import Foundation
import OpenAIService
import SuggestionModel
import XcodeInspector
import Preferences

final class DynamicContextController {
    let chatGPTService: any ChatGPTServiceType

    init(chatGPTService: any ChatGPTServiceType) {
        self.chatGPTService = chatGPTService
    }

    func updatePromptToMatchContent(systemPrompt: String) async throws {
        let language = UserDefaults.shared.value(for: \.chatGPTLanguage)
        let content = getEditorInformation()
        let relativePath = content.documentURL.path
            .replacingOccurrences(of: content.projectURL.path, with: "")
        let selectionRange = content.editorContent?.selections.first ?? .outOfScope
        let contextualSystemPrompt = """
        \(language.isEmpty ? "" : "You must always reply in \(language)")
        \(systemPrompt)

        Active Document Context:###
        Document Relative Path: \(relativePath)
        Selection Range Start: \
        Line \(selectionRange.start.line) \
        Character \(selectionRange.start.character)
        Selection Range End: \
        Line \(selectionRange.end.line) \
        Character \(selectionRange.end.character)
        Cursor Position: \
        Line \(selectionRange.end.line) \
        Character \(selectionRange.end.character)
        Selected Code (start from line \(selectionRange.end.line)):```\(content.language.rawValue)
        \(content.selectedContent)
        ```

        Line Annotations:
        \(content.editorContent?.lineAnnotations.map { "- \($0)" }.joined(separator: "\n") ?? "N/A")
        ###
        """
        await chatGPTService.mutateSystemPrompt(contextualSystemPrompt)
    }
}

extension DynamicContextController {
    struct Information {
        let editorContent: SourceEditor.Content?
        let selectedContent: String
        let documentURL: URL
        let projectURL: URL
        let language: CodeLanguage
    }

    func getEditorInformation() -> Information {
        let editorContent = XcodeInspector.shared.focusedEditor?.content
        let documentURL = XcodeInspector.shared.activeDocumentURL
        let projectURL = XcodeInspector.shared.activeProjectURL
        let language = languageIdentifierFromFileURL(documentURL)

        if let editorContent, let range = editorContent.selections.first {
            let startIndex = min(
                max(0, range.start.line),
                editorContent.lines.endIndex - 1
            )
            let endIndex = min(
                max(startIndex, range.end.line),
                editorContent.lines.endIndex - 1
            )
            let selectedContent = editorContent.lines[startIndex...endIndex]
            return .init(
                editorContent: editorContent,
                selectedContent: selectedContent.joined(),
                documentURL: documentURL,
                projectURL: projectURL,
                language: language
            )
        }

        return .init(
            editorContent: editorContent,
            selectedContent: "",
            documentURL: documentURL,
            projectURL: projectURL,
            language: language
        )
    }
}