<str>, EditorSettings>,
    #[serde(default)]
    pub lsp: HashMap<Arc<str>, LspSettings>,
    #[serde(default)]
    pub theme: Option<String>,
    #[serde(default)]
    pub staff_mode: Option<bool>,
}

#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub struct LspSettings {
    pub initialization_options: Option<Value>,
}

impl Settings {
    pub fn defaults(
        assets: impl AssetSource,
        font_cache: &FontCache,
        themes: &ThemeRegistry,
    ) -> Self {
        #[track_caller]
        fn required<T>(value: Option<T>) -> Option<T> {
            assert!(value.is_some(), "missing default setting value");
            value
        }

        let defaults: SettingsFileContent = parse_json_with_comments(
            str::from_utf8(assets.load("settings/default.json").unwrap().as_ref()).unwrap(),
        )
        .unwrap();

        Self {
            experiments: FeatureFlags::default(),
            buffer_font_family: font_cache
                .load_family(&[defaults.buffer_font_family.as_ref().unwrap()])
                .unwrap(),
            buffer_font_size: defaults.buffer_font_size.unwrap(),
            default_buffer_font_size: defaults.buffer_font_size.unwrap(),
            hover_popover_enabled: defaults.hover_popover_enabled.unwrap(),
            show_completions_on_input: defaults.show_completions_on_input.unwrap(),
            projects_online_by_default: defaults.projects_online_by_default.unwrap(),
            vim_mode: defaults.vim_mode.unwrap(),
            autosave: defaults.autosave.unwrap(),
            default_dock_anchor: defaults.default_dock_anchor.unwrap(),
            editor_defaults: EditorSettings {
                tab_size: required(defaults.editor.tab_size),
                hard_tabs: required(defaults.editor.hard_tabs),
                soft_wrap: required(defaults.editor.soft_wrap),
                preferred_line_length: required(defaults.editor.preferred_line_length),
                format_on_save: required(defaults.editor.format_on_save),
                formatter: required(defaults.editor.formatter),
                enable_language_server: required(defaults.editor.enable_language_server),
            },
            editor_overrides: Default::default(),
            git: defaults.git.unwrap(),
            git_overrides: Default::default(),
            journal_defaults: defaults.journal,
            journal_overrides: Default::default(),
            terminal_defaults: defaults.terminal,
            terminal_overrides: Default::default(),
            language_defaults: defaults.languages,
            language_overrides: Default::default(),
            lsp: defaults.lsp.clone(),
            theme: themes.get(&defaults.theme.unwrap()).unwrap(),

            staff_mode: false,
        }
    }

    pub fn set_user_settings(
        &mut self,
        data: SettingsFileContent,
        theme_registry: &ThemeRegistry,
        font_cache: &FontCache,
    ) {
        if let Some(value) = &data.buffer_font_family {
            if let Some(id) = font_cache.load_family(&[value]).log_err() {
                self.buffer_font_family = id;
            }
        }
        if let Some(value) = &data.theme {
            if let Some(theme) = theme_registry.get(value).log_err() {
                self.theme = theme;
            }
        }

        merge(
            &mut self.projects_online_by_default,
            data.projects_online_by_default,
        );
        merge(&mut self.buffer_font_size, data.buffer_font_size);
        merge(&mut self.default_buffer_font_size, data.buffer_font_size);
        merge(&mut self.hover_popover_enabled, data.hover_popover_enabled);
        merge(
            &mut self.show_completions_on_input,
            data.show_completions_on_input,
        );
        merge(&mut self.vim_mode, data.vim_mode);
        merge(&mut self.autosave, data.autosave);
        merge(&mut self.experiments, data.experiments);
        merge(&mut self.staff_mode, data.staff_mode);
        merge(&mut self.default_dock_anchor, data.default_dock_anchor);

