#!/bin/bash
# build.sh - gumx.cc static site generator
# Licensed under the MIT License (see LICENSES/MIT)

# Must be run directly, not sourced
[[ "$(basename "${0}")" == "build.sh" ]] || { echo "Do not source build.sh"; exit 1; }

set -euo pipefail

# ---------------------------------------------------------------------------
# Source mo mustache renderer
# ---------------------------------------------------------------------------
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
if [[ ! -f "${SCRIPT_DIR}/mo" ]]; then
    echo "[error] mo not found. Run: curl -sL https://raw.githubusercontent.com/tests-always-included/mo/master/mo -o mo && chmod +x mo" >&2
    exit 1
fi
# shellcheck source=mo
. "${SCRIPT_DIR}/mo"

# ---------------------------------------------------------------------------
# Defaults
# ---------------------------------------------------------------------------
VERBOSE=false
DRAFTS=false
FORCE=false
DO_CLEAN=false
DO_PREP=false
DO_SERVE=false

LIST_COUNT=5

TMPDIR_BUILD="$(mktemp -d)"

# ---------------------------------------------------------------------------
# Cleanup trap
# ---------------------------------------------------------------------------
cleanup() {
    rm -rf "${TMPDIR_BUILD}"
}
trap cleanup EXIT INT TERM

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

Options:
  -h, --help      Show this help message
  -v, --verbose   Verbose output
  -d, --drafts    Include undated posts (marked [DRAFT])
  -f, --force     Force rebuild of all pages
  -c, --clean     Remove output/ and exit
  -p, --prep      Optimize untracked images and fix markdown trailing newlines
  -s, --serve     After building, serve output/ on port 8080 with darkhttpd
EOF
}

while [[ $# -gt 0 ]]; do
    case "$1" in
        -h|--help)   usage; exit 0 ;;
        -v|--verbose) VERBOSE=true ;;
        -d|--drafts)  DRAFTS=true ;;
        -f|--force)   FORCE=true ;;
        -c|--clean)   DO_CLEAN=true ;;
        -p|--prep)    DO_PREP=true ;;
        -s|--serve)   DO_SERVE=true ;;
        *) echo "[error] Unknown option: $1" >&2; usage; exit 1 ;;
    esac
    shift
done

# ---------------------------------------------------------------------------
# --clean
# ---------------------------------------------------------------------------
if [[ "${DO_CLEAN}" == true ]]; then
    rm -rf output
    echo "[clean] output/ removed"
    exit 0
fi

# ---------------------------------------------------------------------------
# --prep  (absorbed from prep.sh)
# ---------------------------------------------------------------------------
if [[ "${DO_PREP}" == true ]]; then
    echo "[prep] Optimizing untracked images..."
    for img in $(git ls-files -o images/ 2>/dev/null); do
        if identify "${img}" > /dev/null 2>&1; then
            mogrify -strip -resize 800x "${img}"
            echo "[prep:processed] ${img}"
        else
            echo "[prep:ignored] ${img}"
        fi
    done

    echo "[prep] Adding trailing newlines to .md files..."
    local _prep_list
    _prep_list="$(mktemp)"
    find . -name '*.md' -not -path './.git/*' -not -path './mo/*' -print0 > "${_prep_list}"
    while IFS= read -r -d '' f; do
        if [[ -s "${f}" ]]; then
            last_char="$(tail -c1 "${f}")"
            if [[ "${last_char}" != "" ]]; then
                printf '\n' >> "${f}"
                echo "[prep:newline] ${f}"
            fi
        fi
    done < "${_prep_list}"
    rm -f "${_prep_list}"
fi

# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------
log() {
    if [[ "${VERBOSE}" == true ]]; then echo "$*"; fi
}

