// tools/hako_shared/mir_analyzer.hako - MirAnalyzerBox (Phase 161-2)
// .hako native MIR JSON v1 analyzer for JoinIR/MIR analysis
// Provides PHI/loop/if detection algorithms

// MirAnalyzerBox: Main analyzer for MIR JSON v1
box MirAnalyzerBox {
  _mir_json: MapBox         // Parsed MIR JSON root
  _functions: ArrayBox      // Cached functions array
  _verbose: integer         // Verbose mode (0=off, 1=on)

  // Constructor: Parse MIR JSON v1 from text
  birth(mir_json_text) {
    me._verbose = 0

    // Parse JSON using JsonParserBox
    me._mir_json = JsonParserBox.parse_object(mir_json_text)

    if me._mir_json == null {
      print("[MirAnalyzerBox] ERROR: Failed to parse MIR JSON")
      return null
    }

    // Extract functions array
    me._functions = me._mir_json.get("functions")

    if me._functions == null {
      print("[MirAnalyzerBox] ERROR: No 'functions' field in MIR JSON")
      return null
    }

    if me._verbose == 1 {
      print("[MirAnalyzerBox] Parsed MIR JSON successfully")
      print("[MirAnalyzerBox] Functions count: " + me._functions.size())
    }

    return me
  }

  // Validate MIR JSON v1 schema
  validateSchema() {
    if me._mir_json == null { return 0 }

    // Check required top-level fields
    local capabilities = me._mir_json.get("capabilities")
    if capabilities == null {
      print("[MirAnalyzerBox] ERROR: Missing 'capabilities' field")
      return 0
    }

    if me._functions == null {
      print("[MirAnalyzerBox] ERROR: Missing 'functions' field")
      return 0
    }

    // Check functions array is not empty
    if me._functions.size() == 0 {
      print("[MirAnalyzerBox] WARNING: Empty functions array")
    }

    if me._verbose == 1 {
      print("[MirAnalyzerBox] Schema validation: PASS")
    }

    return 1
  }

  // Summarize function metadata
  // Returns: MapBox with {name, params, blocks, instructions, has_loops, has_ifs, has_phis}
  summarize_function(funcIndex) {
    local func = me._get_function(funcIndex)
    if func == null {
      print("[MirAnalyzerBox] ERROR: Function index out of bounds: " + funcIndex)
      return null
    }

    local summary = new MapBox()

    // Basic metadata
    local name = func.get("name")
    summary.set("name", name)

    local params = func.get("params")
    if params == null {
      summary.set("param_count", 0)
    } else {
      summary.set("param_count", params.size())
    }

    // Block count
    local blocks = func.get("blocks")
    if blocks == null {
      summary.set("block_count", 0)
      summary.set("instruction_count", 0)
      summary.set("has_phis", 0)
      summary.set("has_loops", 0)
      summary.set("has_ifs", 0)
      return summary
    }

    summary.set("block_count", blocks.size())

    // Count instructions and detect patterns
    local total_instructions = 0
    local has_phi = 0
    local has_branch = 0

    local i = 0
    loop(i < blocks.size()) {
      local block = blocks.get(i)
      local instructions = block.get("instructions")

      if instructions != null {
        total_instructions = total_instructions + instructions.size()

        // Check for PHI and Branch instructions
        local j = 0
        loop(j < instructions.size()) {
          local inst = instructions.get(j)
          local op = inst.get("op")

          if op == "phi" {
            has_phi = 1
          }

          if op == "branch" {
            has_branch = 1
          }

          j = j + 1
        }
      }

      i = i + 1
    }

    summary.set("instruction_count", total_instructions)
    summary.set("has_phis", has_phi)
    summary.set("has_ifs", has_branch)

    // Loop detection (basic backward edge check)
    local has_loop = me._has_backward_edge(blocks)
    summary.set("has_loops", has_loop)

    if me._verbose == 1 {
      print("[MirAnalyzerBox] Summary for " + name + ":")
      print("  Blocks: " + blocks.size())
      print("  Instructions: " + total_instructions)
      print("  Has PHI: " + has_phi)
      print("  Has Branch: " + has_branch)
      print("  Has Loop: " + has_loop)
    }

    return summary
  }

  // Count PHI instructions in function
  // Returns: ArrayBox of {block_id, dest, incoming_count}
  count_phis(funcIndex) {
    local func = me._get_function(funcIndex)
    if func == null {
      print("[MirAnalyzerBox] ERROR: Function index out of bounds: " + funcIndex)
      return null
    }

    local blocks = func.get("blocks")
    if blocks == null {
      return new ArrayBox()
    }

    local phi_list = new ArrayBox()

    local i = 0
    loop(i < blocks.size()) {
      local block = blocks.get(i)
      local block_id = block.get("id")
      local instructions = block.get("instructions")

