#!/bin/bash
# milestone-create.sh - Create milestones on Gitea or GitHub
# Usage: milestone-create.sh -t "Title" [-d "Description"] [--due "YYYY-MM-DD"]

set -e
set -o pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
source "$SCRIPT_DIR/detect-platform.sh"

# Default values
TITLE=""
DESCRIPTION=""
DUE_DATE=""
LIST_ONLY=false

usage() {
    cat <<EOF
Usage: $(basename "$0") [OPTIONS]

Create or list milestones on the current repository (Gitea or GitHub).

Versioning Convention:
    - Features get dedicated milestones
    - Pre-MVP milestones MUST use 0.0.x and MUST start at 0.0.1
    - 0.1.0 is reserved for MVP release
    - After MVP, continue semantic progression (0.1.x, 0.2.x, ...)

Options:
    -t, --title TITLE       Milestone title/version (e.g., "0.0.1")
    -d, --desc DESCRIPTION  Milestone description
    --due DATE              Due date (YYYY-MM-DD format)
    --list                  List existing milestones
    -h, --help              Show this help message

Examples:
    $(basename "$0") --list
    $(basename "$0") -t "0.0.1" -d "Pre-MVP Foundation Sprint"
    $(basename "$0") -t "0.1.0" -d "MVP Release" --due "2025-03-01"
EOF
    exit "${1:-2}"
}

# Parse arguments
# Usage-error contract (R4, 2026-08-28): usage errors print to STDERR and exit 2,
# distinct from provider, credential, and verification failures (exit 1).
usage_error() {
    echo "Error: $*" >&2
    usage >&2
}

while [[ $# -gt 0 ]]; do
    case $1 in
        -t|--title)
            [[ $# -ge 2 && "$2" != - && "$2" != --* && ! "$2" =~ ^-[[:alnum:]] ]] || usage_error "option $1 requires a value (option-like values are rejected; bare - is reserved)"
            TITLE="$2"
            shift 2
            ;;
        -d|--desc)
            [[ $# -ge 2 && "$2" != - && "$2" != --* && ! "$2" =~ ^-[[:alnum:]] ]] || usage_error "option $1 requires a value (option-like values are rejected; bare - is reserved)"
            DESCRIPTION="$2"
            shift 2
            ;;
        --due)
            [[ $# -ge 2 && "$2" != - && "$2" != --* && ! "$2" =~ ^-[[:alnum:]] ]] || usage_error "option $1 requires a value (option-like values are rejected; bare - is reserved)"
            DUE_DATE="$2"
            shift 2
            ;;
        --list)
            LIST_ONLY=true
            shift
            ;;
        -h|--help)
            usage 0
            ;;
        *)
            echo "Unknown option: $1" >&2
            usage
            ;;
    esac
done

PLATFORM=$(detect_platform)

if [[ "$LIST_ONLY" == true ]]; then
    case "$PLATFORM" in
        github)
            prov_rc=0
            gh api repos/:owner/:repo/milestones --jq '.[] | "\(.number)\t\(.title)\t\(.state)\t\(.open_issues)/\(.closed_issues) issues"' || prov_rc=$?
            [[ "$prov_rc" -eq 0 ]] || { echo "Error: provider command failed (exit ${prov_rc}; provider failure, not a usage error)" >&2; exit 1; }
            ;;
        gitea)
            REPO_ARGS=$(get_gitea_repo_args) || {
                echo "Error: Could not resolve Gitea repo/login for remote host" >&2
                exit 1
            }
            prov_rc=0
            tea milestones list $REPO_ARGS || prov_rc=$?
            [[ "$prov_rc" -eq 0 ]] || { echo "Error: provider command failed (exit ${prov_rc}; provider failure, not a usage error)" >&2; exit 1; }
            ;;
        *)
            echo "Error: Could not detect git platform" >&2
            exit 1
            ;;
    esac
    exit 0
fi

if [[ -z "$TITLE" ]]; then
    usage_error "Title is required (-t) for creating milestones"
fi

case "$PLATFORM" in
    github)
        # GitHub uses the API for milestone creation
        # Use jq to safely construct JSON so titles/descriptions containing
        # quotes or special characters do not corrupt the payload (F-07).
        JSON_PAYLOAD=$(jq -n \
            --arg t "$TITLE" \
            --arg d "$DESCRIPTION" \
            --arg due "${DUE_DATE}" \
            '{"title": $t}
             + (if $d != "" then {"description": $d} else {} end)
             + (if $due != "" then {"due_on": ($due + "T00:00:00Z")} else {} end)')

        prov_rc=0
        gh api repos/:owner/:repo/milestones --method POST --input - <<< "$JSON_PAYLOAD" || prov_rc=$?
        [[ "$prov_rc" -eq 0 ]] || { echo "Error: provider command failed (exit ${prov_rc}; provider failure, not a usage error)" >&2; exit 1; }
        echo "Milestone '$TITLE' created successfully"
        ;;
    gitea)
        REPO_ARGS=$(get_gitea_repo_args) || {
            echo "Error: Could not resolve Gitea repo/login for remote host" >&2
            exit 1
        }
        CMD=(tea milestones create --title "$TITLE")
        [[ -n "$DESCRIPTION" ]] && CMD+=(--description "$DESCRIPTION")
        [[ -n "$DUE_DATE" ]] && CMD+=(--deadline "$DUE_DATE")
        prov_rc=0
        "${CMD[@]}" $REPO_ARGS || prov_rc=$?
        [[ "$prov_rc" -eq 0 ]] || { echo "Error: provider command failed (exit ${prov_rc}; provider failure, not a usage error)" >&2; exit 1; }
        echo "Milestone '$TITLE' created successfully"
        ;;
    *)
        echo "Error: Could not detect git platform" >&2
        exit 1
        ;;
esac