# needs_rebuild src dst [template]
# Returns 0 (true / do rebuild) if dst is missing or older than src/template
# Returns 1 (false / skip) if dst is up-to-date and --force is not set
needs_rebuild() {
    local src="$1" dst="$2" tmpl="${3:-}"
    [[ "${FORCE}" == true ]] && return 0
    [[ ! -f "${dst}" ]] && return 0
    [[ "${src}" -nt "${dst}" ]] && return 0
    [[ -n "${tmpl}" && -f "${tmpl}" && "${tmpl}" -nt "${dst}" ]] && return 0
    return 1
}

# render_page template outfile
# All variables exported before calling this function are available.
render_page() {
    local template="$1"
    local outfile="$2"
    mkdir -p "$(dirname "${outfile}")"
    # Copy template into partials/ so mo resolves {{> partial}} relative to that dir,
    # then remove the copy. Avoids any /dev/stdin or /dev/fd dependency.
    local _tmpl_name="${template##templates/}"
    cp "${template}" "templates/partials/${_tmpl_name}"
    (cd templates/partials && mo "${_tmpl_name}") > "${outfile}"
    rm -f "templates/partials/${_tmpl_name}"
}

# build_breadcrumbs path  ->  sets BREADCRUMBS variable
build_breadcrumbs() {
    local path="$1"
    BREADCRUMBS=""
    local components="${path}"
    while [[ "${components}" != "." ]]; do
        BREADCRUMBS=" / <a href=\"/${components}\">$(basename "${components}")</a>${BREADCRUMBS}"
        components="$(dirname "${components}")"
    done
}

# get_frontmatter key file
get_frontmatter() {
    local key="$1" file="$2"
    # lowdown extracts YAML frontmatter fields
    lowdown -X "${key}" "${file}" 2>/dev/null || true
}

# check_has_code content_html  ->  sets HAS_CODE ("true" or "")
check_has_code() {
    local html="$1"
    if echo "${html}" | grep -qE '<pre><code|<code class='; then
        HAS_CODE="true"
    else
        HAS_CODE=""
    fi
}

# render_content_page src_md out_html template_file [header_extra] [lang]
render_content_page() {
    local src_md="$1"
    local out_html="$2"
    local template_file="$3"
    local header_extra="${4:-}"
    local lang="${5:-en}"

    if ! needs_rebuild "${src_md}" "${out_html}" "${template_file}"; then
        log "[skip] ${out_html}"
        return
    fi

    local page_title
    page_title="$(get_frontmatter title "${src_md}")"

    local content
    content="$(lowdown "${src_md}")"

    check_has_code "${content}"

    # Derive output path without "output/" prefix and without "/index.html" suffix
    local rel_path
    rel_path="${out_html#output/}"          # e.g. blog/hello/index.html
    rel_path="${rel_path%/index.html}"      # e.g. blog/hello

    build_breadcrumbs "${rel_path}"

    # Export variables for mo
    export PAGE_TITLE="${page_title}"
    export CONTENT="${content}"
    export BREADCRUMBS
    export HEADER_EXTRA="${header_extra}"
    export META_DATE="${header_extra}"
    export META_DESCRIPTION=""
    export HAS_CODE
    export LANG="${lang}"
    export DIR=""
    [[ "${lang}" == "ar" ]] && export DIR="rtl"
    export IS_HOME=""
    export ARCHIVE_TITLE=""

    render_page "${template_file}" "${out_html}"
    echo "[built] ${out_html}"
}

# ---------------------------------------------------------------------------
# process_content dir template_type archive_title date_required
# Handles blog, talks, code, recipes
# ---------------------------------------------------------------------------
process_content() {
    local dir="$1"
    local template_type="$2"
    local archive_title="$3"
    local date_required="$4"   # "true" or "false"

    if [[ ! -d "${dir}" ]]; then
        log "[info] ${dir}/ directory not found, skipping"
        return
    fi

    local list_file="${TMPDIR_BUILD}/${dir}.list.md"
    : > "${list_file}"

    local _find_list="${TMPDIR_BUILD}/${dir}.find.list"
    find "${dir}" -mindepth 1 -maxdepth 1 -name '*.md' -not -name '.*' -print0 | sort -z > "${_find_list}"

    while IFS= read -r -d '' src; do
        local filename
        filename="$(basename "${src}")"
        local title date lang event header_extra
        title="$(get_frontmatter title "${src}")"
        date="$(get_frontmatter date "${src}")"
        lang="$(get_frontmatter lang "${src}")"
        event="$(get_frontmatter event "${src}")"