      if instructions != null {
        local j = 0
        loop(j < instructions.size()) {
          local inst = instructions.get(j)
          local op = inst.get("op")

          if op == "phi" {
            local phi_info = new MapBox()
            phi_info.set("block_id", block_id)

            local dest = inst.get("dst")
            phi_info.set("dest", dest)

            local incoming = inst.get("incoming")
            if incoming == null {
              phi_info.set("incoming_count", 0)
            } else {
              phi_info.set("incoming_count", incoming.size())
            }

            phi_list.push(phi_info)

            if me._verbose == 1 {
              print("[MirAnalyzerBox] PHI found: block=" + block_id + " dest=" + dest)
            }
          }

          j = j + 1
        }
      }

      i = i + 1
    }

    return phi_list
  }

  // Count loops in function (via CFG backward edge detection)
  // Returns: integer count of loops detected
  count_loops(funcIndex) {
    local func = me._get_function(funcIndex)
    if func == null {
      print("[MirAnalyzerBox] ERROR: Function index out of bounds: " + funcIndex)
      return 0
    }

    local blocks = func.get("blocks")
    if blocks == null {
      return 0
    }

    // Build block_id -> block_index map for quick lookup
    local block_map = new MapBox()
    local i = 0
    loop(i < blocks.size()) {
      local block = blocks.get(i)
      local block_id = block.get("id")
      block_map.set("" + block_id, i)
      i = i + 1
    }

    // Count backward edges (target_id < source_id)
    local loop_count = 0

    i = 0
    loop(i < blocks.size()) {
      local block = blocks.get(i)
      local block_id = block.get("id")
      local instructions = block.get("instructions")

      if instructions != null {
        // Check last instruction for control flow
        local last_idx = instructions.size() - 1
        if last_idx >= 0 {
          local last_inst = instructions.get(last_idx)
          local op = last_inst.get("op")

          // Check jump instruction
          if op == "jump" {
            local target = last_inst.get("target")
            if target != null {
              if target < block_id {
                loop_count = loop_count + 1

                if me._verbose == 1 {
                  print("[MirAnalyzerBox] Backward edge: block " + block_id + " -> " + target)
                }
              }
            }
          }

          // Check branch instruction (both targets)
          if op == "branch" {
            local then_target = last_inst.get("then")
            local else_target = last_inst.get("else")

            if then_target != null {
              if then_target < block_id {
                loop_count = loop_count + 1

                if me._verbose == 1 {
                  print("[MirAnalyzerBox] Backward edge (then): block " + block_id + " -> " + then_target)
                }
              }
            }

            if else_target != null {
              if else_target < block_id {
                loop_count = loop_count + 1

                if me._verbose == 1 {
                  print("[MirAnalyzerBox] Backward edge (else): block " + block_id + " -> " + else_target)
                }
              }
            }
          }
        }
      }

      i = i + 1
    }

    return loop_count
  }

  // Enable/disable verbose mode
  set_verbose(enabled) {
    if enabled == 1 {
      me._verbose = 1
      print("[MirAnalyzerBox] Verbose mode: ON")
    } else {
      me._verbose = 0
    }
  }

  // Internal: Get function by index
  _get_function(funcIndex) {
    if me._functions == null { return null }
    if funcIndex < 0 { return null }
    if funcIndex >= me._functions.size() { return null }

    return me._functions.get(funcIndex)
  }

  // Internal: Check if function has backward edges (loop indicator)
  _has_backward_edge(blocks) {
    if blocks == null { return 0 }

    local i = 0
    loop(i < blocks.size()) {
      local block = blocks.get(i)
      local block_id = block.get("id")
      local instructions = block.get("instructions")

      if instructions != null {
        local last_idx = instructions.size() - 1
        if last_idx >= 0 {
          local last_inst = instructions.get(last_idx)
          local op = last_inst.get("op")

          if op == "jump" {
            local target = last_inst.get("target")
            if target != null {
              if target < block_id {
                return 1
              }
            }
          }

          if op == "branch" {
            local then_target = last_inst.get("then")
            local else_target = last_inst.get("else")

            if then_target != null {
              if then_target < block_id {
                return 1
              }
            }

            if else_target != null {
              if else_target < block_id {
                return 1
              }
            }
          }
        }
      }

      i = i + 1
    }

    return 0
  }
}

// Main entry point for standalone testing
static box MirAnalyzerMain {
  main(args) {
    print("[MirAnalyzerMain] Phase 161-2 Basic MirAnalyzerBox Implementation")
    print("[MirAnalyzerMain] Usage: provide MIR JSON file path as argument")

    // TODO: Add file reading and analysis test
    return 0
  }
}