# emit_schema.ludic — `ludicc --emit-schema FILE`: what an editor of the program's data needs, from
# the compiler's own view once the types are checked and every open registry has its entries. One
# JSON object, schema_version 1:
#
#   records     every property, state and event: its fields with their types, defaults, docs and
#               attributes (attrs.ludic)
#   registries  every registry: its record, prefix, resource file, open or not, attributes, and its
#               entries in their final order - key, constant, index, where each entry and each of its
#               field values is written - with which file contributed which entries
#   consts      every const: its type and its value as written
#   functions   every function a `fn` value can name: fn_type is the type a field sees, the states
#               stripped (the runtime supplies them), written as a field's type is ("fn(A,B)->R")
#   components  every UI component: props, state, derived fields, functions, events (emit_schema_ui)
#   natives     every native tag registered with ui_native / ui_native_input by a literal
#
# Deterministic: each list sorted by name (then file and line), an entry list in index order, the
# paths as the compiler read them, and nothing about the run. The engine's runtime is left out.
var g_schema_out: pointer = null

function schema_write(path: pointer) -> bool {
  let b = schema_buf()
  let f = file_open(path, "wb")
  if f == null { return false }
  file_write(f, buf_str(b), b.len)
  file_close(f)
  return true
}
# the schema's bytes, exactly as --emit-schema writes them
function schema_buf() -> Buf {
  let b = buf_new()
  buf_puts(b, "{\n  \"schema_version\": 1,\n  \"entry\": ")
  jq_put(b, g_mg_entry)
  buf_puts(b, ",\n  \"records\": [")
  sc_records(b)
  buf_puts(b, "\n  ],\n  \"registries\": [")
  sc_registries(b)
  buf_puts(b, "\n  ],\n  \"consts\": [")
  sc_consts(b)
  buf_puts(b, "\n  ],\n  \"functions\": [")
  sc_functions(b)
  sc_natives_find()
  buf_puts(b, "\n  ],\n  \"components\": [")
  sc_components(b)
  buf_puts(b, "\n  ],\n  \"natives\": [")
  sc_natives(b)
  buf_puts(b, "\n  ],\n  \"units\": [")
  sc_units(b)
  buf_puts(b, "],\n  \"lang\": ")
  sc_lang(b)                                      # emit_schema_lang.ludic: the keys and the languages
  buf_puts(b, "\n}\n")
  return b
}

# ---- names and text ---------------------------------------------------------------------------
# a declaration's name as written: without the module a private clash renamed it for
function sc_name(s: pointer) -> pointer {
  if s == null { return "" }
  var i = 0
  while i < len(g_rt_new) {
    if (g_rt_new[i] == s) { return g_rt_old[i] }
    i += 1
  }
  i = 0
  while i < len(g_re_new) {
    if (g_re_new[i] == s) { return g_re_old[i] }
    i += 1
  }
  return vis_plain(s)
}
# a type as written: Pool<Thing> for the instance Pool$Thing, a private record by its own name
function sc_ty(t: pointer) -> pointer {
  if t == null { return "void" }
  var out: pointer = ""
  var a = 0
  var i = 0
  let n = len(t)
  while i <= n {
    if i == n or not gen_name_ch(t[i]) {
      if i > a { out = out + sc_ty_word(t[a .. i]) }