        # Derive URL path
        local rel="${src#${dir}/}"     # e.g. hello.md
        local slug="${rel%.md}"        # e.g. hello
        local url_path="/${dir}/${slug}"
        local out_dir="output/${dir}/${slug}"
        local out_html="${out_dir}/index.html"

        # Draft handling
        if [[ "${date_required}" == "true" && -z "${date}" ]]; then
            if [[ "${DRAFTS}" == true ]]; then
                title="[DRAFT] ${title}"
                printf -- '- [DRAFT] [%s](%s)\n' "${title}" "${url_path}" >> "${list_file}"
                echo "[draft] ${src}"
            else
                log "[skipped-draft] ${src}"
                continue
            fi
        else
            if [[ -n "${date}" ]]; then
                if [[ -n "${event}" ]]; then
                    printf -- '- [%s] [%s](%s) @ %s\n' "${date}" "${title}" "${url_path}" "${event}" >> "${list_file}"
                else
                    printf -- '- [%s] [%s](%s)\n' "${date}" "${title}" "${url_path}" >> "${list_file}"
                fi
            else
                printf -- '- [%s](%s)\n' "${title}" "${url_path}" >> "${list_file}"
            fi
        fi

        # Build the page
        header_extra="${date}"
        [[ -n "${event}" ]] && header_extra="${date}${date:+ — }${event}"

        local tmpl="templates/${template_type}.html"
        render_content_page "${src}" "${out_html}" "${tmpl}" "${header_extra}" "${lang:-en}"
        echo "[${template_type}] ${url_path}"

    done < "${_find_list}"

    # Build archive page
    local archive_md="${TMPDIR_BUILD}/${dir}-archive.md"
    printf '# %s\n\n' "${archive_title}" > "${archive_md}"
    sort -r "${list_file}" >> "${archive_md}"

    local archive_html="output/${dir}/index.html"
    export ARCHIVE_TITLE="${archive_title}"
    export PAGE_TITLE="${archive_title}"
    export CONTENT
    CONTENT="$(lowdown "${archive_md}")"
    export BREADCRUMBS=" / <a href=\"/${dir}\">${dir}</a>"
    export HEADER_EXTRA=""
    export META_DATE=""
    export META_DESCRIPTION=""
    export HAS_CODE=""
    export LANG="en"
    export DIR=""
    export IS_HOME=""

    if needs_rebuild "${list_file}" "${archive_html}" "templates/archive.html"; then
        render_page "templates/archive.html" "${archive_html}"
        echo "[archive] ${archive_html}"
    else
        log "[skip] ${archive_html}"
    fi
}

# ---------------------------------------------------------------------------
# process_projects
# ---------------------------------------------------------------------------
process_projects() {
    local list_file="${TMPDIR_BUILD}/projects.list.md"
    : > "${list_file}"

    if [[ ! -d "projects" ]]; then
        echo "[warning] projects/ directory not found"
        return
    fi

    local _proj_list="${TMPDIR_BUILD}/projects.find.list"
    find "projects" -mindepth 1 -maxdepth 1 -name '*.md' -not -name '.*' -print0 | sort -z > "${_proj_list}"

    while IFS= read -r -d '' src; do
        local title url demo sources
        title="$(get_frontmatter title "${src}")"
        url="$(get_frontmatter url "${src}")"
        demo="$(get_frontmatter demo "${src}")"
        sources_raw="$(get_frontmatter sources "${src}")"

        local slug
        slug="$(basename "${src}" .md)"
        local url_path="/projects/${slug}"
        local out_html="output/projects/${slug}/index.html"
        local tmpl="templates/project.html"

