#!/bin/bash
#
# BMAD Epic Execute - Design Phase Module
#
# Provides pre-implementation design phase functionality to catch
# architectural issues early before coding begins.
#
# Usage: Sourced by epic-execute.sh
#

# =============================================================================
# Design Phase Variables
# =============================================================================

# Stores the last design output for passing to dev phase
LAST_DESIGN=""

# =============================================================================
# Design Phase Functions
# =============================================================================

# Execute pre-implementation design phase
# Generates an implementation plan before coding begins
# Arguments:
#   $1 - story_file path
execute_design_phase() {
    local story_file="$1"
    local story_id=$(basename "$story_file" .md)

    # Reset last design
    LAST_DESIGN=""

    log ">>> DESIGN PHASE: $story_id"

    local story_contents=$(cat "$story_file")

    # Load architecture file if available
    local arch_contents=""
    for search_path in "$PROJECT_ROOT/docs/architecture.md" "$PROJECT_ROOT/docs/architecture/architecture.md" "$PROJECT_ROOT/architecture.md"; do
        if [ -f "$search_path" ]; then
            arch_contents=$(cat "$search_path")
            break
        fi
    done

    # Load previous decisions for context
    local decision_context=""
    if type get_decision_log_context >/dev/null 2>&1; then
        decision_context=$(get_decision_log_context)
    fi

    local design_prompt="You are a senior developer planning the implementation of a story.

## Your Task

Create an implementation plan for: $story_id

Do NOT write any code yet. Output only your design plan.

### CRITICAL RULES
- Plan thoroughly BEFORE any implementation
- Consider existing patterns in the codebase
- Map each acceptance criterion to specific files/functions
- Identify potential risks and dependencies

## Story to Plan

**Story Path:** $story_file
**Story ID:** $story_id

<story>
$story_contents
</story>

## Architecture Reference

<architecture>
$arch_contents
</architecture>

## Previous Decisions in This Epic

<decision-context>
$decision_context
</decision-context>

## Exploration Commands

First, explore the codebase to understand existing patterns:
\`\`\`bash
# Find similar implementations
find . -type f -name \"*.ts\" -o -name \"*.js\" | head -20
# Check project structure
ls -la src/ 2>/dev/null || ls -la
\`\`\`

## Required Output

Output your implementation plan in this exact format:

\`\`\`
DESIGN START
story_id: $story_id

files_to_modify:
  - path: <file path>
    action: create|modify
    purpose: <why this file needs changes>

patterns_to_use:
  - <pattern name>: <how it will be applied>

dependencies:
  - <package>: <installed|needs-install>

acceptance_criteria_mapping:
  - AC1: <which files/functions will implement this>
  - AC2: <which files/functions will implement this>

risks:
  - <potential issue and mitigation>

estimated_test_files:
  - <test file path>: <what it will test>

implementation_order:
  1. <first step>
  2. <second step>
  ...
DESIGN END
\`\`\`

Be specific and concrete. This plan will guide the implementation phase.

## Completion Signal

After outputting the design block, output exactly:
DESIGN COMPLETE: $story_id"

    if [ "$DRY_RUN" = true ]; then
        echo "[DRY RUN] Would execute design phase for $story_id"
        return 0
    fi

    local result
    result=$(claude --dangerously-skip-permissions -p "$design_prompt" 2>&1) || true

    echo "$result" >> "$LOG_FILE"

    # Extract design block
    LAST_DESIGN=$(echo "$result" | sed -n '/DESIGN START/,/DESIGN END/p')

    if [ -n "$LAST_DESIGN" ]; then
        # Save to decision log
        if type append_to_decision_log >/dev/null 2>&1; then
            append_to_decision_log "DESIGN" "$story_id" "$LAST_DESIGN"
        fi

        log_success "Design phase complete: $story_id"
        return 0
    else
        log_error "Design phase did not produce valid output"
        return 1
    fi
}

# Get the last design for inclusion in dev phase prompt
# Returns the design output or empty string if not available
get_last_design() {
    echo "$LAST_DESIGN"
}

# Build the design context block for dev phase prompt
# Returns formatted design context for inclusion in prompts
build_design_context_for_dev() {
    local story_id="$1"

    if [ -z "$LAST_DESIGN" ]; then
        echo ""
        return
    fi

    cat << EOF
## Pre-Implementation Design

The following design was created in the planning phase. Follow this plan:

<design-plan>
$LAST_DESIGN
</design-plan>

### Implementation Guidelines Based on Design

1. Follow the implementation_order specified
2. Create/modify files as listed in files_to_modify
3. Use the patterns specified in patterns_to_use
4. Ensure each acceptance_criteria_mapping is implemented
5. Be aware of the identified risks

EOF
}