      if i < n { out = out + t[i .. i + 1] }
      a = i + 1
    }
    i += 1
  }
  return out
}
function sc_ty_word(w: pointer) -> pointer {
  let g = gen_find(w)
  if g < 0 { return sc_name(w) }
  let args = gen_split(g_gi_args[g])
  var out = sc_name(g_gi_gen[g]) + "<"
  var i = 0
  while i < len(args) {
    if i > 0 { out = out + ", " }
    out = out + sc_ty(args[i])
    i += 1
  }
  return out + ">"
}
function sc_src_of(file: pointer) -> pointer {
  if file == null { return null }
  let s = fm_get(g_fm_src, file)
  if s == null or len(s) == 0 { return null }
  return s
}
# the text between two offsets of a file, or null
function sc_text(file: pointer, a: int, b: int) -> pointer {
  let s = sc_src_of(file)
  if s == null or a < 0 or b <= a or b > len(s) { return null }
  return s[a .. b]
}
# the comment block on the lines above a declaration (past its @attribute lines), else the comment
# that ends its own line; null when it has neither
function sc_doc(file: pointer, pos: int) -> pointer {
  let s = sc_src_of(file)
  if s == null or pos < 0 or pos >= len(s) { return null }
  var ls = pos
  while ls > 0 and s[ls - 1] != '\n' { ls -= 1 }
  let lines = new []pointer
  var e = ls
  while e > 0 {
    let le = e - 1
    var bgn = le
    while bgn > 0 and s[bgn - 1] != '\n' { bgn -= 1 }
    var k = bgn
    while k < le and (s[k] == ' ' or s[k] == '\t') { k += 1 }
    if k < le and s[k] == '#' {
      push(lines, sc_comment(s, k, le))
      e = bgn
    } else if k < le and s[k] == '@' {
      e = bgn
    } else {
      break
    }
  }
  if len(lines) > 0 {
    var out: pointer = ""
    var j = len(lines) - 1
    while j >= 0 {
      out = out + lines[j]
      if j > 0 { out = out + "\n" }
      j -= 1
    }
    return out
  }
  # the comment at the end of its own line, outside any string
  var i = pos
  var q = 0
  while i < len(s) and s[i] != '\n' {
    let c = s[i]
    if q != 0 {
      if c == CH_BACKSLASH { i += 1 }
      else if c == q { q = 0 }
    }
    else if c == '"' or c == '`' { q = c }
    else if c == '#' {
      var le2 = i
      while le2 < len(s) and s[le2] != '\n' { le2 += 1 }
      return sc_comment(s, i, le2)
    }
    i += 1
  }
  return null
}
# a comment's text: past its '#' and one space, without the end of its line
function sc_comment(s: pointer, hash: int, le: int) -> pointer {
  var a = hash + 1
  if a < le and s[a] == ' ' { a += 1 }
  var z = le
  while z > a and (s[z - 1] == ' ' or s[z - 1] == '\t' or s[z - 1] == '\r') { z -= 1 }
  return s[a .. z]
}
function sc_str(b: Buf, s: pointer) -> void {
  if s == null { buf_puts(b, "null") } else { jq_put(b, s) }
}
function sc_mod(file: pointer) -> pointer {
  let m = module_of(file)
  if m == null or len(m) == 0 { return null }
  return m
}
function sc_bool(b: Buf, v: bool) -> void {
  if v { buf_puts(b, "true") } else { buf_puts(b, "false") }
}
# a group of attributes as a JSON array
function sc_attrs(b: Buf, g: int) -> void {
  buf_puts(b, "[")
  if g >= 0 {
    var j = g_at_start[g]
    while j < g_at_start[g] + g_at_count[g] {
      if j > g_at_start[g] { buf_puts(b, ", ") }
      buf_puts(b, "{\"name\": ")