        // Ensure terminal font is loaded, so we can request it in terminal_element layout
        if let Some(terminal_font) = &data.terminal.font_family {
            font_cache.load_family(&[terminal_font]).log_err();
        }

        self.editor_overrides = data.editor;
        self.git_overrides = data.git.unwrap_or_default();
        self.journal_overrides = data.journal;
        self.terminal_defaults.font_size = data.terminal.font_size;
        self.terminal_overrides.copy_on_select = data.terminal.copy_on_select;
        self.terminal_overrides = data.terminal;
        self.language_overrides = data.languages;
        self.lsp = data.lsp;
    }

    pub fn with_language_defaults(
        mut self,
        language_name: impl Into<Arc<str>>,
        overrides: EditorSettings,
    ) -> Self {
        self.language_defaults
            .insert(language_name.into(), overrides);
        self
    }

    pub fn tab_size(&self, language: Option<&str>) -> NonZeroU32 {
        self.language_setting(language, |settings| settings.tab_size)
    }

    pub fn hard_tabs(&self, language: Option<&str>) -> bool {
        self.language_setting(language, |settings| settings.hard_tabs)
    }

    pub fn soft_wrap(&self, language: Option<&str>) -> SoftWrap {
        self.language_setting(language, |settings| settings.soft_wrap)
    }

    pub fn preferred_line_length(&self, language: Option<&str>) -> u32 {
        self.language_setting(language, |settings| settings.preferred_line_length)
    }

    pub fn format_on_save(&self, language: Option<&str>) -> FormatOnSave {
        self.language_setting(language, |settings| settings.format_on_save.clone())
    }

    pub fn formatter(&self, language: Option<&str>) -> Formatter {
        self.language_setting(language, |settings| settings.formatter.clone())
    }

    pub fn enable_language_server(&self, language: Option<&str>) -> bool {
        self.language_setting(language, |settings| settings.enable_language_server)
    }

    fn language_setting<F, R>(&self, language: Option<&str>, f: F) -> R
    where
        F: Fn(&EditorSettings) -> Option<R>,
    {
        None.or_else(|| language.and_then(|l| self.language_overrides.get(l).and_then(&f)))
            .or_else(|| f(&self.editor_overrides))
            .or_else(|| language.and_then(|l| self.language_defaults.get(l).and_then(&f)))
            .or_else(|| f(&self.editor_defaults))
            .expect("missing default")
    }

    pub fn git_gutter(&self) -> GitGutter {
        self.git_overrides.git_gutter.unwrap_or_else(|| {
            self.git
                .git_gutter
                .expect("git_gutter should be some by setting setup")
        })
    }

    #[cfg(any(test, feature = "test-support"))]
    pub fn test(cx: &gpui::AppContext) -> Settings {
        Settings {
            experiments: FeatureFlags::default(),
            buffer_font_family: cx.font_cache().load_family(&["Monaco"]).unwrap(),
            buffer_font_size: 14.,
            default_buffer_font_size: 14.,
            hover_popover_enabled: true,
            show_completions_on_input: true,
            vim_mode: false,
            autosave: Autosave::Off,
            default_dock_anchor: DockAnchor::Bottom,
            editor_defaults: EditorSettings {
                tab_size: Some(4.try_into().unwrap()),
                hard_tabs: Some(false),
                soft_wrap: Some(SoftWrap::None),
                preferred_line_length: Some(80),
                format_on_save: Some(FormatOnSave::On),
                formatter: Some(Formatter::LanguageServer),
                enable_language_server: Some(true),
            },
            editor_overrides: Default::default(),
            journal_defaults: Default::default(),
            journal_overrides: Default::default(),
            terminal_defaults: Default::default(),
            terminal_overrides: Default::default(),
            git: Default::default(),
            git_overrides: Default::default(),
            language_defaults: Default::default(),
            language_overrides: Default::default(),
            lsp: Default::default(),
            projects_online_by_default: true,
            theme: gpui::fonts::with_font_cache(cx.font_cache().clone(), Default::default),
            staff_mode: false,
        }
    }

