import type { EditedFiles, FileOperation } from "./file_ops";

import { createTwoFilesPatch } from "diff";

/**************************************

* ANSI color codes for output styling

**************************************/

const RED = "\u001b[31m";

const GREEN = "\u001b[32m";

const CYAN = "\u001b[36m";

const YELLOW = "\u001b[33m";

const RESET = "\u001b[0m";

/******************************************************

* Generate a unified diff of two file contents

* akin to generate_file_diff(original, updated)

******************************************************/

export function generateFileDiff(

originalContent: string,

updatedContent: string,

filePath: string,

): string {

return createTwoFilesPatch(

`${filePath} (original)`,

`${filePath} (modified)`,

originalContent,

updatedContent,

undefined,

undefined,

{ context: 5 },

);

}

/******************************************************

* Apply colorization to a unified diff

* akin to generate_colored_diff(diff_content)

******************************************************/

export function generateColoredDiff(diffContent: string): string {

const lines = diffContent.split(/\r?\n/);

const coloredLines: Array<string> = [];

for (const line of lines) {

if (line.startsWith("+++") || line.startsWith("---")) {

// keep these lines uncolored, preserving the original style

coloredLines.push(line);

} else if (line.startsWith("+")) {

// color lines that begin with + but not +++

coloredLines.push(`${GREEN}${line}${RESET}`);

} else if (line.startsWith("-")) {

// color lines that begin with - but not ---

coloredLines.push(`${RED}${line}${RESET}`);

} else if (line.startsWith("@@")) {

// hunk header

coloredLines.push(`${CYAN}${line}${RESET}`);

} else {

coloredLines.push(line);

}

}

return coloredLines.join("\n");

}

/******************************************************

* Count lines added and removed in a unified diff.

* akin to generate_diff_stats(diff_content).

******************************************************/

export function generateDiffStats(diffContent: string): [number, number] {

let linesAdded = 0;

let linesRemoved = 0;

const lines = diffContent.split(/\r?\n/);

for (const line of lines) {

if (line.startsWith("+") && !line.startsWith("+++")) {

linesAdded += 1;

} else if (line.startsWith("-") && !line.startsWith("---")) {

linesRemoved += 1;

}

}

return [linesAdded, linesRemoved];

}

/************************************************

* Helper for generating a short header block

************************************************/

function generateDiffHeader(fileOp: FileOperation): string {

const TTY_WIDTH = 80;

const separatorLine = "=".repeat(TTY_WIDTH) + "\n";

const subSeparatorLine = "-".repeat(TTY_WIDTH) + "\n";

const headerLine = `Changes for: ${fileOp.path}`;

return separatorLine + headerLine + "\n" + subSeparatorLine;

}

/****************************************************************

* Summarize diffs for each file operation that has differences.

* akin to generate_diff_summary(edited_files, original_files)

****************************************************************/

export function generateDiffSummary(

editedFiles: EditedFiles,

originalFileContents: Record<string, string>,

): [string, Array<FileOperation>] {

let combinedDiffs = "";

const opsToApply: Array<FileOperation> = [];

for (const fileOp of editedFiles.ops) {

const diffHeader = generateDiffHeader(fileOp);

if (fileOp.delete) {

// file will be deleted

combinedDiffs += diffHeader + "File will be deleted.\n\n";

opsToApply.push(fileOp);

continue;

} else if (fileOp.move_to) {

combinedDiffs +=

diffHeader + `File will be moved to: ${fileOp.move_to}\n\n`;

opsToApply.push(fileOp);

continue;

}

// otherwise it's an update

const originalContent = originalFileContents[fileOp.path] ?? "";

const updatedContent = fileOp.updated_full_content ?? "";

if (originalContent === updatedContent) {

// no changes => skip

continue;

}

const diffOutput = generateFileDiff(

originalContent,

updatedContent,

fileOp.path,

);

if (diffOutput.trim()) {

const coloredDiff = generateColoredDiff(diffOutput);

combinedDiffs += diffHeader + coloredDiff + "\n";

opsToApply.push(fileOp);

}

}

return [combinedDiffs, opsToApply];

}

/****************************************************************

* Generate a user-friendly summary of the pending file ops.

* akin to generate_edit_summary(ops_to_apply, original_files)

****************************************************************/

export function generateEditSummary(

opsToApply: Array<FileOperation>,

originalFileContents: Record<string, string>,

): string {

if (!opsToApply || opsToApply.length === 0) {

return "No changes detected.";

}

const summaryLines: Array<string> = [];

for (const fileOp of opsToApply) {

if (fileOp.delete) {

// red for deleted

summaryLines.push(`${RED} Deleted: ${fileOp.path}${RESET}`);

} else if (fileOp.move_to) {

// yellow for moved

summaryLines.push(

`${YELLOW} Moved: ${fileOp.path} -> ${fileOp.move_to}${RESET}`,

);

} else {

const originalContent = originalFileContents[fileOp.path];

const updatedContent = fileOp.updated_full_content ?? "";

if (originalContent === undefined) {

// newly created file

const linesAdded = updatedContent.split(/\r?\n/).length;

summaryLines.push(

`${GREEN} Created: ${fileOp.path} (+${linesAdded} lines)${RESET}`,

);

} else {

const diffOutput = generateFileDiff(

originalContent,

updatedContent,

fileOp.path,

);

const [added, removed] = generateDiffStats(diffOutput);

summaryLines.push(

` Modified: ${fileOp.path} (${GREEN}+${added}${RESET}/${RED}-${removed}${RESET})`,

);

}

}

}

return summaryLines.join("\n");

}