      jq_put(b, g_at_name[j])
      buf_puts(b, ", \"args\": ")
      buf_puts(b, g_at_args[j])
      if g_at_unres[j] { buf_puts(b, ", \"unresolved\": true") }
      if (g_at_name[j] == "Asset") and len(at_arg_names(g_at_args[j])) >= 2 { buf_puts(b, ", \"scope\": \"map\"") }
      if (g_at_name[j] == "Ref") and g_at_first[j] != null and pm_named(g_at_first[j]) { buf_puts(b, ", \"scope\": \"map\"") }
      buf_puts(b, "}")
      j += 1
    }
  }
  buf_puts(b, "]")
}
# "file", "line", "col" of a place
function sc_at(b: Buf, file: pointer, line: int, col: int) -> void {
  buf_puts(b, "\"file\": ")
  sc_str(b, file)
  buf_puts(b, ", \"line\": ")
  buf_puti(b, line)
  buf_puts(b, ", \"col\": ")
  buf_puti(b, col)
}
function sc_sep(b: Buf, first: bool, indent: pointer) -> void {
  if not first { buf_puts(b, ",") }
  buf_puts(b, "\n")
  buf_puts(b, indent)
}

# ---- order ------------------------------------------------------------------------------------
# indices sorted by their keys, ties kept in the order given (a merge sort)
function sc_sort(xs: []int, keys: []pointer) -> void {
  let tmp = new []int
  var i = 0
  while i < len(xs) { push(tmp, 0);  i += 1 }
  sc_msort(xs, keys, 0, len(xs), tmp)
}
function sc_msort(xs: []int, keys: []pointer, lo: int, hi: int, tmp: []int) -> void {
  if hi - lo < 2 { return }
  let mid = (lo + hi) / 2
  sc_msort(xs, keys, lo, mid, tmp)
  sc_msort(xs, keys, mid, hi, tmp)
  var i = lo
  var j = mid
  var k = lo
  while k < hi {
    if j >= hi or (i < mid and not reg_str_less(keys[xs[j]], keys[xs[i]])) {
      tmp[k] = xs[i]
      i += 1
    } else {
      tmp[k] = xs[j]
      j += 1
    }
    k += 1
  }
  k = lo
  while k < hi {
    xs[k] = tmp[k]
    k += 1
  }
}
# a key that sorts by name, then file, then line
function sc_key(name: pointer, file: pointer, line: int) -> pointer {
  var f = file
  if f == null { f = "" }
  let ln = itoa(1000000 + line)
  return name + "\t" + f + "\t" + ln
}
# a declaration the program wrote (not the runtime's, not one the compiler made)
function sc_written(d: Node) -> bool {
  return d.file != null and d.pos >= 0 and not is_runtime_file(d.file)
}

# ---- records ----------------------------------------------------------------------------------
function sc_records(b: Buf) -> void {
  let ds = new []Node
  let xs = new []int
  let keys = new []pointer
  var i = 0
  while i < len(prog) {
    let d = prog[i]
    if d.kind == N_COMP and d.s != null and sc_written(d) and gen_find(d.s) < 0 {
      push(xs, len(ds))
      push(keys, sc_key(sc_name(d.s), d.file, d.line))
      push(ds, d)
    }
    i += 1
  }
  i = 0
  while i < len(g_events) {
    let e = g_events[i]
    if e.s != null and sc_written(e) {
      push(xs, len(ds))
      push(keys, sc_key(sc_name(e.s), e.file, e.line))
      push(ds, e)
    }
    i += 1
  }
  sc_sort(xs, keys)
  i = 0
  while i < len(xs) {
    sc_record(b, ds[xs[i]], i == 0)
    i += 1
  }
}
function sc_record(b: Buf, d: Node, first: bool) -> void {
  sc_sep(b, first, "    ")
  var kind = "property"
  if d.kind == N_EVENT { kind = "event" } else if d.uns == 2 { kind = "state" }
  buf_puts(b, "{\"name\": ")
  jq_put(b, sc_name(d.s))
