#!/usr/bin/env bash
set -e

# Add OpenTofu binary to PATH
export PATH="${PATH}:/home/runner/.opentofu/bin"

# Read inputs
COMMAND=$1
INPUT=$2
EXIT_CODE=$3
WORKING_DIR=$4

# Determine repo root (where .git exists)
REPO_ROOT=$(git rev-parse --show-toplevel 2>/dev/null || echo "$PWD")

# Change to working directory if provided, relative to repo root
if [[ -n "$WORKING_DIR" ]]; then
    TARGET_DIR="$REPO_ROOT/$WORKING_DIR"
    echo "Switching to working directory: $TARGET_DIR"
    cd "$TARGET_DIR" || { echo "Directory $TARGET_DIR not found"; exit 1; }
else
    cd "$REPO_ROOT" || { echo "Cannot determine repo root"; exit 1; }
fi

# Strip ANSI codes from input
# INPUT=$(echo "$INPUT" | sed 's/\x1b\[[0-9;]*m//g')

##################
# CI Detection
##################
if [[ -n "$GITHUB_ACTIONS" ]]; then
    CI_PLATFORM="github"
elif [[ -n "$GITEA_ACTION" ]]; then
    CI_PLATFORM="gitea"
else
    CI_PLATFORM="local"
fi
echo "Detected CI platform: $CI_PLATFORM"

##################
# PR Variables
##################
if [[ "$CI_PLATFORM" == "github" ]]; then
    : "${PR_NUMBER:?PR_NUMBER not set}"
    : "${PR_COMMENTS_URL:?PR_COMMENTS_URL not set}"
    : "${PR_COMMENT_URI:?PR_COMMENT_URI not set}"
    AUTH_HEADER="Authorization: token $GITHUB_TOKEN"
elif [[ "$CI_PLATFORM" == "gitea" ]]; then
    : "${PR_NUMBER:?PR_NUMBER not set}"
    : "${PR_COMMENTS_URL:?PR_COMMENTS_URL not set}"
    : "${PR_COMMENT_URI:?PR_COMMENT_URI not set}"
    : "${GITEA_TOKEN:?GITEA_TOKEN not set}"
    AUTH_HEADER="Authorization: token $GITEA_TOKEN"
else
    echo "Local mode: PR variables must be set manually."
    exit 1
fi

ACCEPT_HEADER="Accept: application/vnd.github.v3+json"
CONTENT_HEADER="Content-Type: application/json"

##################
# Shared Settings
##################
DETAILS_STATE=" open"
COLOURISE=${HIGHLIGHT_CHANGES:-true}

##################
# Helper Functions
##################
handle_pr_comment() {
    local type="$1"
    local body="$2"

    PR_COMMENT_ID=$(curl -sS -H "$AUTH_HEADER" -H "$ACCEPT_HEADER" -L "$PR_COMMENTS_URL" \
        | jq ".[] | select(.body|test(\"### tofu \\\`$type\\\`\")) | .id")

    if [[ "$PR_COMMENT_ID" ]]; then
        echo "Updating existing $type PR comment: $PR_COMMENT_ID"
        PR_COMMENT_URL="$PR_COMMENT_URI/$PR_COMMENT_ID"
        PR_PAYLOAD=$(jq -n --arg body "$body" '{body: $body}')
        curl -sS -X PATCH -H "$AUTH_HEADER" -H "$ACCEPT_HEADER" -H "$CONTENT_HEADER" \
            -d "$PR_PAYLOAD" -L "$PR_COMMENT_URL" > /dev/null
    else
        echo "Creating new $type PR comment"
        PR_PAYLOAD=$(jq -n --arg body "$body" '{body: $body}')
        curl -sS -X POST -H "$AUTH_HEADER" -H "$ACCEPT_HEADER" -H "$CONTENT_HEADER" \
            -d "$PR_PAYLOAD" -L "$PR_COMMENTS_URL" > /dev/null
    fi
}

format_diff_block() {
    local content="$1"
    local codeblock=""
    if [[ $CI_PLATFORM == "github" && $COLOURISE == "true" ]]; then
        content=$(echo "$content" | sed -r 's/^~/!/g')
        codeblock="diff"
    fi
    echo "```$codeblock
$content
```"
}

##################
# Command Handlers
##################
case "$COMMAND" in

fmt)
    STATUS="Succeeded"
    [[ "$COMMENTER_EXITCODE" -ne 0 ]] && STATUS="Failed"

    ALL_DIFFS=""
    # COMMENTER_INPUT is expected to be a newline-separated file list
    while IFS= read -r file; do
        if [[ -n "$file" && -f "$file" ]]; then
            FILE_DIFF=$(tofu fmt -no-color -write=false -diff "$file" 2>/dev/null || true)
            DIFF_BLOCK=$(format_diff_block "$FILE_DIFF")
            ALL_DIFFS="$ALL_DIFFS
<details$DETAILS_STATE><summary><code>$file</code></summary>

$DIFF_BLOCK
</details>"
        fi
    done <<< "$COMMENTER_INPUT"

    # Fallback if no valid files found
    [[ -z "$ALL_DIFFS" ]] && ALL_DIFFS=$(format_diff_block "$COMMENTER_INPUT")

    PR_COMMENT="### tofu \`fmt\` $STATUS for Workspace: \`$WORKSPACE\`
$ALL_DIFFS"
    handle_pr_comment "$COMMAND" "$PR_COMMENT"
    ;;

plan)
    STATUS="Succeeded"
    [[ "$COMMENTER_EXITCODE" -ne 0 ]] && STATUS="Failed"
    PR_OUTPUT=$(format_diff_block "$COMMENTER_INPUT")
    PR_COMMENT="### tofu \`plan\` $STATUS for Workspace: \`$WORKSPACE\`
<details$DETAILS_STATE><summary>Show Output</summary>

$PR_OUTPUT
</details>"
    handle_pr_comment "$COMMAND" "$PR_COMMENT"
    ;;

init|validate)
    STATUS="Succeeded"
    [[ "$COMMENTER_EXITCODE" -ne 0 ]] && STATUS="Failed"
    PR_COMMENT="### tofu \`$COMMAND\` $STATUS for Workspace: \`$WORKSPACE\`
<details$DETAILS_STATE><summary>Show Output</summary>

\`\`\`
$COMMENTER_INPUT
\`\`\`
</details>"
    handle_pr_comment "$COMMAND" "$PR_COMMENT"
    ;;

*)
    echo "Unsupported command: $COMMAND"
    exit 1
    ;;
esac