import Foundation

/// Language identification for syntax highlighting and file/content rendering.
///
/// Maps file extensions and markdown fence names to language-specific
/// highlighting rules. Kept in OppiCore so iOS and Mac choose the same
/// renderer for code, Markdown fences, diffs, and document formats.
enum SyntaxLanguage: Sendable, Hashable {
    case swift
    case typescript
    case javascript
    case python
    case go
    case rust
    case ruby
    case shell
    case html
    case css
    case json
    case yaml
    case toml
    case sql
    case c
    case cpp
    case java
    case kotlin
    case zig
    case xml
    case protobuf
    case graphql
    case diff
    case latex
    case orgMode
    case mermaid
    case dot
    case unknown

    /// Detect language from file extension or code fence name.
    static func detect(_ identifier: String) -> Self {
        switch identifier.lowercased() {
        case "swift": return .swift
        case "ts", "tsx", "mts", "cts", "typescript": return .typescript
        case "js", "jsx", "mjs", "cjs", "javascript": return .javascript
        case "py", "pyi", "pyw", "python": return .python
        case "go", "golang": return .go
        case "rs", "rust": return .rust
        case "rb", "erb", "ruby": return .ruby
        case "sh", "bash", "zsh", "fish", "ksh", "csh", "shell": return .shell
        case "html", "htm": return .html
        case "css", "scss", "less", "sass": return .css
        case "json", "jsonl", "geojson", "jsonc": return .json
        case "yaml", "yml": return .yaml
        case "toml": return .toml
        case "sql": return .sql
        case "c", "h": return .c
        case "cpp", "cc", "cxx", "hpp", "hxx", "hh", "c++": return .cpp
        case "java": return .java
        case "kt", "kts", "kotlin": return .kotlin
        case "zig": return .zig
        case "xml", "xsl", "xslt", "xsd", "plist", "xcscheme", "xcworkspacedata",
             "storyboard", "xib", "csproj", "vcxproj", "sln": return .xml
        case "proto", "protobuf": return .protobuf
        case "graphql", "gql": return .graphql
        case "diff", "patch": return .diff
        case "tex", "latex", "math": return .latex
        case "org": return .orgMode
        case "mmd", "mermaid": return .mermaid
        case "dot", "gv": return .dot
        default: return .unknown
        }
    }

    var displayName: String {
        switch self {
        case .swift: return "Swift"
        case .typescript: return "TypeScript"
        case .javascript: return "JavaScript"
        case .python: return "Python"
        case .go: return "Go"
        case .rust: return "Rust"
        case .ruby: return "Ruby"
        case .shell: return "Shell"
        case .html: return "HTML"
        case .css: return "CSS"
        case .json: return "JSON"
        case .yaml: return "YAML"
        case .toml: return "TOML"
        case .sql: return "SQL"
        case .c: return "C"
        case .cpp: return "C++"
        case .java: return "Java"
        case .kotlin: return "Kotlin"
        case .zig: return "Zig"
        case .xml: return "XML"
        case .protobuf: return "Protobuf"
        case .graphql: return "GraphQL"
        case .diff: return "Diff"
        case .latex: return "LaTeX"
        case .orgMode: return "Org"
        case .mermaid: return "Mermaid"
        case .dot: return "Graphviz"
        case .unknown: return "Text"
        }
    }

    var lineCommentPrefix: [Character]? {
        switch self {
        case .swift, .typescript, .javascript, .go, .rust, .c, .cpp, .java, .kotlin, .zig, .css,
             .protobuf, .graphql:
            return ["/", "/"]
        case .python, .ruby, .shell, .yaml, .toml:
            return ["#"]
        case .sql:
            return ["-", "-"]
        case .latex:
            return ["%"]
        case .orgMode:
            return ["#"]
        case .mermaid:
            return ["%", "%"]
        case .dot:
            return ["/", "/"]
        case .html, .json, .xml, .diff, .unknown:
            return nil
        }
    }

    var hasBlockComments: Bool {
        switch self {
        case .swift, .typescript, .javascript, .go, .rust, .c, .cpp, .java, .kotlin, .zig, .css,
             .protobuf, .graphql, .dot:
            return true
        case .xml:
            return true // <!-- --> handled by XML scanner
        default:
            return false
        }
    }

    var keywords: Set<String> {
        switch self {
        case .swift:
            return swiftKeywords
        case .typescript, .javascript:
            return tsKeywords
        case .python:
            return pythonKeywords
        case .go:
            return goKeywords
        case .rust:
            return rustKeywords
        case .ruby:
            return rubyKeywords
        case .shell:
            return shellKeywords
        case .sql:
            return sqlKeywords
        case .c, .cpp:
            return cKeywords
        case .java:
            return javaKeywords
        case .kotlin:
            return kotlinKeywords
        case .zig:
            return zigKeywords
        case .protobuf:
            return protobufKeywords
        case .graphql:
            return graphqlKeywords
        case .latex:
            return latexKeywords
        case .orgMode:
            return orgModeKeywords
        case .mermaid:
            return mermaidKeywords
        case .dot:
            return dotKeywords
        case .html, .css, .json, .yaml, .toml, .xml, .diff, .unknown:
            return []
        }
    }
}