        # Build sources HTML links from "name:url,name:url" pairs
        local sources_html=""
        if [[ -n "${sources_raw}" ]]; then
            IFS=',' read -ra pairs <<< "${sources_raw}"
            for pair in "${pairs[@]}"; do
                local sname surl
                sname="${pair%%:*}"
                surl="${pair#*:}"
                # Handle URLs with double-colon (http://)
                # The format is name:scheme://rest  — re-join after first ':'
                surl="${pair#${sname}:}"
                sources_html+="<a href=\"${surl}\">${sname}</a> "
            done
            sources_html="${sources_html% }"
        fi

        # Archive entry
        printf -- '- [%s](%s)\n' "${title}" "${url_path}" >> "${list_file}"

        if ! needs_rebuild "${src}" "${out_html}" "${tmpl}"; then
            log "[skip] ${out_html}"
            continue
        fi

        local content
        content="$(lowdown "${src}")"
        check_has_code "${content}"

        build_breadcrumbs "projects/${slug}"

        export PAGE_TITLE="${title}"
        export CONTENT="${content}"
        export BREADCRUMBS
        export HEADER_EXTRA=""
        export META_DATE=""
        export META_DESCRIPTION=""
        export HAS_CODE
        export LANG="en"
        export DIR=""
        export IS_HOME=""
        export PROJECT_URL="${url}"
        export PROJECT_DEMO="${demo}"
        export PROJECT_SOURCES="${sources_html}"
        export ARCHIVE_TITLE=""

        render_page "${tmpl}" "${out_html}"
        echo "[project] ${url_path}"

    done < "${_proj_list}"

    # Archive
    local archive_md="${TMPDIR_BUILD}/projects-archive.md"
    printf '# projects\n\n' > "${archive_md}"
    cat "${list_file}" >> "${archive_md}"

    local archive_html="output/projects/index.html"
    export ARCHIVE_TITLE="projects"
    export PAGE_TITLE="projects"
    CONTENT="$(lowdown "${archive_md}")"
    export CONTENT
    export BREADCRUMBS=" / <a href=\"/projects\">projects</a>"
    export HEADER_EXTRA=""
    export META_DATE=""
    export META_DESCRIPTION=""
    export HAS_CODE=""
    export LANG="en"
    export DIR=""
    export IS_HOME=""
    export PROJECT_URL=""
    export PROJECT_DEMO=""
    export PROJECT_SOURCES=""

    if needs_rebuild "${list_file}" "${archive_html}" "templates/archive.html"; then
        render_page "templates/archive.html" "${archive_html}"
        echo "[archive] ${archive_html}"
    else
        log "[skip] ${archive_html}"
    fi
}

# ---------------------------------------------------------------------------
# process_slides
# ---------------------------------------------------------------------------
process_slides() {
    if [[ ! -d "slides" ]]; then
        log "[info] slides/ directory not found, skipping"
        return
    fi

    local list_file="${TMPDIR_BUILD}/slides.list.md"
    : > "${list_file}"

    local _slides_list="${TMPDIR_BUILD}/slides.find.list"
    find "slides" -mindepth 1 -maxdepth 1 -name '*.md' -not -name '.*' -print0 | sort -z > "${_slides_list}"

    while IFS= read -r -d '' src; do
        local title date theme
        title="$(get_frontmatter title "${src}")"
        date="$(get_frontmatter date "${src}")"
        theme="$(get_frontmatter theme "${src}")"
        [[ -z "${theme}" ]] && theme="black"

        local slug
        slug="$(basename "${src}" .md)"
        local url_path="/slides/${slug}"
        local out_html="output/slides/${slug}/index.html"
        local tmpl="templates/slides.html"

        if [[ -n "${date}" ]]; then
            printf -- '- [%s] [%s](%s)\n' "${date}" "${title}" "${url_path}" >> "${list_file}"
        else
            printf -- '- [%s](%s)\n' "${title}" "${url_path}" >> "${list_file}"
        fi

        if ! needs_rebuild "${src}" "${out_html}" "${tmpl}"; then
            log "[skip] ${out_html}"
            continue
        fi

