#!/usr/bin/env python3
import os, sys

def load_manifest(path):
    # Minimal YAML parser for our simple manifests:
    # keys: name (ignored), include: [..], modules: [..]
    data = {"include": [], "modules": []}
    key = None
    with open(path, 'r', encoding='utf-8') as f:
        for raw in f:
            line = raw.rstrip('\n')
            s = line.strip()
            if not s or s.startswith('#'):
                continue
            if s.startswith('include:'):
                key = 'include'
                continue
            if s.startswith('modules:'):
                key = 'modules'
                continue
            if s.startswith('name:'):
                key = None
                continue
            # list item under current key
            if key in ('include', 'modules') and s.startswith('- '):
                item = s[2:].strip()
                data[key].append(item)
    return data

def resolve(path, seen):
    m = load_manifest(path)
    includes = m.get('include', []) or []
    modules = m.get('modules', []) or []
    for inc in includes:
        resolve(inc, seen)
    for mod in modules:
        if mod not in seen:
            seen.append(mod)
    return seen

def words(s: str) -> int:
    return len(s.split())

def main():
    if len(sys.argv) != 3:
        print("Usage: prompt_build.py <manifest> <out>", file=sys.stderr)
        sys.exit(2)
    manifest, out_path = sys.argv[1], sys.argv[2]
    mods = resolve(manifest, [])
    if not mods:
        print(f"No modules resolved from {manifest}", file=sys.stderr)
        sys.exit(1)
    if out_path != '-':
        os.makedirs(os.path.dirname(out_path), exist_ok=True)
    def read(p):
        with open(p, 'r', encoding='utf-8') as f:
            return f.read().strip() + "\n\n"
    parts = ["Generated Prompt Pack\n\n"]
    for m in mods:
        parts.append(f"--- {m} ---\n")
        parts.append(read(m))
    content = "".join(parts)
    # budgets
    total_words = words(content)
    BASE_BUDGET = 1200
    if total_words > BASE_BUDGET:
        print(f"ERROR: Pack exceeds budget: {total_words} > {BASE_BUDGET}", file=sys.stderr)
        sys.exit(3)
    ERRORS = 0
    MOD_BUDGET = 400
    for m in mods:
        with open(m, 'r', encoding='utf-8') as f:
            wc = words(f.read())
            if wc > MOD_BUDGET:
                print(f"ERROR: Module {m} exceeds budget: {wc} > {MOD_BUDGET}", file=sys.stderr)
                ERRORS += 1
    if ERRORS:
        sys.exit(4)
    if out_path == '-':
        sys.stdout.write(content)
    else:
        with open(out_path, 'w', encoding='utf-8') as out:
            out.write(content)
    print(f"Built {out_path} with {total_words} words across {len(mods)} modules.", file=sys.stderr)

if __name__ == '__main__':
    main()