    #[cfg(any(test, feature = "test-support"))]
    pub fn test_async(cx: &mut gpui::TestAppContext) {
        cx.update(|cx| {
            let settings = Self::test(cx);
            cx.set_global(settings);
        });
    }
}

pub fn settings_file_json_schema(
    theme_names: Vec<String>,
    language_names: &[String],
) -> serde_json::Value {
    let settings = SchemaSettings::draft07().with(|settings| {
        settings.option_add_null_type = false;
    });
    let generator = SchemaGenerator::new(settings);
    let mut root_schema = generator.into_root_schema_for::<SettingsFileContent>();

    // Create a schema for a theme name.
    let theme_name_schema = SchemaObject {
        instance_type: Some(SingleOrVec::Single(Box::new(InstanceType::String))),
        enum_values: Some(theme_names.into_iter().map(Value::String).collect()),
        ..Default::default()
    };

    // Create a schema for a 'languages overrides' object, associating editor
    // settings with specific langauges.
    assert!(root_schema.definitions.contains_key("EditorSettings"));
    let languages_object_schema = SchemaObject {
        instance_type: Some(SingleOrVec::Single(Box::new(InstanceType::Object))),
        object: Some(Box::new(ObjectValidation {
            properties: language_names
                .iter()
                .map(|name| {
                    (
                        name.clone(),
                        Schema::new_ref("#/definitions/EditorSettings".into()),
                    )
                })
                .collect(),
            ..Default::default()
        })),
        ..Default::default()
    };

    // Add these new schemas as definitions, and modify properties of the root
    // schema to reference them.
    root_schema.definitions.extend([
        ("ThemeName".into(), theme_name_schema.into()),
        ("Languages".into(), languages_object_schema.into()),
    ]);
    let root_schema_object = &mut root_schema.schema.object.as_mut().unwrap();

    // Avoid automcomplete for non-user facing settings
    root_schema_object.properties.remove("staff_mode");
    root_schema_object.properties.extend([
        (
            "theme".to_owned(),
            Schema::new_ref("#/definitions/ThemeName".into()),
        ),
        (
            "languages".to_owned(),
            Schema::new_ref("#/definitions/Languages".into()),
        ),
        // For backward compatibility
        (
            "language_overrides".to_owned(),
            Schema::new_ref("#/definitions/Languages".into()),
        ),
    ]);

    serde_json::to_value(root_schema).unwrap()
}

/// Expects the key to be unquoted, and the value to be valid JSON
/// (e.g. values should be unquoted for numbers and bools, quoted for strings)
pub fn write_top_level_setting(
    mut settings_content: String,
    top_level_key: &str,
    new_val: &str,
) -> String {
    let mut parser = tree_sitter::Parser::new();
    parser.set_language(tree_sitter_json::language()).unwrap();
    let tree = parser.parse(&settings_content, None).unwrap();

    let mut cursor = tree_sitter::QueryCursor::new();

    let query = Query::new(
        tree_sitter_json::language(),
        "
        (document
            (object
                (pair
                    key: (string) @key
                    value: (_) @value)))
    ",
    )
    .unwrap();

    let mut first_key_start = None;
    let mut existing_value_range = None;
    let matches = cursor.matches(&query, tree.root_node(), settings_content.as_bytes());
    for mat in matches {
        if mat.captures.len() != 2 {
            continue;
        }

        let key = mat.captures[0];
        let value = mat.captures[1];

        first_key_start.get_or_insert_with(|| key.node.start_byte());

        if let Some(key_text) = settings_content.get(key.node.byte_range()) {
            if key_text == format!("\"{top_level_key}\"") {
                existing_value_range = Some(value.node.byte_range());
                break;
            }
        }
    }

    match (first_key_start, existing_value_range) {
        (None, None) => {
            // No document, create a new object and overwrite
            settings_content.clear();
            write!(
                settings_content,
                "{{\n    \"{}\": {new_val}\n}}\n",
                top_level_key
            )
            .unwrap();
        }