        # Split markdown on '---' slide separators into <section data-markdown> blocks
        local slides_content
        slides_content="$(awk '
            BEGIN { in_slide=0; buf="" }
            /^---$/ {
                if (in_slide) {
                    print "<section data-markdown><textarea data-template>" buf "</textarea></section>"
                    buf=""
                } else {
                    in_slide=1
                }
                next
            }
            in_slide { buf = buf "\n" $0 }
            END {
                if (buf != "") {
                    print "<section data-markdown><textarea data-template>" buf "</textarea></section>"
                }
            }
        ' "${src}")"

        mkdir -p "output/slides/${slug}"

        export TITLE="${title}"
        export THEME="${theme}"
        export SLIDES_CONTENT="${slides_content}"

        cp "templates/slides.html" "templates/partials/slides.html"
        (cd templates/partials && mo "slides.html") > "${out_html}"
        rm -f "templates/partials/slides.html"
        echo "[slides] ${url_path}"

    done < "${_slides_list}"

    # Archive listing
    local archive_md="${TMPDIR_BUILD}/slides-archive.md"
    printf '# slides\n\n' > "${archive_md}"
    sort -r "${list_file}" >> "${archive_md}"

    local archive_html="output/slides/index.html"
    export ARCHIVE_TITLE="slides"
    export PAGE_TITLE="slides"
    CONTENT="$(lowdown "${archive_md}")"
    export CONTENT
    export BREADCRUMBS=" / <a href=\"/slides\">slides</a>"
    export HEADER_EXTRA=""
    export META_DATE=""
    export META_DESCRIPTION=""
    export HAS_CODE=""
    export LANG="en"
    export DIR=""
    export IS_HOME=""

    if needs_rebuild "${list_file}" "${archive_html}" "templates/archive.html"; then
        render_page "templates/archive.html" "${archive_html}"
        echo "[archive] ${archive_html}"
    else
        log "[skip] ${archive_html}"
    fi
}

# ---------------------------------------------------------------------------
# process_garden
# ---------------------------------------------------------------------------
process_garden() {
    local dir="${1:-garden}"
    local garden_list="${TMPDIR_BUILD}/${dir}.garden.list.md"
    : > "${garden_list}"

    local _garden_find="${TMPDIR_BUILD}/${dir//\//_}.find.list"
    find "${dir}" -mindepth 1 -maxdepth 1 -not -name '.*' -print0 | sort -z > "${_garden_find}"

    while IFS= read -r -d '' node; do
        if [[ -d "${node}" ]]; then
            local subnode_title
            subnode_title="$(get_frontmatter title "${node}/index.md" 2>/dev/null || true)"
            [[ -z "${subnode_title}" ]] && subnode_title="$(basename "${node}")"
            printf -- '- [%s/](/%s)\n' "${subnode_title}" "${node}" >> "${garden_list}"
            process_garden "${node}"
        else
            if [[ "${node}" == "${node%.md}" ]]; then
                # Non-markdown asset — copy verbatim
                cp -a --parent "${node}" output/
            elif [[ "$(basename "${node}")" != "index.md" ]]; then
                local title date lang
                title="$(get_frontmatter title "${node}")"
                [[ -z "${title}" ]] && title="$(basename "${node}" .md)"
                date="$(get_frontmatter date "${node}")"
                lang="$(get_frontmatter lang "${node}")"

                local rel="${node#${dir}/}"
                local slug="${rel%.md}"
                local url_path="/${dir}/${slug}"
                local out_html="output/${dir}/${slug}/index.html"
                local tmpl="templates/garden.html"

                render_content_page "${node}" "${out_html}" "${tmpl}" "${date}" "${lang:-en}"
                printf -- '- [%s](%s)\n' "${title}" "${url_path}" >> "${garden_list}"
                garden_count=$(( garden_count + 1 ))
            fi
        fi
    done < "${_garden_find}"