  buf_puts(b, ", \"kind\": ")
  jq_put(b, kind)
  buf_puts(b, ", \"module\": ")
  sc_str(b, sc_mod(d.file))
  buf_puts(b, ", \"exported\": ")
  sc_bool(b, d.vis == 1)
  buf_puts(b, ", ")
  sc_at(b, d.file, d.line, d.col)
  buf_puts(b, ", \"type_params\": ")
  if d.tps == null { buf_puts(b, "null") } else { jq_put(b, d.tps) }
  buf_puts(b, ",\n     \"doc\": ")
  sc_str(b, sc_doc(d.file, d.pos))
  buf_puts(b, ",\n     \"fields\": [")
  var n = 0
  var k = 0
  while k < len(d.kids) {
    let f = d.kids[k]
    if f.kind == N_FIELD and f.pos >= 0 {
      sc_field(b, f, n == 0)
      n += 1
    }
    k += 1
  }
  if n > 0 { buf_puts(b, "\n     ") }
  buf_puts(b, "]}")
}
function sc_field(b: Buf, f: Node, first: bool) -> void {
  sc_sep(b, first, "      ")
  buf_puts(b, "{\"name\": ")
  jq_put(b, f.s)
  buf_puts(b, ", \"type\": ")
  jq_put(b, sc_ty(f.ty))
  buf_puts(b, ", \"default\": ")
  sc_str(b, sc_text(f.file, f.sp0, f.sp1))
  buf_puts(b, ", ")
  sc_at(b, f.file, f.line, f.col)
  buf_puts(b, ", \"attributes\": ")
  sc_attrs(b, f.at)
  buf_puts(b, ", \"doc\": ")
  sc_str(b, sc_doc(f.file, f.pos))
  buf_puts(b, "}")
}

# ---- registries -------------------------------------------------------------------------------
function sc_registries(b: Buf) -> void {
  let xs = new []int
  let keys = new []pointer
  var r = 0
  while r < len(g_rg_name) {
    let v = g_rg_var[r]
    if v.file != null and not is_runtime_file(v.file) {
      push(xs, r)
      push(keys, sc_key(g_rg_name[r], v.file, v.line))
    } else {
      push(keys, "")
    }
    r += 1
  }
  sc_sort(xs, keys)
  var i = 0
  while i < len(xs) {
    sc_registry(b, xs[i], i == 0)
    i += 1
  }
}
function sc_registry(b: Buf, r: int, first: bool) -> void {
  let v = g_rg_var[r]
  sc_sep(b, first, "    ")
  buf_puts(b, "{\"name\": ")
  jq_put(b, g_rg_name[r])
  buf_puts(b, ", \"record\": ")
  jq_put(b, sc_ty(g_rg_type[r]))
  buf_puts(b, ", \"prefix\": ")
  if pm_is(r) { buf_puts(b, "null") } else { jq_put(b, g_rg_prefix[r]) }   # a map's rows have no constants
  buf_puts(b, ", \"source\": ")
  sc_str(b, g_rg_from[r])
  buf_puts(b, ", \"open\": ")
  sc_bool(b, g_rg_open[r] == 1)
  buf_puts(b, ", \"exported\": ")
  sc_bool(b, v.vis == 1)
  buf_puts(b, ", \"module\": ")
  sc_str(b, sc_mod(v.file))
  if pm_is(r) {                                     # permap.ludic: read per map at run time, per chunk when chunked
    buf_puts(b, ", \"scope\": \"map\", \"chunk\": ")
    if g_rg_chunk[r] > 0 { buf_puti(b, g_rg_chunk[r]) } else { buf_puts(b, "null") }
    buf_puts(b, ", \"maps\": ")
    jq_put(b, g_pm_root)
  } else {
    buf_puts(b, ", \"scope\": \"game\", \"chunk\": null")
  }
  buf_puts(b, ",\n     ")
  sc_at(b, v.file, v.line, v.col)
  buf_puts(b, ", \"attributes\": ")
  sc_attrs(b, g_rg_at[r])
  buf_puts(b, ", \"doc\": ")
  sc_str(b, sc_doc(v.file, v.pos))
  let order = reg_order(r)
  buf_puts(b, ",\n     \"count\": ")
  buf_puti(b, len(order))
  buf_puts(b, ",\n     \"contributors\": [")
  sc_contributors(b, order)
  buf_puts(b, "],\n     \"entries\": [")
  var o = 0
  while o < len(order) {
    sc_entry(b, r, order[o], o)
    o += 1
  }