        (_, Some(existing_value_range)) => {
            // Existing theme key, overwrite
            settings_content.replace_range(existing_value_range, &new_val);
        }

        (Some(first_key_start), None) => {
            // No existing theme key, but other settings. Prepend new theme settings and
            // match style of first key
            let mut row = 0;
            let mut column = 0;
            for (ix, char) in settings_content.char_indices() {
                if ix == first_key_start {
                    break;
                }
                if char == '\n' {
                    row += 1;
                    column = 0;
                } else {
                    column += char.len_utf8();
                }
            }

            let content = format!(r#""{top_level_key}": {new_val},"#);
            settings_content.insert_str(first_key_start, &content);

            if row > 0 {
                settings_content.insert_str(
                    first_key_start + content.len(),
                    &format!("\n{:width$}", ' ', width = column),
                )
            } else {
                settings_content.insert_str(first_key_start + content.len(), " ")
            }
        }
    }

    settings_content
}

fn merge<T: Copy>(target: &mut T, value: Option<T>) {
    if let Some(value) = value {
        *target = value;
    }
}

pub fn parse_json_with_comments<T: DeserializeOwned>(content: &str) -> Result<T> {
    Ok(serde_json::from_reader(
        json_comments::CommentSettings::c_style().strip_comments(content.as_bytes()),
    )?)
}

#[cfg(test)]
mod tests {
    use crate::write_top_level_setting;
    use unindent::Unindent;

    #[test]
    fn test_write_theme_into_settings_with_theme() {
        let settings = r#"
            {
                "theme": "one-dark"
            }
        "#
        .unindent();

        let new_settings = r#"
            {
                "theme": "summerfruit-light"
            }
        "#
        .unindent();

        let settings_after_theme =
            write_top_level_setting(settings, "theme", "\"summerfruit-light\"");

        assert_eq!(settings_after_theme, new_settings)
    }

    #[test]
    fn test_write_theme_into_empty_settings() {
        let settings = r#"
            {
            }
        "#
        .unindent();

        let new_settings = r#"
            {
                "theme": "summerfruit-light"
            }
        "#
        .unindent();

        let settings_after_theme =
            write_top_level_setting(settings, "theme", "\"summerfruit-light\"");

        assert_eq!(settings_after_theme, new_settings)
    }

    #[test]
    fn test_write_theme_into_no_settings() {
        let settings = "".to_string();

        let new_settings = r#"
            {
                "theme": "summerfruit-light"
            }
        "#
        .unindent();

        let settings_after_theme =
            write_top_level_setting(settings, "theme", "\"summerfruit-light\"");

        assert_eq!(settings_after_theme, new_settings)
    }

    #[test]
    fn test_write_theme_into_single_line_settings_without_theme() {
        let settings = r#"{ "a": "", "ok": true }"#.to_string();
        let new_settings = r#"{ "theme": "summerfruit-light", "a": "", "ok": true }"#;

        let settings_after_theme =
            write_top_level_setting(settings, "theme", "\"summerfruit-light\"");

        assert_eq!(settings_after_theme, new_settings)
    }

    #[test]
    fn test_write_theme_pre_object_whitespace() {
        let settings = r#"          { "a": "", "ok": true }"#.to_string();
        let new_settings = r#"          { "theme": "summerfruit-light", "a": "", "ok": true }"#;

        let settings_after_theme =
            write_top_level_setting(settings, "theme", "\"summerfruit-light\"");

        assert_eq!(settings_after_theme, new_settings)
    }

    #[test]
    fn test_write_theme_into_multi_line_settings_without_theme() {
        let settings = r#"
            {
                "a": "b"
            }
        "#
        .unindent();

        let new_settings = r#"
            {
                "theme": "summerfruit-light",
                "a": "b"
            }
        "#
        .unindent();

        let settings_after_theme =
            write_top_level_setting(settings, "theme", "\"summerfruit-light\"");

        assert_eq!(settings_after_theme, new_settings)
    }
}