    # Build / update the index for this directory
    local garden_index_md="${TMPDIR_BUILD}/${dir//\//_}.index.md"
    local garden_title
    if [[ -f "${dir}/index.md" ]]; then
        garden_title="$(get_frontmatter title "${dir}/index.md")"
        # Append the listing to a copy of the index
        cp "${dir}/index.md" "${garden_index_md}"
    else
        garden_title="$(basename "${dir}")"
        printf '# %s\n\n' "${garden_title}" > "${garden_index_md}"
    fi
    printf '\n\n' >> "${garden_index_md}"
    cat "${garden_list}" >> "${garden_index_md}"

    local out_html="output/${dir}/index.html"
    local tmpl="templates/garden.html"

    if needs_rebuild "${garden_index_md}" "${out_html}" "${tmpl}"; then
        local content
        content="$(lowdown "${garden_index_md}")"
        check_has_code "${content}"
        build_breadcrumbs "${dir}"

        export PAGE_TITLE="${garden_title}"
        export CONTENT="${content}"
        export BREADCRUMBS
        export HEADER_EXTRA=""
        export META_DATE=""
        export META_DESCRIPTION=""
        export HAS_CODE
        export LANG="en"
        export DIR=""
        export IS_HOME=""
        export ARCHIVE_TITLE=""

        render_page "${tmpl}" "${out_html}"
        echo "[garden] output/${dir}/index.html"
    else
        log "[skip] output/${dir}/index.html"
    fi
}

# ---------------------------------------------------------------------------
# generate_rss_feed
# ---------------------------------------------------------------------------
generate_rss_feed() {
    local list_file="${TMPDIR_BUILD}/blog.list.md"
    [[ ! -f "${list_file}" ]] && return

    local out="output/feed.xml"
    mkdir -p output

    {
        cat <<'RSSHEAD'
<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
    <channel>
        <title>gumx</title>
        <link>https://gumx.cc</link>
        <description>gumx blog</description>
        <language>en</language>
RSSHEAD

        # Top 20 entries, sorted newest first
        sort -r "${list_file}" | head -n 20 | while IFS= read -r line; do
            # Line format: - [DATE] [TITLE](URL)
            local date title url
            date="$(echo "${line}"  | sed -n 's/.*\[\([0-9]\{4\}-[0-9]\{2\}-[0-9]\{2\}\)\].*/\1/p')"
            title="$(echo "${line}" | sed -n 's/.*\] \[\([^]]*\)\](.*/\1/p')"
            url="$(echo "${line}"   | sed -n 's/.*\](\([^)]*\)).*/\1/p')"
            [[ -z "${date}" || -z "${title}" || -z "${url}" ]] && continue

            # RFC 2822 date from YYYY-MM-DD
            local rfc_date
            rfc_date="$(date -d "${date}" -R 2>/dev/null || date -jf '%Y-%m-%d' "${date}" '+%a, %d %b %Y 00:00:00 +0000' 2>/dev/null || echo "${date}")"

            cat <<ITEM
        <item>
            <title>${title}</title>
            <link>https://gumx.cc${url}</link>
            <guid>https://gumx.cc${url}</guid>
            <pubDate>${rfc_date}</pubDate>
        </item>
ITEM
        done

        echo "    </channel>"
        echo "</rss>"
    } > "${out}"

    echo "[rss] ${out}"
}

# generate_sitemap
# ---------------------------------------------------------------------------
generate_sitemap() {
    local out="output/sitemap.xml"