  if len(order) > 0 { buf_puts(b, "\n     ") }
  buf_puts(b, "]}")
}
# who brought an entry in: a resource file by the declaration that read it, `def`s by their file
function sc_contrib_id(d: int) -> pointer {
  if len(g_df_src[d]) == 0 { return "def\n" + g_df_rec[d].file }
  return g_df_src[d] + "\n" + g_df_via[d]
}
# which file brought which entries in, in the order they first appear in the registry
function sc_contributors(b: Buf, order: []int) -> void {
  let seen = new []pointer
  var o = 0
  while o < len(order) {
    let d = order[o]
    let id = sc_contrib_id(d)
    var known = false
    var j = 0
    while j < len(seen) {
      if (seen[j] == id) { known = true }
      j += 1
    }
    if not known {
      push(seen, id)
      if len(seen) > 1 { buf_puts(b, ",") }
      buf_puts(b, "\n       {\"kind\": ")
      var file = g_df_src[d]
      if len(file) == 0 {
        jq_put(b, "def")
        file = g_df_rec[d].file
      } else {
        jq_put(b, "resource")
      }
      buf_puts(b, ", \"file\": ")
      sc_str(b, file)
      buf_puts(b, ", \"via\": ")
      jq_put(b, g_df_via[d])
      buf_puts(b, ", \"module\": ")
      sc_str(b, sc_mod(g_df_rec[d].file))
      buf_puts(b, ", \"keys\": [")
      var n = 0
      var p = o
      while p < len(order) {
        let e = order[p]
        if (sc_contrib_id(e) == id) {
          if n > 0 { buf_puts(b, ", ") }
          jq_put(b, g_df_key[e])
          n += 1
        }
        p += 1
      }
      buf_puts(b, "]}")
    }
    o += 1
  }
  if len(seen) > 0 { buf_puts(b, "\n     ") }
}
function sc_entry(b: Buf, r: int, d: int, index: int) -> void {
  let rec = g_df_rec[d]
  sc_sep(b, index == 0, "       ")
  buf_puts(b, "{\"key\": ")
  jq_put(b, g_df_key[d])
  buf_puts(b, ", \"constant\": ")
  jq_put(b, `{g_rg_prefix[r]}_{reg_upper(g_df_key[d])}`)
  buf_puts(b, ", \"index\": ")
  buf_puti(b, index)
  buf_puts(b, ", ")
  sc_at(b, rec.file, g_df_kline[d], g_df_kcol[d])
  buf_puts(b, ", \"fields\": [")
  var n = 0
  var k = 0
  while k < len(rec.kids) {
    let fi = rec.kids[k]
    if fi.kind == E_FINIT and fi.sp0 >= 0 {
      if n > 0 { buf_puts(b, ",") }
      buf_puts(b, "\n         {\"name\": ")
      jq_put(b, fi.s)
      buf_puts(b, ", \"value\": ")
      sc_str(b, sc_text(fi.file, fi.sp0, fi.sp1))
      buf_puts(b, ", ")
      sc_at(b, fi.file, fi.line, fi.col)
      buf_puts(b, "}")
      n += 1
    }
    k += 1
  }
  if n > 0 { buf_puts(b, "\n       ") }
  buf_puts(b, "]}")
}

# ---- consts -----------------------------------------------------------------------------------
function sc_consts(b: Buf) -> void {
  let xs = new []int
  let keys = new []pointer
  var i = 0
  while i < len(prog) {
    let d = prog[i]
    if d.kind == N_CONST and d.s != null and sc_written(d) { push(xs, i);  push(keys, sc_key(sc_name(d.s), d.file, d.line)) }
    else { push(keys, "") }
    i += 1
  }
  sc_sort(xs, keys)
  i = 0
  while i < len(xs) {
    let d = prog[xs[i]]
    sc_sep(b, i == 0, "    ")
    buf_puts(b, "{\"name\": ")
    jq_put(b, sc_name(d.s))
    buf_puts(b, ", \"type\": ")
    jq_put(b, sc_ty(d.ty))
    buf_puts(b, ", \"value\": ")
    sc_str(b, sc_text(d.file, d.sp0, d.sp1))