    {
        echo '<?xml version="1.0" encoding="UTF-8"?>'
        echo '<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">'
        find output -name 'index.html' | sort | while read -r html; do
            local path
            path="${html#output}"      # /blog/hello/index.html
            path="${path%index.html}"  # /blog/hello/
            echo "    <url><loc>https://gumx.cc${path}</loc></url>"
        done
        echo '</urlset>'
    } > "${out}"

    echo "[sitemap] ${out}"
}

# ---------------------------------------------------------------------------
# build_includes
# ---------------------------------------------------------------------------
build_includes() {
    local inc_md="${TMPDIR_BUILD}/includes.md"
    printf '# includes\n\n' > "${inc_md}"
    for inc in $(find includes -type f ! -name '.*' | sort); do
        printf -- '- [%s](/%s)\n' "$(basename "${inc}")" "${inc}" >> "${inc_md}"
    done

    local out_html="output/includes/index.html"
    local tmpl="templates/base.html"

    if needs_rebuild "${inc_md}" "${out_html}" "${tmpl}"; then
        local content
        content="$(lowdown "${inc_md}")"
        check_has_code "${content}"

        export PAGE_TITLE="includes"
        export CONTENT="${content}"
        export BREADCRUMBS=" / <a href=\"/includes\">includes</a>"
        export HEADER_EXTRA=""
        export META_DATE=""
        export META_DESCRIPTION=""
        export HAS_CODE
        export LANG="en"
        export DIR=""
        export IS_HOME=""
        export ARCHIVE_TITLE=""

        render_page "${tmpl}" "${out_html}"
        echo "[built] ${out_html}"
    else
        log "[skip] ${out_html}"
    fi
}

# ---------------------------------------------------------------------------
# build_license
# ---------------------------------------------------------------------------
build_license() {
    local src="license.md"
    local out_html="output/license/index.html"
    local tmpl="templates/base.html"

    if needs_rebuild "${src}" "${out_html}" "${tmpl}"; then
        local content
        content="$(lowdown "${src}")"
        check_has_code "${content}"

        export PAGE_TITLE="license"
        export CONTENT="${content}"
        export BREADCRUMBS=" / <a href=\"/license\">license</a>"
        export HEADER_EXTRA=""
        export META_DATE=""
        export META_DESCRIPTION=""
        export HAS_CODE
        export LANG="en"
        export DIR=""
        export IS_HOME=""
        export ARCHIVE_TITLE=""

        render_page "${tmpl}" "${out_html}"
        echo "[built] ${out_html}"
    else
        log "[skip] ${out_html}"
    fi
}

# ---------------------------------------------------------------------------
# build_home
# ---------------------------------------------------------------------------
build_home() {
    local src="index.md"
    local out_html="output/index.html"
    local tmpl="templates/home.html"

    # We always rebuild home (it aggregates counts/lists from other passes)
    local home_md="${TMPDIR_BUILD}/index.home.md"
    cp "${src}" "${home_md}"

    # Inject garden count
    sed -i "s/\[%garden\]/${garden_count}/g" "${home_md}"

    # Recent blog entries
    {
        printf '\n\n## recent entries:\n\n'
        local blog_list="${TMPDIR_BUILD}/blog.list.md"
        if [[ -f "${blog_list}" && -s "${blog_list}" ]]; then
            sort -r "${blog_list}" | head -n "${LIST_COUNT}"
            local total
            total="$(wc -l < "${blog_list}")"
            [[ "${total}" -gt "${LIST_COUNT}" ]] && printf -- '- [all ..](/blog)\n'
        else
            printf -- '- stuff I wrote should be listed here\n'
        fi
    } >> "${home_md}"

    # Recent talks
    {
        printf '\n\n## talks & workshops:\n\n'
        local talks_list="${TMPDIR_BUILD}/talks.list.md"
        if [[ -f "${talks_list}" && -s "${talks_list}" ]]; then
            sort -r "${talks_list}" | head -n "${LIST_COUNT}"
            local total
            total="$(wc -l < "${talks_list}")"
            [[ "${total}" -gt "${LIST_COUNT}" ]] && printf -- '- [all ..](/talks)\n'
        else
            printf -- '- stuff I said should be listed here\n'
        fi
    } >> "${home_md}"

    # Projects
    {
        printf '\n\n## projects:\n\n'
        local proj_list="${TMPDIR_BUILD}/projects.list.md"
        if [[ -f "${proj_list}" && -s "${proj_list}" ]]; then
            head -n "${LIST_COUNT}" "${proj_list}"
            local total
            total="$(wc -l < "${proj_list}")"
            [[ "${total}" -gt "${LIST_COUNT}" ]] && printf -- '- [all ..](/projects)\n'
        else
            printf -- '- stuff I made should be listed here\n'
        fi
    } >> "${home_md}"

    # Code snippets
    {
        local code_list="${TMPDIR_BUILD}/code.list.md"
        if [[ -f "${code_list}" && -s "${code_list}" ]]; then
            printf '\n\n## code snippets:\n\n'
            head -n "${LIST_COUNT}" "${code_list}"
            local total
            total="$(wc -l < "${code_list}")"
            [[ "${total}" -gt "${LIST_COUNT}" ]] && printf -- '- [all ..](/code)\n'
        fi
    } >> "${home_md}"

    # Recipes
    {
        local recipes_list="${TMPDIR_BUILD}/recipes.list.md"
        if [[ -f "${recipes_list}" && -s "${recipes_list}" ]]; then
            printf '\n\n## recipes:\n\n'
            head -n "${LIST_COUNT}" "${recipes_list}"
            local total
            total="$(wc -l < "${recipes_list}")"
            [[ "${total}" -gt "${LIST_COUNT}" ]] && printf -- '- [all ..](/recipes)\n'
        fi
    } >> "${home_md}"

    # Slides
    {
        local slides_list="${TMPDIR_BUILD}/slides.list.md"
        if [[ -f "${slides_list}" && -s "${slides_list}" ]]; then
            printf '\n\n## slides:\n\n'
            sort -r "${slides_list}" | head -n "${LIST_COUNT}"
            local total
            total="$(wc -l < "${slides_list}")"
            [[ "${total}" -gt "${LIST_COUNT}" ]] && printf -- '- [all ..](/slides)\n'
        fi
    } >> "${home_md}"

    local content
    content="$(lowdown "${home_md}")"
    check_has_code "${content}"

    export PAGE_TITLE=""
    export CONTENT="${content}"
    export BREADCRUMBS=""
    export HEADER_EXTRA=""
    export META_DATE=""
    export META_DESCRIPTION=""
    export HAS_CODE
    export LANG="en"
    export DIR=""
    export IS_HOME="true"
    export ARCHIVE_TITLE=""

    render_page "${tmpl}" "${out_html}"
    echo "[built] ${out_html}"
}

# ---------------------------------------------------------------------------
# Main build
# ---------------------------------------------------------------------------

mkdir -p output

# Copy static assets
cp -ar static/* output/ 2>/dev/null || true
cp -ar includes output/ 2>/dev/null || true
cp -ar images output/ 2>/dev/null || true
echo "[static] assets copied"

# Content sections
process_content "blog"    "blog"   "blog archive"            "true"
process_content "talks"   "talk"   "talks & workshops"       "true"
process_content "code"    "code"   "code snippets"           "false"
process_content "recipes" "recipe" "recipes"                 "false"

# (list files already live in TMPDIR_BUILD with canonical names)

process_projects
process_slides

# Garden (count pages for home page injection)
garden_count=0
process_garden garden

# Includes + license
build_includes
build_license

# Home (uses all collected list files)
build_home

# RSS + Sitemap
generate_rss_feed
generate_sitemap

echo ""
echo "[done] Build complete. Output in output/"

# ---------------------------------------------------------------------------
# --serve
# ---------------------------------------------------------------------------
if [[ "${DO_SERVE}" == true ]]; then
    if command -v darkhttpd &>/dev/null; then
        echo "[serve] Starting darkhttpd on http://localhost:8080"
        darkhttpd output --port 8080
    else
        echo "[error] darkhttpd not found. Install it to use --serve." >&2
        exit 1
    fi
fi