    buf_puts(b, ", \"module\": ")
    sc_str(b, sc_mod(d.file))
    buf_puts(b, ", \"exported\": ")
    sc_bool(b, d.vis == 1)
    buf_puts(b, ", ")
    sc_at(b, d.file, d.line, d.col)
    buf_puts(b, ", \"doc\": ")
    sc_str(b, sc_doc(d.file, d.pos))
    buf_puts(b, "}")
    i += 1
  }
}

# ---- functions a fn value can name ------------------------------------------------------------
function sc_is_state_param(p: Node) -> bool {
  return is_state_ty(p.ty) or is_state_ty(sc_name(p.ty))
}
function sc_generic_fn(names: []pointer, s: pointer) -> bool {
  let base = vis_plain(s)
  var i = 0
  while i < len(names) {
    if (names[i] == base) { return true }
    i += 1
  }
  return false
}
function sc_functions(b: Buf) -> void {
  let gens = new []pointer
  var i = 0
  while i < len(prog) {
    if prog[i].kind == N_FN and prog[i].tps != null and prog[i].s != null { push(gens, vis_plain(prog[i].s)) }
    i += 1
  }
  let xs = new []int
  let keys = new []pointer
  i = 0
  while i < len(prog) {
    let d = prog[i]
    var ok = d.kind == N_FN and d.s != null and d.tps == null and sc_written(d)
    if ok { ok = not sc_generic_fn(gens, d.s) }
    if ok { push(xs, i);  push(keys, sc_key(sc_name(d.s), d.file, d.line)) }
    else { push(keys, "") }
    i += 1
  }
  sc_sort(xs, keys)
  i = 0
  while i < len(xs) {
    sc_function(b, prog[xs[i]], i == 0)
    i += 1
  }
}
function sc_function(b: Buf, d: Node, first: bool) -> void {
  let ret = sc_ty(d.ty)
  var ps: pointer = ""
  var args: pointer = ""
  var params: pointer = ""
  var states: pointer = ""
  var k = 0
  while k < len(d.kids) {
    let p = d.kids[k]
    if p.kind == N_PARAM {
      var mt: pointer = ""
      if p.uns == 1 { mt = "mut " }
      if len(ps) > 0 { ps = ps + ", " }
      ps = ps + p.s + ": " + mt + sc_ty(p.ty)
      let bq = buf_new()
      jq_put(bq, sc_ty(p.ty))
      if sc_is_state_param(p) {
        if len(states) > 0 { states = states + ", " }
        states = states + buf_str(bq)
      } else {
        if len(args) > 0 { args = args + "," }
        args = args + sc_ty(p.ty)
        if len(params) > 0 { params = params + ", " }
        params = params + buf_str(bq)
      }
    }
    k += 1
  }
  sc_sep(b, first, "    ")
  buf_puts(b, "{\"name\": ")
  jq_put(b, sc_name(d.s))
  buf_puts(b, ", \"module\": ")
  sc_str(b, sc_mod(d.file))
  buf_puts(b, ", \"exported\": ")
  sc_bool(b, d.vis == 1)
  buf_puts(b, ", ")
  sc_at(b, d.file, d.line, d.col)
  buf_puts(b, ", \"returns\": ")
  jq_put(b, ret)
  buf_puts(b, ", \"fn_type\": ")
  jq_put(b, "fn(" + args + ")->" + ret)
  buf_puts(b, ", \"params\": [")
  buf_puts(b, params)
  buf_puts(b, "]")
  buf_puts(b, ", \"signature\": ")
  jq_put(b, `function {sc_name(d.s)}({ps}) -> {ret}`)
  buf_puts(b, ", \"states\": [")
  buf_puts(b, states)
  buf_puts(b, "], \"doc\": ")
  sc_str(b, sc_doc(d.file, d.pos))
  buf_puts(b, "}")
}

# @Unit's canonical spellings (attrs.ludic): what an editor offers and a converter reads
function sc_units(b: Buf) -> void {
  let us = at_units()
  var i = 0
  while i < len(us) {
    if i > 0 { buf_puts(b, ", ") }
    jq_put(b, us[i])
    i += 1
  }
}